Radiation effect on DNA

DNA is double stranded large molecule with phosphoric acid, pentose sugar (2-deoxy-D-ribose) and organic bases. Phosphate moiety binds to the 5C of one end, the 3C of the neighbor pentose sugar to produce phosopho-diester linkage. The organic bases found in DNA are heterocyclic compounds containing nitrogen in their rings. So these are called nitrogenous bases. DNA normally contains adenine (A), guanine (G), thymine (T) and cytosine (C). Organic bases are linked with the pentose molecule to form nucleosides. This nucleoside binds with the phosphate group to form nucleotides.       

In DNA double helix number of pyrimidine bases is equal to that of purine bases. The two strands in a DNA are called complementary strands. The hydrogen bonds between A and T, and between C and G is known as complementary base pairing. There will be two hydrogen bonds between A and T, three hydrogen bonds between C and G. The chemical structure of DNA was shown in the figure1. DNA molecules are large molecules and packed into structures called chromosomes with the help of proteins (both histones and non-histones). Chromosomal aberrations may occur due to ionizing radiations. DNA is the primary target for cell damage from ionizing radiation compare to others which leads to mutations.

Mutations are sudden heritable changes. Agents which are responsible for inducing the mutations are called mutagens. Mutagens are of two types (physical mutagens and chemical mutagens). Physical mutagens are of types (non-ionizing and ionizing radiations). Alfa, beta and gamma radiations are ionizing radiations. They cause ionization of atoms in their path. So they are called ionizing radiations.
   
Alpha and beta radiations are particulate radiations, which consists of high energy atomic particles generated due to radioactive decay. Alpha rays are composed of alpha particles having two protons and neutrons devoid of electrons so they consist of double positive charge. Where as beta rays are high energy electrons produced by radioactive decay of 3H, 32P and 35S etc., and they are negatively charged. Gamma radiations are high energy radiations composed of photons. Gamma rays are non particulate rays. These are produced by decay of radioactive isotopes of 14C, 60C etc., Ionizing radiation remove the electron from its orbit around the nucleus of an atom.
   
Electron ejected from the atom A resulted in positive charge of the atom
Gamma rays produce ions in the above manner (Fig 2).  A high energy photon loses a part of its energy in removing electron from its orbit. The chemical effects of radiations are produced primarily due to ionization. The genetic effects of radiation result of their effects on DNA. The changes in DNA includes change in base (base substitution), loss of base (deletion and addition), disruption of hydrogen bond between nitrogen bases, single and double strand breaks and also cross linkage of proteins. Change in bases will produce missense, nonsense and frame-shift mutations. This will leads to gene mutations. Pyramidines are more sensitive to radiation when compare to purines.

The radiation damage to DNA occurs through two mechanisms (direct and indirect mechanisms). DNA damage caused by alpha, beta and gamma rays occurs when the displaced electron ionizes a water molecule, creating a free radical. As the free radical drifts, it may disrupt a DNA molecule. Direct damage is due to in which electron loss and electron gain within the DNA molecule which leads to instability of DNA molecule. Direct mechanism plays a more significant contribution to the DNA damage when compared to the indirect mechanism. Direct damage is predominant with alpha particles and indirect damage is predominant with gamma rays.             

Pospho di ester linkage break
The changes in the secondary structure of DNA caused by ionizing (gamma) radiations were studied by using circular dichroism and differential pulse polarography. Increase of the polarographic reducibility of DNA was observed on application of relatively low doses of radiation. Irradiation of DNA with low doses of gamma radiation induced local changes in angles and distances between the bases in the DNA double helix. Denatured DNA appeared after irradiating DNA with higher doses of ionizing radiation

Certain genes are responsible for rapid cell division which is called as oncogenes. Some other genes that slow down cell division and ultimately lead to cells death are called tumor suppressor genes. Cancers can be caused by DNA mutations (changes) that induce oncogenes or suppress tumor suppressor genes. First radiation-induced skin cancer reported in 1902. In 1920 bone cancer was observed among radium painters and in 1930 liver cancer was identified in Throtrast administration. However most DNA mutations related to breast cancer.

In view of the reaction mechanism proposed by Lewis, the reactions of metals and acids with certain species are very similar. In the Lewis mechanism, electron-deficient species such as metal cations, the hydrogen ion of acids and positively-charged species react with electron-rich species such as anions, hydroxide ions and molecules with free electrons to form new chemical bonds that even out the imbalanced electron distribution, in reactions like neutralization for acids and oxidation for metals (Whitten, 2004).
   
In the body, the production of acid for digestion is a well-regulated process, and the body has several organs and secretions that ensure that stomach acid levels do not get too high. There are possibly medications that could regulate the production of acid (probably antihistamines, according to someone I asked for opinion), but as these medications could upset the bodys proper functioning, neutralization of excess acid by the take-in of sodium bicarbonate seems to be better.
   
On the whole, the body can be thought of as one large chemistry set. The blood, for instance, is a complex system that exhibits fascinating chemistry, capable of delivering carbon dioxide out of the body via a chemical buffering system and also delivering oxygen to its parts via the binding of oxygen to an ion-molecule complex found in blood. Gastric acid is a solution composed primarily of hydrochloric acid. Urine is composed of organic urea and waste products dissolved in water.
   
The body is a well-regulated chemical system, and does not allow the presence of foreign chemical agents, which it rids itself of by metabolizing it into a form that it can easily dispose. Problem ensues when the product of metabolism is more toxic than the original compound. Taking in too much paracetamol, for instance, results in both liver failure and kidney failure, due to the liver being unable to neutralize the excess toxic product of paracetamol metabolism.

Five Basic Elements

The five elements in most ancient pagan cultures are the air, earth, water, fire and void. Each of the elements has a specific aspect associated with it. Fire can destroy and also build. It can also change something to another type. It has force therefore has to be contained. It is used to symbolize courage, strength zeal. In me, it signifies the hidden power that is within me that can be used in transforming any situation affecting me and also getting rid of any negativity about doubting the potential that is within me. The earth is used to symbolize the mother who sustains life through being generous with its resources in order to nurture all life on it. When I look around and see how much the earth bestows for us, am just inspired to share my resources with the less fortunate.

Water in most cultures signifies clarity, healing, purity and psychisim. In me, it signals that there is the ability within me of remaining true to my principles. Air is given the attribute of movement, refreshment and energy in most cultures. These attributes add in me the zeal to always step out of my comfort zone and seek better areas of improving my situation. The most vital of all these elements is balance. All these elements when they are in balance, their behavior can be established but when they are not, their behavior becomes unpredictable (Kotelnikov, 2008). 

When we fail to plan our lives in a balanced manner and overindulge in areas that do not add value to our life, our lives can become uncontrollable and unpredictable just like these five elements. All these elements interact between themselves in a series of cycles that are either destructive or productive. We should learn to embrace the fact that there will be destructive cycles and productive ones in this life in order to be well prepared to handle of all them well when they happen.

Carbon dioxide emission and the environment

Carbon dioxide emissions have been the greatest threat to the self sustaining ecosystem. Scientists have argued that reducing the emission of carbon dioxide in the atmosphere will divert the current degradations of the ecosystem which threatens life in the planet. Despite these claims, there have been increased emissions of carbon dioxides into the atmosphere as the use of fossil fuels increases due to the high demand for energy in the global economy. This situation has been made worse by clearing of forests to create land for settlement and agriculture due to increased world populations. The forest acts as a natural regulator of the amount of carbon dioxide in the atmosphere. This trend has raised the issue of whether the worldwide economical, industrial and social development is prepared to confront the unprecedented environmental crisis associated with high carbon dioxide emissions. In theory, the world society may seem to be determined to reduce the concentration of carbon dioxide in the atmosphere but practically these attempts are hoax.
   
Since the industrial revolution over a century ago, the world society has not been prepared for or was not even aware of the environmental implications of industrialization. For that reason, the concentrations of carbon dioxide in the atmosphere has increased significantly since the industrial revolution reaching at alarming level and is expected to rise more rapidly as the world becomes more industrialized. The concentration of carbon dioxide in the atmosphere has increased from 280 ppm before the industrial revolution to over 380 ppm. This level of carbon dioxide is the highest ever experienced in the planets history. Despite this trend, the implementation of mitigation measures to reverse the situation have not been forth coming due to the short term cost that are associated with adoption of environment friendly sources of energy. There are several negative effects of taking these measures due to the time constant and cost for deployment of necessary technologies. However, these economic impacts are nothing compared to the effect of carbon dioxide emission to the ecosystem (ASME, 2009).   
   
The environmental implications of these high amounts of carbon dioxide in the atmosphere together with other greenhouse gases are far reaching. The cost of these implications in the ecosystem and the human society can be directly attributed to lack of proper mitigations measures. The interventions to the increased carbon dioxide emission especially in the developed countries throughout the 20th century have not been swift enough leading to the resultant climate change. Research indicates that the climate change being experienced in the world today can only be averted if the carbon dioxide emissions are reduced. 

The major problem associated with the control of carbon dioxide emissions in the world is the high dependence on fossil fuel by the mechanized economy of the world. The economic issues associated with the complex fossil fuel constrained industrial world have made the intervention suggested by scientists impractical to some extent. However, these interventions are within reach both technically and economically but require integrated efforts between all the governments of the world, major players in the industrial world, the society and the scientists. Moreover, more investment in industrial research is required to demonstrate the feasibility of the proposed intervention by developing and enabling cost effective technologies. As the world economy changes, the relevant authorities should be very vigilant in the implementation of the proposed measures which will significantly reduce the emission of greenhouse gases especially carbon dioxide (ASME, 2009).

All of the matters in the universe are composed of atoms or elements. These elements are very minute particles. Elements come in group to produce the matter that humans can see. Matters that have a specific proportion of the type of elements are called compounds. Water for example is composed of 2 parts hydrogen and 1 part oxygen by number of atoms. If in case a given substance contains 3 hydrogen atom and 1 oxygen atom, then even if it composed of hydrogen and oxygen, it will never be  considered as water. Like elements, compounds are considered as pure substances. There are also combinations of substances that are not affected by the proportion of the combined substances and cannot be separated into elements by physical means. They can only be separated into elements using chemical means. These are called mixture. Example of these is a mixture of salt and water. Even if the proportion of salt to water in the mixture varies, the resulting mixture will still be a salt water mixture. Unlike compounds, mixtures are not considered as pure substance and can be separated into other substances by physical means (Kotz  Treichel, 1996).

Compounds are generally named using the names of the elements that composed them. Hence, it a pure substance can be classified as either element or compound by knowing its name. A complete list of known elements and their chemical symbols is listed in many references. It the name of the pure substance is included in the list, it is an element. However, the reverse is not always true since there are compounds that are composed of only 2 or more of the same element. A more accurate way is by knowing its chemical formula. If the chemical formula of the pure substance is composed of different chemical symbols of elements or if it is composed of more than one atom of an element, then it is a compound. The disadvantage of this is that the chemical formula is not always readily available. Other methods are necessary, like line emission spectra. This technique utilizes the fact that an element possesses unique line spectra. If the pure substance showed line spectrum of different elements, then it is a compound.

Elements do not readily group with other elements to form a compound. Some rules are satisfied first before a compound is formed and these rules depend on the nature of element, such as its charge. If the elements to be combined are both negatively charged, the compound is called covalent compounds and the bonds that exist between the elements are called covalent bond. If it is composed of elements of opposite charge, it is called ionic compounds and the bonds that exist between the elements are called ionic bond (Carpi, 1999). 
 Ionic bond is easy to understand. It is well known that opposite charges attracts while same charges repeal. Since the charges of the elements present in ionic compounds are opposite, the elements will attract each other by electrostatic force. The charge also reflects the need to give up or attain electrons. A negative charge indicates that the atom requires additional electrons while positive charge indicates the need to give up electrons. Since the charges of elements in ionic compound are opposite, one must give up and while one must accept electron. In this process, the bond between elements in ionic compounds is produced. Example of these compounds are CaBr2 (calcium bromide) and NaCl (sodium chloride).

The bonds for covalent compounds are produced in a different way. It can be expected that the elements will repeal each other due to them having the same size, but in reality bonds are still formed. Since all the elements are negatively charged, all must accept electron. However, no other source of electron is present and so the only solution is for the elements to share electrons. The shared electron becomes property of the forming elements. Examples of these compounds are NF3 (nitrogen trifluoride) and PCl3 (phosphorus trichloride) (Kotz  Treichel, 1996).

CHEMISTRY

What are the most important concepts you have learned this week   
The concepts regarding Acids and Bases are the important concepts presented today. In the field of chemistry these 2 are essential in the study and understanding the difference among substances. We can differentiate various substances by identifying them by these 2 classifications. I have also learned about the concepts regarding pH Balance and its connection with the presence of hydrogen ions.

What would you recommend to your managementleadership based on these concepts   
Based on these concepts substances can be accurately measured and identify by applying basic chemistry concepts such as these. Further studies and even experimentation can be recommended.   

How will these concepts impact you personally and professionally  
These have impact my prior knowledge and concepts of materials and substances around. Even substances need to be balance and to recognize their extremes. Everything has its uses or advantages. There is also a need to balance things out and anything that is too much or too little can cause some harm. For example, too much acid in the stomach is not good after all.
What is the value added from these concepts, or what differences can these concepts make to your organization
   
These concepts can provide patterns or suggestions on how we can balance things. The concepts can be applied to determine chemical reactions among substances.
Describe important references used this week.
   
The references used this week include articles that provide introductory explanations as well as sample lab exercises regarding Acids and Bases. These references provided overview of the topic as well as clear examples, definitions and chemistry concepts.

CHEMISTRY

How do over-the counter calcium carbonate or magnesium carbonate antacid medications work
   
Calcium carbonate (CaCO3 ) and magnesium carbonate (MgCO3) are 2 of the most common compounds found in many commercial OTC antacids. Antacids are basically known as base or alkaline and therefore are capable to neutralize acids. They worked by effectively neutralizing the acid mainly known as Hydrochloric acid (HCl) secreted in the stomach. When in excess, HCl can bring what we call hyperacidity or heartburn. HCl is actually an important compound found in gastric juices and is being secreted in the stomach for the enzyme pepsin to catalyze the digestion of proteins.
 Antacids moreover are also known as weak bases as they have pH level of 10 and considering the highest is pH level of 14. Antacids do helped reduce the level of acids in the stomach, but since HCl is an important part of the gastric juice the antacids need not be too strong to neutralize the acids.
    In the process of neutralization acids are known to release H  or hydrogen ions while bases release OH-. This would result in producing either water (H2O) and even salts. Chemical reaction will then take place in the stomach and the HCl will be reduced through neutralization.  After which, it can release either water, salt or even carbon dioxide gas such as in this sample chemical formula or equation of  CaCO3   2HCl  CaCl2 H2O  CO2.

The Ferrocene Discovery

Ferrocene was known as the first sandwich compound. A sandwich compound is when a metal is placed between two parallel and planar ring structures.  Ferrocene has a molecular weight of 186.04 gmol, a boiling point of 249 , and a melting point of 172.5 (Mays 2).  It was discovered in 1951. In 1950, R.D. Brown, a professor at the University of Melbourne, predicted that fulvalene was actually not a benzoid molecule, but an aromatic hydrocarbon as seen below.

Peter Pauson, a post-doctorate at Duquesne University in Pittsburgh, Pennsylvania, and his student, Thomas J. Kealy, tested his theory.  They used FeCl3  (iron (III) chloride) to oxidize dihydrofulvalene directly to fulvalene.  They created dihydrofulvalene by heating cyclopentadienylmagnesium bromide with iron (III) chloride in ether and decomposing it with iced ammonium chloride solution. 

6C5H5MgBr  2FeCl33C10H10Fe  3MgBr2  3MgCl2  Fe
The final product was actually bis (cyclopentadienyl) iron (II) or C10H10Fe it was an orange solid and very stable in water, base, acid, and even with boiling (Kauffman 185).  To confirm if iron was present, they boiled the compound extensively with nitric acid.  The final formulation was as follows

 The compound was definitely aromatic. They submitted their article to the Journal of the Chemical Society on August 7, 1951. The research team of the British Oxygen Company, Ltd, which consisted of Samuel A. Miller, John A.Tebboth, and John F. Tremaine, had actually made the same discovery in 1948 by reacting reduced iron with cyclopentadiene vapor in a nitrogen atmosphere at 300C (Kauffman, 185).  However, they did not submit their article until July 11,1951.

In 1973, Geoffrey Wilkinson and Ernst Otto Fischer won the Nobel Prize in chemistry for their development work on sandwich compounds for transition metals such as iron (Kauffman 185). On April 20, 1952, Geoffrey Wilkinson, Myron Rosenblum, Mark C. Whiting, and R.B. Woodward published an article in the Journal of the American Chemical Society discussing the sandwich structure for ferrocene.  It was given that name since it was similar to benzene.  They favored the antiprismatic structure due to their X-ray diffraction studies.  Their research was based on magnetic susceptibility, infrared absorption spectrum, and dipole moment measurements (Kauffman, 186).  The structure is seen below.

Ferrocene contains 30 iron by weight and can be used as a source of iron in fuel additives (May 1). It is sold as a liquid and a solid however, when it is used in the solid form as a combustible catalyst, it produces negative results.  The reason is that if its used in crumbs, there is that possibility that it may not completely dissolve.  If caplets have poor dissolution rates, you will get unfavorable results (May 5).  When using ferrocene as a fuel additive, it is best to dissolve it in a compatible aromatic solvent such as pyridine (May 3)
Ferrocenylated amino acids and peptides have been intensely studied in the recent past mainly due to their attractiveness as redox-active biomedical probes and structural models for peptides  (tpni
ka 149). Ferrocene-amino acid conjugates such as 2-(methoxycarbonyl)methyl-2-aza 3ferrocenophane, result from ferrocene combined with an amino acid ester and a catalyst. Scientists Peter Quirk and Byron Kratochvil were able to determine the purity of ferrocene derivatives by performing oxidation with Copper (II) in acetonitrile. Copper (II) perchlorate makes an excellent titrant (Kratochvil 536).  Purifying commercial ferrocene by recrystallization and sublimation makes it stable. The purity of many of the derivatives, with n-butyl and t-butylferrocene being the most pure, ranged from 93 to 100 percent (Kratochvil 536).

In conclusion, various researchers contributed to the discovery of ferrocene.  Iron is the best metal for a catalytic effect.  As it has already been stated, it is used as a fuel additive.  It is also used to prepare amino acids and peptides.  Ferrocene is also highly soluble in aromatic solvents.  It is easy to see how it was the basis for a Nobel Prize.

VIdentification of an Unknown Drug Sample

Learning to identify unknown chemicals has myriad advantages, from simply checking the steps when synthesizing a chemical product, to chemical analysis of a potentially toxic environment. In particular, identifying unknown drug samples has very useful applications in pharmaceutical quality control, as well as forensics. From knowing whats exactly in a new medicine before distributing it for public consumption to something as dramatic as finding the cause of to an overdose, these are just a few examples of the importance of drug identification.

The objective of the experiment is to be able to identify a sample of an unknown drug. For this particular experiment, the unknown drug is identified from a list of six possible substances, namely Salicylamide, Paracetamol, 4-Aminosalicylic Acid, Benzocaine, 3-Aminoacetophenone, and 4-Hydroxy Acetophenone. The sample is identified using physical and chemical tests, such as appearance, acidity and solubility functional group tests and analysis of the samples Infrared and Ultra-violet spectra.
Other than the main objective, other supplementary skills developed in this exercise are determining the presence of functional groups which is useful for testing organic substances, extracting valid information from IR and UV spectra, and the critical thinking applied in the step-by-step elimination of the other possible answers.

Chemical Structures of Possible Drug Substances
Salicylamide

Paracetamol or
Aminophen
4-Aminosalicylic Acid
Benzocaine

4-Hydroxy Acetophenone
3-Aminoacetophenone

2. METHODS, RESULTS, and INFERENCE
A. Physical and Chemical Tests
MethodResultInferenceSmellOdourlessPossibly no ether presentAppearanceWhite powderNA(All are white powder)Heat on nickel foilCool (no heat)No reaction to nickelAction to damp blue litmusTurns redAcidicAction to damp red litmusNo reactionPossibly acidicSolubility in 6 drops distilled water                 UndissolvedInsoluble in H2OSolubility in 6 drops HCl (dil)                         DissolvedPossibly a weak baseSolubility in 6 drops NaOHPartially dissolvedAcidic, may contain acidic functional groupPresence of NitrogenRed to Blue Litmus,
Nitrogen is presentHas Nitrogen-containing functional groups
B. Functional Group Tests
MethodResultInferencePhenolic OH group testYellowNo phenolic OH groupCarbonyl group testYellow precipitateCarbonyl group present
Ester group testDark, almost brownish, redEster group presentAmide group testPinkNo amide groupPrimary aromatic amine group testDark red colorPrimary aromatic amine presentN-arylamide group testNANA

3. INTERPRETATION OF UV AND IR SPECTRA
 SHAPE   MERGEFORMAT 
A. Infrared Spectra 
Primary aromatic amine is distinguishable with the NH2 absorbance peaks (transmittance troughs) at 3300-3400cm-1 while an O-H stretching band can be seen between 3200-3600 cm-1 (rather broad). There are strong Aromatic CH bands at around 3000cm-1, while aliphatic CH stretching bands can be seen at 2850-2950cm-1. Theres a strong Carbonyl signal at around 1700cm-1 and the presence of the Ester group is confirmed by the absorbance peaks at around 1685cm-1 with CO stretching at 1280cm-1.

B. Ultra-Violet Spectra
In H2O, the ultra-violet spectra of the unknown sample peaks at 290nm, 220nm, and around 200nm. In HCl however, the peaks are at around 225nm and 270nm. Basing on the highest peaks, and because the wavelengths are not convergent, this is a hypsochromic shift. These peaks are rather expected though, because just basing on the solubility tests, it was shown that the unknown drug sample is insoluble in water while soluble in Hydrochloric acid.

4. DISCUSSION AND CONCLUSION
For the initial physical tests, while most of the possible substances are white powders, samples like 3-Aminoacetophenone can be outright eliminated as it is usually found to be light brown. This can be rather inconclusive though, for 4-Aminosalicylic acid which can be described as beige or off-white. The lack of an odour could also mean it was too slight as to be undetected rather than conclusive, but it does present the possibility than no ether group is present. The reaction of the litmus paper though, indicated a substance with a low pH, thus possibly eliminating the strong bases in the possible substances. The insolubility of the unknown in H2O eliminates Salicylamide since this is soluble in water. Now the presence of Nitrogen effectively eliminates 4-Hydroxy Acetophenone since this is the only substance of the five that has does not contain any Nitrogen. Now the functional group tests and Infrared spectra analysis are thus far the most conclusive. The lack of phenolic OH in itself would eliminate all the possible substances with OH in their respective chemical structures. Now with the elimination of all the other possible drug substances, plus the strong presence of the ester group and the UV spectra, it can thus be concluded that the unknown drug is Benzocaine.

Metformin or dimethylbiguanide is an orally-adminstered antihyperglycaemic drug used to treat patients with non-insulin dependent diabetes mellitus which acts by improving insulin sensitivity which in turn decreases insulin resistance (Bailey et al., 1996). The structure of metformin has nitrogen-containing functional groups, particularly amine and imine functional group and contains a guanidino group. Based on its structure, it can be deduced that the drug is prone to hydrolysis of the imine functional groups as well as oxidation and reduction of both amine and imine groups. Therefore, the possible degradation products that can be inferred from this are guanidine, amines and amides.

For a molecule such as metformin which would be susceptible to hydrolysis and redox, contact with moisture and air should be avoided by keeping the product in a dry place and ensuring that the containers are almost, if not, air tight and tightly closed.

Nateglinide  Nateglinide is a novel D-phenylalanine derivative that stimulates the prandial release of insulin through the inhibition of the ATP-sensitive K channels in pancreatic -cells in the presence of glucose (Dunn and Faulds, 2000), which makes it chemically and pharmacologically unique among oral anti-diabetes drugs (Horton et al., 2000). The functional groups present in nateglinide, include amide, carboxyl and aromatic functional groups. All these groups can undergo hydrolysis as well as redox reactions leading to the production of D-phenylalanine, amides, amines, and possibly secondary alcohol (from the hydrolysis of the carboxyl group) as degradation products.

Given a molecule such as nateglinide, which would be very prone to hydrolysis, contact with moisture should be avoided by keeping it in a dry place andor putting a dessicant with it in the container. Keeping its container airtight would also be a helpful precaution which should be taken to avoid contact with air which also contains a significant amount of moisture depending on the relative humidity.

Pioglitazone
Pioglitazone belongs to a relatively new class of insulin-sensitizing agents known as thiazolidinediones used to treat type II diabetes mellitus non-alcoholic steatohepatatis or fatty liver (Miyazaki et al., 2002). It exists as a racemic mixture of enantiomers which may inter-convert in vivo but no differences in the pharmacologic activity was found between the two (Eckland and Danhof, 2000). The structure of this drug contains pyridine, ketone, ethoxy, sulfonyl and phenyl groups. The ketone, ethoxy and sulfoxide groups can undergo hydrolysis and redox reactions thereby leading to pyridine, phenyl, sulfoxide derivatives as possible major degradation products of the drug.
Similar to nateglinide, pioglitazones structure is also prone to hydrolysis, hence, contact with moisture should also be avoided as mentioned earlier.

Tolbutamide
Tolbutamide is a first generation potassium channel blocker, sulfonylurea oral hypoglycemic drug used in the management of type II diabetes if diet alone is not effective. However, it is not routinely used due to the higher incidence of adverse effects. Contrary to this, due to its short duration of action and rapid metabolism, the drug proves to be safe for use in elderly diabetics. The functional groups present in tolbutamides structure which are prone to hydrolysis and redox reactions are the phenyl, sulfonyl and amide groups. Possible degradation products of tolbutamide are p-toluenesulfonamide and butylisothiocyanate as well as phenyl, amide and sulfoxide derivatives.

olbutamide structure would be susceptible to hydrolysis and oxidation, therefore, keeping it in a dry place, placing a dessicant in its container and ensuring its container is airtight are precautions that should be employed to avoid its degradation while in storage.

Repaglinide
Repaglinide is an oral hypoglycemic agent, belonging to a new chemical class of  insulin secretagogues (Moses et al., 1999). It possess all characteristics that are desired for treating type II diabetes patients such rapid absorption, short metabolic half-life (1 hour) (Wolffenbuttel et al., 1993), and novel insulin release profile (Graul and Castaer, 1996). The structure of repaglinide has carboxylic, ether, amide and phenyl functional groups. The hydrolysis and redox reactions that may occur in the carboxylic, ether and amide group may lead to aldehyde, alcohol, amine, phenyl derivatives as possible products of degradation.
Like nateglinide and pioglitazone, repaglinide would also be very prone to hydrolysis. To avoid its degradation, contact with moisture should be avoided by employing the measures discussed above.

It has been demonstrated the based on the structures of the following drugs, they are prone to degradation through hydrolysis and redox reactions. The degradation of pharmaceutical products has potential adverse effects which include loss of active ingredient, increase in the concentration of active, alteration in bioavailability, loss of content uniformity, decline in microbiological status, loss of pharmaceutical elegance and patient acceptability, formation of degradation products, loss of package integrity, reduction of label quality, and modification of any factor of functional relevance (Rhodes, 2000) therefore, measures should be considered in the manufacture, packaging and storage of these products. In the manufacture of drugs, oxidation can be prevented by filling out ampoules with oxidation-prone drugs under nitrogen (Rhodes, 2000). Moreover, the moisture content of the raw materials as well as the pharmaceutical products should be kept only at the required levels to prevent its hydrolysis. For packaging and storage, airtight bottles should always be ensured to prevent redox reactions to occur and dessicants should be placed with the products to prevent moisture and in turn, hydrolysis of the products. 

The adverse effects that may be caused by the degradation of pharmaceuticals are not something which can be taken lightly. It can lead to serious repercussions that will affect both the manufacturers and most especially the consumerspatients which are the end users of the product. Thus, it is very important to study the structures of pharmaceuticals and correlate it with drug stability to be able to avoid its degradation, hence, such adverse effects.

The central dogma of molecular biology explains the mechanism by which traits are transferred and preserved from generation to generation. Three important processes are involved in the central dogma, and these are composed of the following replication, transcription, and translation. Replication, the first step in the unidirectional process, requires the participation of primosomes in order to properly unwound, prime, and replicate the double-stranded DNA (deoxyribonucleic acid). This journal article investigates the molecular activities during DNA replication using bacteriophage T4 primosome and offers possible models of primosome behavior. The findings are also compared with the activity of bacteriophage T7 in order to assess the various helicase-primase properties of primosomes.

Background
A bacteriophage is a virus that infects bacterial cells. Replication, on the other hand, is the process wherein the double-stranded DNA is separated into single strands and each single strand is then replicated through the help of certain enzymes. In this study, bacteriophage T4  primosome was used to investigate the activity during DNA replication. The T4 primosome is composed of a hexameric helicase (gp41) and an oligomeric primase (gp 61) where the former is directly involved in the separation of the two strands in the leading strand of the DNA while the latter participates in the synthesis of primers in the lagging strand. The leading strand of the DNA has the 5 to 3 direction while the lagging strand proceeds in the 3 to 5 direction, which allows the production of Okazaki fragments (approximately 1 kilobase segments of the unwound DNA).

Usage of the T4 primosome results in the formulation of three possible models of DNA replication. Figure 1 reveals these models. The first models states that the helicase, the enzyme that catalyzes the separation of the double-stranded DNA, hinders the production of a new primer. The second model states that some primase, enzyme catalyzing the priming of the DNA, dissociate from the helicase in order to produce new primers. Lastly, the third model shows that the primosome remains attached to the DNA and the unwound segment forms a loop once the primer is transferred. Consequently, it can be deduced the the entire replication activity is stopped in the first model when the helicase pauses its activity while the second model allows a continuous replication events during the production of a new primer.

Fig. 1. The three models of T4 replisome activity during DNA replication
Key Experiments and Discussion 
In order to investigate DNA replication, a DNA hairpin situated between a magnetic bead and a glass surface was used. Video microscopy was used to record the activity of the DNA hairpin which was tracked and manipulated using the magnetic force. Bar and line graphs were used to easily present the experimental findings. Fig. 2 reveals the set-up of this in vitro model.
   
From the aforementioned set-up, the following findings were discovered the synthesis of the primers are dependent on the concentration of the ribonucleoside triphosphates (rNTPs) stopping of the T4 primosome is not significantly related to primer production and must only be a function of DNA stability disassembling of the primosome can happen during the synthesis of the primer and loops can really be formed during priming. Formation of loops is found to be a new mechanism that enables the  prevention of primase dissociation.Consequently, synthesis and utilization of primers is said to be a stochastic process that involves independent primer formation and helicase application. However, a different scenario was determined for T7 primosome because it allows the pausing of the entire replication process to allow the primer synthesis. Thus, results from this study shows that different helicase-primase activities co-exist in nature in order to favor maximum efficiency of the DNA replication process.     
   
Fig. 2. Synthesis of primer and helicase activity as observed using experimental set-up. (a). The arrangement of the DNA hairpin and magnet, (b) graphical representation of the gp41 helicase activity (green line) and wild-type primosome (red line), (c)features of hairpin reannealing, (d) frequency of experimental replication processes (Manosas et al., 2009).

Solar Energy, Our New Best Friend

During this time of shortage in affordable fuels, the public should be aware of the next possible solution on this circumstance. But what could be the best energy alternative The answer is simple. Lets start with the basics.

First of all, we need to think of the most abundant energy source available in our planet  and that is solar energy.

A second point we need to consider is the advantages and the disadvantages of the favored alternative. The good thing about solar energy is that it is for free. Of course it might cost in the beginning for we need generators and power plants. But these will be beneficial in the long run for it is everlasting. More or less, we receive 1000 watts per square meter of power while the sun is up. We can capture most of the energy in the form of heat, and then the heat would be used to drive a steam powered generator which is a solar thermal power plant. It uses a parabolic mirror array to focus the energy on a point making it extremely hot. Solar thermal power plants can run 247 because they can store the heat in liquefied salt. A mirror array that is three square kilometers in area can provide the same base load (constant) power supply as a coal fired power plant. As long as there is a sun, we can use this alternative.

But what if the sun does not shine This is the problem that we need to face for the solar power systems require the suns heat to generate energy. But lets not panic, No sun for the entire day doesnt mean no energy at all. Aside from the implanted liquefied salt in the thermal power plant, we can also rely to hybrid generator system. When the sun fails to appear, the hybrid generators will provide electrical energy in battery systems from varied sources.

A third point to remember is the main use of fuel in our society. Mainly, the oil has played a large role in empowering our vehicles since the 1950s. Today, the promotions of electric automobiles are highly approved by the government. Why Because it works like the usual and they do not cause pollution.

The DOE is still studying the growth and advancement that this particular alternative can bring. Surely we will adjust to the new way of using our automobiles and electric consumption but solar energy is still the best energy alternative so far.  Aside from its abundance and affordability, it is also environmental friendly and very convenient.

Weekly Summary Assignment in Chemistry

Why does a pressure cooker cook your food more quickly
Pressure cooker is capable of speeding up cooking by raising temperature by as much as 257 degrees Fahrenheit more by trapping much heat inside the cooker than the usual method. It uses trapped steam that builds up pressure to cook the food inside. Steam pressure hastens the release of heat in the air therefore saving time in cooking food.

Why do oil and water not mix Why can detergents and soaps force them to mix
Oil and water does not mix because of the factors that make them different from each other. First the two of them is known as immiscible or unlikely to mix because of their molecules and densities. Oil is much heavier and obviously less fluid than water so it tends to sink down while the water floats above it. Water has slightly polar molecule while oil has not. Soap is a chemical that is both polar and non polar so it tends to be a binder for the two molecules to attached at each end of the soap molecule so with the help of it and detergents one can make a way to mix them together.
Discuss the steps required to dissolve a solute into a solvent.

What changes must occur in the solute
For a solute to be dissolved in a solvent its particles or molecules has to gradually break into smaller pieces to combine with the particles of a solvent.

What changes must occur in the solvent
The molecules of the solvent will then start to move out or expand to make room for the new molecules. Once they combine the solute will evenly spread out on the solvent.
c) How can we predict if a solute will dissolve in a selected solvent
   
For us to predict if a solute will dissolve in a selected solvent, we have to determine the solubility rate or if they are miscible. These involved the saturation rate, solubility rate and specific chemical component of the solute to be dissolved in a solvent.

Why do oil and water not mix Why can detergents and soaps force them to mix

An old saying says that water and oil do not mix. Although these two compounds are both liquid, they do not blend.  When oil and water are put together in the same container, the oil immediately separates itself from the water and floats in the surface of the water, forming a glob or bead. Even vigorous stirring or shaking cannot mix them. The reason for this is that water and oil have different structure. Water is polar molecule its hydrogen component overwhelms the oxygen that charges its ion. On the other hand, oil is non-polar it is not charged. It consists of many C-H bonds that make it hydrophobic or water-fearing. Base on the scientific principle that like dissolves like, which means polar molecule dissolves polar molecule and non-polar dissolves non-polar, water cannot dissolve oil, or vice versa. There is no interaction between the two compounds because the molecule of water cannot form a bond with the molecules of the oil therefore, they do not mix.

Although water and oil differ in their ionic charge, they can be mixed with the addition of soap. Soap, commonly used in cleaning away dirt and grease that cannot be removed by plain water, has two unlike ends. Its one end is polar or hydrophilic, which is water-loving and dissolves in water on the other end is non-polar or hydrophobic, which avoids water but can dissolve non-polar molecules. When soap is added in oil with water, the polar end of the soaps molecule interacts and forms a bond with water molecule. This interaction creates an aggregation or clustering of   molecules called micelle. A micelle is a cluster of many soap molecules that bond together in a spherical shape wherein the hydrophilic heads are exposed outside while their non-polar tails, which do not interact with water, are inside. Since these tails attract non-polar molecules, the oil molecules are enclosed and dissolved inside the micelle. When water dissolves the soap, the oil within the micelle mixes with the water.

Dissolving Solutes in Solvents

In a laboratory setting, in order to make a homogeneous solution, you add the solute in small increments to the solvent, with thorough stirring or agitation of the mixture in each time until the solute is no longer distinguishable from the solvent or until a small amount of undissolved solute remains at the bottom after mixing. Heat may be applied to the solution to speed up the dissolution of the solute, although one risks supersaturating the solution when heat is used.
   
The molecules making up the solute are expected to disperse at a uniform manner throughout the solvent so a homogeneous solution is formed. Now, for this to happen the interactions between molecules (called intermolecular forces of attraction, or IMF, the strength of which depends on the amount of energy  contained  in the arrangement of the molecules by virtue of IMFs) binding them together to form the solid or liquid solute must be broken, so that the molecules are free to disperse. Additionally, for ionic solutes and electrolytes like sodium chloride dissolved in solvents like water, the ionic bond, which has an associated bond energy, is broken along with the IMFs. Thus two things can be said to happen to the solute when it dissolves (1) its spatial arrangement in the solution becomes random, or disordered and (2) its energy decreases. The same thing can be said for the solvent its IMFs get broken, and so it becomes more disordered and its energy decreases upon addition of the solute.
   
All substances dissolve in a given solvent to a particular extent, which is quantified and tabulated in chemistry books and manuals. Ionic compounds and electrolytes are expected to dissolve almost completely in solutions with water as the solvent. Solutes with weak IMFs are likely to dissolve in solution, and solvents with weak IMFs favor the dissolution of solutes. Also, strong interactions between solute and solvent molecules lead to good dissolution.

The chemical stability of a drug in the desired dosage form is of great importance, since therapeutic problems may result from poor drug stability. The net result of drug instability is that the patient does not receive the proper dose of the active drug entity, and therefore, the full therapeutic effect of the drug is not realised. Additionally, drug decomposition may yield toxic by-products which may endanger the patient.
The industrial pharmacistpharmaceutical chemist must choose dosage form excipients and storage conditions that result in an acceptable fraction (generally 90-95 or greater) of the drug being present for an acceptable length of time. The hospital or retail pharmacist must observe the manufacturers storage recommendations. Heshe must also be aware of the types of degradation that a particular drug is subject to since drug products are frequently re-packaged at the time of dispensing.

Hydrolysis of a drug entity can be a major factor in the instability of solutions. Aspirin, for example, undergoes hydrolysis with the resultant degradation products being salicylic acid and acetic acid. The rate of this reaction is said to be second order, since it is dependent not only upon the aspirin concentration, but upon solution pH (i.e. the hydronium ion concentration at solution pH values less than approximately 2.5 or the concentration of hydroxyl ion at solution pH values greater than approximately 7.0). At pH  7.5, the rate expression for the hydrolysis of aspirin may be written

EMBED ChemDraw.Document.4.5 
where,
A  the concentration of aspirinOH-  the hydroxyl ion concentrationK  the second order rate constantt  time
If the solution is buffered so that the hydroxyl ion concentration remains essentially constant, the rate expression may be rewritten as

EMBED ChemDraw.Document.4.5 
where,
C  the unchanging hydroxyl ion concentration
Since two constants can always be combined into one constant, the above expression is equal to

 EMBED ChemDraw.Document.4.5 
where,
Kapp  KC
From the above equation, it can be seen that the degradation of aspirin in a solution buffered at pH  7.5 will follow first order kinetics that is, the reaction will appear to be a first order reaction, dependent only on the concentration of one reactant i.e. aspirin.
The integrated form of a first order rate expression is
In At  In Ao - Kappt
where,
At  the amount of drug remaining at time  t Ao  the amount of drug initially present Kapp  the apparent first order rate constantt  time of sampling
This equation is of the form
y  mx  c
where,
m  the slope of the line c  the y- intercept
For the hydrolysis of aspirin in buffered solution (pH  7.5), a semi-log plot of the aspirin concentration remaining versus time should yield a straight line with a negative slope equal to -Kapp.
 INCLUDEPICTURE httppharmlabs.unc.edukineticsexcel1.gif  MERGEFORMATINET

The experimentally determined first order rate constant (Kapp) can be related to the true second order rate constant by the expression

Kapp  KOH-
The pseudo first order degradation of aspirin in a solution buffered at pH  7.5 can be followed by measuring the increasing concentration of salicylic acid spectrophotometrically.
One mole of salicylic acid is produced when one mole of aspirin degrades so, using the ratio of the molecular weights of aspirin to salicylic acid, one can determine the weight of aspirin degraded for each mg of salicylic acid produced.

EMBED ChemDraw.Document.4.5 
Thus, each milligram of salicylic acid present represents the degradation of 1.304 milligrams of aspirin. Since the amount of aspirin initially present is known, and since the amount of aspirin which has degraded can be determined, the amount of aspirin remaining can be calculated.
When a new drug product is being formulated, it is desirable to determine the stability of the drug entity in the drug product so that a shelf-life or expiration date may be assigned to the product. The shelf-life is the length of time required for the product potency to be reduced to some percentage of its original value. For most products, this is the T90 or time at which the product retains 90 of its original potency. Although the drugs stability at room temperature is of primary interest, a stability study at room temperature would take too long to be useful as a screening procedure for new formulations. Therefore, such screening studies are conducted at elevated temperatures in accordance with the Arrhenius equation

Kapp    Ae-EaRT
where, Kapp  the apparent rate constant for the reaction A  the frequency factor Ea  the activation energy for the reaction R  the gas constant (8.31441 J K-1 mol-1) T  absolute temperature (degrees Kelvin)
The Arrhenius equation can be rewritten as

 EMBED ChemDraw.Document.4.5 
Again, an equation of the form y  mx  c is generated, indicating that a semi-log plot of Kapp versus the reciprocal of the absolute temperature (i.e. 1T) should yield a straight line with a negative slope equal to -EaR. This line can be extrapolated to the value of 1T that corresponds to room temperature and the predicted rate constant for the reaction at room temperature can be taken from the y-axis.

 INCLUDEPICTURE httppharmlabs.unc.edukineticsexcel2.gif  MERGEFORMATINET
Although the degradation of aspirin in a solution buffered at pH  7.5 occurs too slowly at room temperature to be adequately studied during one laboratory period, the reaction proceeds rapidly at temperatures of 50 C and above. The reaction will be conducted at approximately 55 C, 60 C, and 65 C.

LEARNING OBJECTIVES
Upon completion of this exercise, you should be able to
Describe the rationale and techniques involved in accelerated stability testing. Explain how data at elevated temperatures is related to stability of the product at room temperature.
Differentiate between zero, first, and second order reactions and reactions rates.
Given drug degradation data for a compound, and the first order rate equation, construct an Arrhenius plot and determine
the activation energy for the degradation reaction.
the first order rate constant for the degradation reaction at 25 C.
an appropriate shelf-life for the product (usually T90 at 25 C).

Measurement of Surface

The surface of a liquid has a tendency to contract to the minimum area possible. The contractile force is referred to as surface tension. Surfactants (surface active agents) are solutes that decrease the surface tension of solutions. Surfactants may be referred to as amphiphiles, they contain an appropriate balance of hydrophobic and hydrophilic regions, therefore have affinity for both polar and non-polar solvents. It is this property that allows them to be absorbed at interfaces. Surfactants are important in pharmaceutical science as they are used as emulsifying agents, solubilising agents, foaming or anti-foaming agents, flocculants, deflocculants and detergents. You will be given more details about these agents in your Physical Pharmaceutics lectures. There are a number of standard ways of measuring surface tension in this experiment you will investigate two standard methods. Students are to work in groups of two - four.
 Measurement of Surface Tension - Surfactant Properties

Experiment 1
Drop Weight Method
If a drop of liquid forms slowly on the surface of a clean, vertical glass capillary, we can show that the mass of the drop is proportional to the surface tension. This is shown by Tates equation
mg  2prg
m  mass of drop (kg) g  gravitational constant (9.8ms-2) r  radius of tube (m) g  surface tension in Nm-1. The radius of the tube will influence the volume of the drop that forms. Unfortunately, ideal drops do not form hence a correction factor to account for the volume of the drop should be used.
The first experiment you will perform is a very simple assessment of how measurement of the mass of drops of liquid, can be used to investigate surface properties of drops. Although this is a very simple experiment, extreme care must be taken in measuring the correct number of drops and recording their masses accurately, otherwise meaningful results will not be obtained.
Method

You are supplied with a series of liquids, a glass beaker, a reservoir and tap arrangement that allows you to release solutions drop by drop. The liquids are distilled water and various concentrations of sodium chloride and cetrimide. You are required to measure the average mass of one drop of each of the liquids.
Make sure you are familiar with how to set the apparatus up to deliver one drop at a time.
1. Place the beaker on a clean, tarred balance and record the mass of the empty beaker.
2. Carefully place 20 drops of one solution into the beaker and re-weigh it.
3. Subtract the mass of the empty beaker to obtain the mass of the 20 drops of liquid.
4. Divide the mass obtained in part 3 by 20 to determine the average mass of 1 drop.
5. Without emptying the beaker, add 20 drops of a second liquid. Subtract from this, the mass recorded in part 2, to obtain the mass of 20 drops of this new solution.
6. Continue in this manner until you have recorded the average mass of 1 drop of each of the liquids supplied.
(NB. If you accidentally add more drops to the beaker this can be accounted for when you take the average mass of the drops ie if you have added 21 drops, divide the total mass by 21 instead of 20.)
Results
Mass of 20 drops distilled water  1.238    Average Mass of 1 drop  0.0619
Table Showing Mass of Drops of NaCl Solutions
Conc NaCl510152025Av. Mass of 1 drop0.072950.07570.078450.08100.08445Table Showing Mass of Drops of Cetrimide Solutions
Conc Cetrimide0.0050.0100.0150.020.0400.0600.080Av. Mass of 1 drop0.07070.06410.05420.0440.03580.03270.0296
Plot a graph of  concentration NaCl and Cetrimide against mass of one drop. Ensure the graph is fully labelled and attach it to your report. The concentration of the solutions is plotted on the same x-axis, you will need to have 2 separate scales, 1 for concentration of cetrimide and 1 for concentration of NaCl. Mass of the drops in grams is plotted on the y-axis.

Clearly label the critical micelle concentration on the graph.

iii) Briefly explain here what a micelle is
Micelle is a globule of molecules mixed in water wherein the hydrophilic part will be buried in the surface of the water and the hydrophobic part will be pointed at the air above resulting in reduced surface tension. The water loving and the water hating parts of the molecule will orient themselves according to their favorite interaction with the surrounding solvent. A critical micelle concentration is a concentration at which the molecules of a surfactant will produce micelles there will an inflexion point on the graph as the concentration crosses the critical micelle concentration (White, 1972).
iv) Calculate the surface tension of i) 10 NaCl solution and ii) 0.02 cetrimide solution.
Use the equation     mg  2prg     Assume r  0.0022m
surface tension of 10 NaCl solution  g                                       0.054 Nm-1

surface tension of 0.02 cetrimide solution  g                                      0.031 Nm-1

v) Briefly explain what your results tell you about the nature of NaCl and cetrimide.
For a sodium chloride solution, the surface tension will increase linearly. For a concentration of 10 of NaCl, the average mass of one drop increases resulting in increase surface tension. Whereas, the addition of 0.02 of cetrimide lowers the average mass of one drop of water, resulting in reduced surface tension. Cetrimide here acts a surfactant and will bury their hydro-phillic part in the water and the hydro-phobic part will be pointed towards the air above. As the water-hating parts of the molecule will not bond together to each other strongly so the surface tension will be reduced (Gennes et al, 2003).

Experiment 2. Capillary Rise Method
This is an alternative method by which surface tension of liquids may be measured. The surface tension of a liquid is proportional to the height to which the liquid will rise in a narrow capillary, as shown in the equation below
g  hrgr  2
Where g  surface tension (Nm-1) h  height of liquid (m) r   density of liquid (kg m-3) g  gravitational constant (9.8ms-2) r  radius of curvature of meniscus (m).
NB. In this experiment you must be very careful to convert to the correct units throughout.

Method
1. Half fill 2 medium-sized weighing boats, 1 with distilled water and 1 with 0.08 cetrimide.

2. Take 1 capillary tube and place it vertically into the distilled water. Once the liquid has risen up the tube, place your finger over the end of the tube to seal it, remove it from the vessel and measure the height to which the liquid has risen.

3. Drain the contents of the tube, by placing the end of the tube onto tissue paper.

4. Place the same tube into the 0.08 cetrimide, repeating the above procedure, measure the height to which the cetrimide rises. Discard the tube once it has been used in the cetrimide. Note that you must take the measurement for distilled water first, take care not to get any cetrimide into the distilled water.

5. Repeat the entire procedure using 4 more capillary tubes.
Results
Heights of liquids in tubes in metres
Tube 1Tube 2Tube 3Tube 4Tube 5Average Height Distilled Water0.00270.00280.00260.00290.00260.002720.08 Cetrimide0.00240.00250.00260.00200.00240.00238

i) Calculate the surface tension of 0.08 cetrimide.
Use the equation    g  hrgr  2
Assume the density of the solution is 1g cm-3 and the radius r  0.002m.
( 1g cm-3  1000 Kg m-3
surface tension of 0.08 cetrimide  g    0.00238 x 1000 x 9.8 x .0022  0.023 Nm-1

ii) On average, which of the two liquids rose to the greater height in the capillary tubes
Distilled Water rose to greater height.

iii) What is your explanation for this
The distilled water rose to a greater height than with cetrimide. This shows that the surface tension with cetrimide has dropped as the surface tension of a liquid is proportional to the height to which the liquid will rise in a narrow capillary.

iv)Why does placing the tip of the tube containing the liquid onto the tissue paper cause the liquid to drain out of the tube

Surface tension is in actual a property of liquids interface with another medium. Therefore, the surface tension between liquid - air and between liquid and any other material will be different. The surface tension between liquid and air will be greater than the surface tension between air and a material such as a tissue paper. Tissue papers will absorb through capillarity. As all forces are not going to balance for the liquid and tissue paper interface which will result in the flow of the liquid (Seddon and Templer, 1995).

So far, we have covered the importance of the three phases of water in shaping the surface of the planet, as well as examples of homogeneous and heterogeneous mixtures found in the workplace.
   
Water, as Ive discussed before, exists in one or a combination of three phases in nature, all of which have an effect on the surface of the planet. During wintertime, relatively small bodies of water turn into a solid white crust, thanks to the solidification of the liquid water into ice. The solid ice floats atop warmer water, as a consequence of its lower density compared to the liquid. This property allows for life to thrive under water during winter. The solidification of water to ice also shapes the planets surface via the freeze-thaw cycle, where during cold weather the trapped water in rocks turn to ice, which expands and, occupying more volume than water, pushes the constituents of the rock apart. The ice melts when it gets warmer, then solidifies back in the cold. This cycle tears the rock apart so that in time it is reduced to smaller pieces, which could be blown by the wind, pushed by running water or roll down due to gravity so that the surface features of the planet changes. The vaporization of liquid water to gaseous vapor and into liquid or solid also plays a role in shaping the earth, via the water cycle. The liquid precipitation, in the form of rain, cuts channels through rocks and soil as it flows to rivers, lakes and oceans, causing depressions on the surface that could in time be permanently filled up with water to make new bodies of water. Solid precipitation, like hail, destroys standing structures, clearing the land so that it can be acted on by the elements which could further shape it.
   
Many examples of homogeneous and heterogeneous mixtures can be found in the workplace, as well as everyday life. The very air we breathe is itself a heterogeneous gaseous mixture, composed of a more or less fixed amount of nitrogen, oxygen and other gases, combined with an amount of airborne particles (or particulate matter), the exact amount and distribution of which depends on the time of day and where you are in the city. The cleaning agent of water, bleach and detergent used by maintenance when wiping floors and windows is an example of a homogeneous liquid solution, as this solution contains a definite proportion of components which remains constant regardless of the region of the bucket the solution is taken from, assuming of course that we are talking of the solution prepared on that day. Commercial alcohol is also a homogeneous liquid solution, composed, as we all could see from the label, of 70 alcohol and 30 water. Finally, the donuts we eat at work can be said to be a heterogeneous solid solution, composed of homogeneous baked dough, coated in sugar and possibly sprinkled with other things, which are not distributed equally over the entirety of the donut.

Periodic Nature and Properties of Atoms and Elements

Mandeleev (1834-1907) is accredited to have successfully discovered laws governing the periodic nature of atoms and elements in the 1860s. A chemical element refers to the simplest chemical substance that cannot be broken down chemically with a distinct number of protons (atomic number) whereas an atom refers to the smallest particle of an element which has the same basic chemical properties to its element. Mendeleev discovered that similar chemical properties were exhibited by elements when arranged in order of their increasing atomic weight (nowadays periods and groups) and he termed this trend as periodicity (Spronsen, 1969).
                       
Properties of elements in relation to their atomic weights
Rowsperiods of the periodic table consist of elements with the same quantum number in the outermost orbital whereas columnsgroups consist of elements with the same electronic configuration in the outermost orbital. Across the period, the force exerted upon the outermost electrons increases with an increase of atomic number because there are more protons in the nucleus. In contrast, downward the group, the force decreases because of the shielding effect exerted by lower energy levels on the nucleus. Hence, the atomic radius increases down the group compared to a decrease across the period. For instance, lithium and fluorine are in the same period whereby Lithium has three protons compared to nine protons for Fluorine. Because of higher nuclear charge in Fluorine than in Lithium, the outermost electronsshells are strongly bound to the nucleus than in Lithium which renders Lithium atom to have a large atomic radius than the former even though it has fewer protons. In another other case, Fluorine and Chlorine are in the same group but the Chlorine has a larger atomic radius due to an increased number of protons (and shells) than Flourine. These two trends of atomic radius across and down the group determine the properties of elements to a large extent (Wetzel, 1993).
   
The second property of atoms and elements is the ionization energy which refers to the amount of energy required to remove an electron from a gaseous atom in its ground state (Ibid, 1993). With a decrease in atomic radius across the period, the ionization energy increases whereas with an increase in atomic radius down the group, the ionization energy decreases. Outermost electrons are held more strongly to the nucleus across the period than down the group. This explains the difference in relative amounts of ionization energy required for elements across the period and down the group. Electronic affinity is the third property which refers to the energy releasedabsorbed when an electron is added to a neutral, gaseous atom (Ibid, 1993). It also depends on the atomic radius down or across the group whereby reactions are more exothermic across the period because the electrons are tightly bound- in contrast to movement down the group. Fourth, electronegativity represents the relative attraction of electrons by the nucleus of a particular atom in a chemical bond and its dependant on electron affinity as well as ionization energy. It increases and decreases across the period and down the group respectively.
   
Wetzel (1993) in his work sates that the outermost electronic shells of noble gases (Helium, Neon etc) are completely occupied hence they cannot attract andor lose electron(s) are chemically inert. On the other hand, alkali metals (Lithium, Sodium etc) consist of one valence electron in the outermost shells whereas halogens have seven valence electrons. Therefore alkali metals have high affinity, are easily ionized, and highly reactive because they lose only one electron to acquire a stable state. The same case applies to halogens (Fluorine, Chlorine etc) which need only one electron to fill up the outermost shell and acquire a stable state. Ionization energy of halogens is therefore high with respect to their relatively small atomic radius besides their high affinity.

Chemistry and Society

Chemistry, as the branch of science dealing with the study and analysis of the composition of natural substances is a very crucial subject which the society would not do without in everyday life. From the moment an individual is born, chemical substances or their combinations are used to preserve life and aid in life development.

Every day I wake up but before commencing on my daily routine I have to ensure my hygiene and personal cleanliness. I take a bath using soap manufactured because of chemical knowledge of substances like cetyl alcohol, glycerine and propylene compounds. Without chemistry, the sole existence of these substances or their effects would not be known. The society depends on the knowledge of chemistry for the availability of items we cannot do without on a daily basis. Things like beauty products, soaps, toothpaste, medicines, manufactured foodstuffs and electric batteries that run our watches, calculators, television and other remote controllers as well as advanced health accessories like artificial pacemakers and hearing aids (Myers, 2003).

Alcohols, ethers, carboxylic and many other organic chemical compounds whose functional group contain carbon and oxygen also find extensive use in everyday life. The foods we eat containing starches, sugars vitamins and proteins exist because of the knowledge of organic chemistry. Fuel substances ranging from firewood and charcoal, petroleum products for home use, automobiles and industry are also a part of organic chemistry. The pharmaceutical industry, forever ensuring our protection from germs, infections and diseases is purely based on chemistry. As a matter of fact, the society cannot do without chemistry, life would be so unsystematic.

To benefit from chemistry, exactness is necessary depending on the scale and nature of chemical substances being measured. There are two categories of measurement accuracy and precision. Accuracy measurements are done nearest to the intended target because achieving the exact target would not be possible or would be too unnecessarily tedious under the circumstances. For example in the mixing of small quantities of liquid chemical substances, it would virtually be impossible to achieve measurements to the exact milliliter as some of it would still remain in the measurement apparatus (Myers, 2003).

Precision measurements are repeatable because reaching a distinct value is possible and can be repeated again and again. Precision measurements are so because they are described in terms of units, like length, weight and so on. However, the level of precision reached depends on the sensitivity of the measuring equipment used. If, for example a ruler puts the length of a steel rod at 7.91 centimeters, a more exact instrument would put it at 7.899 centimeters.

The society depends on all these measurements in the provision of their everyday supplies like gasoline, soft drinks, personal care accessories like soap and so many others. If an individual is buying a kilogram of beef, it is, according to the standards of the trade, to get exactly one thousand grams. It is therefore understandable to carry home the nearest value acceptable as a kilogram of beef. On the other hand, pharmaceutical products need more exactness in the balancing of their composition. A buyer of, say tablets of aspirin, will expect that the composition was done to a repeatable exact measurement so that it does not bring about undesirable side effects (Moore, Lngley, 2008). In everyday life, I depend on accuracy while filling my gasoline tank at the service station and precision while buying my medical provisions. In the measurement of liquid substances like drinking water, coffee and tea and some basic quantities like the amount of sugar to put in a teacup or the weight of salt to put in one serving are all measures of accuracy. 

The United States of America belongs to one of the most powerful and largest countries in the world today. Every person from different countries dreamt of visiting or migrating to the United States of America because of its vast natural resources, state-of-the-art technology, grandeur of its sceneries and cultures and the famous histories it was known for. Though powerful it may seem, it still cannot escape the inevitable like the terrorists attacks on The World Trade Center in New York City and The Pentagon in Washington D.C. last September 11, 2001. From thereon, the government of the United States of America implemented drastic measures to combat terrorism attacks and focus on the ways on how to prevent such acts.
   
The government of the United States of Americas national threat level is elevated or yellow excluding domestic and international flights. For all domestic and international flights, the U.S. threat level is high or orange (Homeland Security, 2010). In the aftermath of the September 11, 2001 attacks, the U.S. Department of Homeland Security implemented a system called The Homeland Security Advisory System designed to guide the protective measures when specific information to a particular sector or geographic region is received. It combines threat information with vulnerability assessments and provides communications to public safety including officials and the public (Homeland Security, 2010). In this system, the elevated or yellow risk of terrorist attack provides significant increased surveillance of critical locations.

Coordinate emergency plans with nearby jurisdictions, assess further refinement of protective measures and implement contingency and emergency plans as appropriate. The high or orange risk of terrorist attack means high coordinate necessary security efforts with armed forces or law enforcement agencies. Take additional precautions at public events, prepare to work at an alternate site or with a dispersed work force and restrict access to essential personnel only (Homeland Security, 2010). The terrorists commonly used bombs in their terrorism attacks. In the historical September 11 attack, the U.S. officials agree that bombs or hijacked jets used as bombs are the most likely weapons to be used against America (USA TODAY, 2008).
   
The government of the United States of America should be constantly on guard against suspicious persons and activities that would impose danger to the nation. The implemented measures should be followed strictly especially the centralized national threat warning system for terrorist attack should be taken seriously and with dedication so as to warn the public on the possible onset of an attack. As a citizen, one should always maintain vigilance and awareness of what is happening not only in ones hometown but in the United States of America as well. These are the useful ways on how to guard ones life in the onset of terrorism attacks.

Theory and Introduction

The acid-neutralizing capacity of a water sample is measured by its Alkalinity. It is a cumulative property of the water sample and can only be explained in terms of specific substances. The alkalinity of water is primarily due to the carbonate, bicarbonate, and hydroxide content. Sometimes, borates, phosphates, silicates, or other bases also contribute to alkalinity. These alkaline substances play the role of a buffer in water against sudden changes in pH. Alkalinity is important as an indicator of a water bodys ability to resist pH change with the addition of acid or an accidental spill.

Alkalinity is primarily of two types, Total and Phenolphthalein Alkalinity.
Phenolphthalein alkalinity is present only when free carbon dioxide (CO2) is absent and therefore exists only when the pH exceeds 8.3. Phenolphthalein alkalinity should never be over half the total alkalinityotherwise, a caustic alkalinity is produced.

Total Alkalinity and Phenolphthalein Alkalinity are defined as follows
 EMBED Equation.3 

Determination
1.) Measure 100 mL of your sample into a 250 mL. Insert a bar magnet and place sample onto a stir plate.

2.) Note initial pH of the sample. If the pH is above 8.3 add several drops of phenolphthalein indicator. Titrate your sample with 0.02 N H2SO4 or HCl until the pH endpoint (color change) is reached. This is the phenolphthalein alkalinity. Record the total volume of acid needed to reach the endpoint.

3.) If pH is below 8.3, add a few drops of bromcresol green indicator. Titrate your sample with 0.02 N H2SO4 or HCl until the pH 4.5 endpoint (color changes from blue to yellow) is reached. Note the total volume of acid needed to reach the endpoint.

4.) The total alkalinity of the sample can be calculated using
Where A is the total volume in mL of the standard acid used  N is the normality of the standard acid used  50,000 is a conversion factor to change the normality into units of mg CaCO3L Analysis of Results (assuming all of the alkalinity is due to carbonate, bicarbonate, or hydroxide)

How the Phases of Water Affect the Planet

The fact that water exists in three phases  solid, liquid and gas  and that it exhibits a variety of properties when in any of these forms means a lot for the surface of the earth. Most familiar would be the behavior of bodies of water in wintertime the surface is covered in a sheet of ice ranging in thickness from a few inches in lakes to a couple of meters in larger bodies of water, which floats above the warmer liquid water.

Ice is less dense than water, so that it does not sink to the bottom as is the case for the solid phases of other materials, and the water solidifies not all at once but gradually, so that water that is not exposed to the cold air remains warm. This allows living organisms to thrive in winter and not to be frozen solid where they were on the onset of the chill. Another example of the influence of waters three phases on the face of the earth is the freeze-thaw cycle. On cold nights, the water trapped in rocks may turn to ice, which, due to its lower density, occupies a greater volume than liquid water, thus pushing the constituents of the rocks apart just a bit.

Repeating this creates a cycle that leads to the breaking up of large chunks of rock into smaller pieces, which could now be carried by running water and wind to other areas so that the minerals making up the rock is spread out to enrich the soil. Finally, water shapes the earths terrain when gaseous water vapor comes down in as precipitation as rain, the liquid water cuts channels along rocks and soil as it passes, making depressions on the surface and filling these up semi-permanently or permanently with water to make rivers and the like and as solid precipitation like hail, it can strike down structures like trees and vulnerable buildings, clearing up swaths of the surface to be acted on by the elements.

Homogeneous and Heterogeneous Mixtures in the Workplace

The term mixture connotes a physical combination of two or more substances in which each substance retains its identity (Stoker, 2007, p. 6). Mixtures can be classified as homogeneous and heterogeneous.  The former has uniform appearance and properties throughout whereas the latter consists of visibly different phases or parts, each having different properties (Stoker, 2007, p. 6). Every workplace abounds with examples of both types. Starting with concrete walls and cemented floors, both concrete and cement are heterogeneous mixtures (Welch, 2008).

Concrete is made up of cement, sand or gravel and water. Gravel in itself is a heterogeneous mixture. Next, wall paint consists of liquid solvent and solid pigments, making it another instance of heterogeneous mixtures (Welch, 2008). Wood used to make workplace furniture is also heterogeneous in nature (Stoker, 2007, p. 6). Steel, another constituent of several workplace items, is a homogeneous mixture.

Offices are incomplete without a stock of files and folders stuffed with printed and written papers. Paper and ink comprise another heterogeneous mixture in the workplace (Acro, 2002, p. 190). Black ink, however, in itself is an instance of homogeneous mixtures, as is the air employees breathe in the workplace (Acro, 2002, p. 190). Air is mainly made up of oxygen and nitrogen gases. Electrical brass wiring is used extensively in the workplace. Brass, an alloy of copper and zinc, is a homogeneous mixture.

Workplace refreshments like brewed coffee and unopened soft drinks are homogeneous mixtures, water with ice cubes and iced tea are heterogeneous mixtures (Shipman, Wilson,  Todd, 2007). Workplaces lined with indoor plants are furnished with another heterogeneous mixture in the form of soil. Carpets, curtains and cushions with multiple threads are also heterogeneous (Acro, 2002, p. 190). It would not be wrong to say that homogenous and heterogeneous mixtures together make a workplace. 

The geometry or shape of a molecule has a signifcant effect on the physical properties of the molecule. The chirality of carbon can determine its optical activity. Even if two compounds are of the same formula, one compound could be transparent the other opaque just because of a slight difference in geometry. The cis and trans configurations of fatty acids affect the melting point even if the fatty acids have similar formulas. The trans-fatty acids have a relatively high melting point and are likely to acculmulate and clog arteries as they stay in solid form (McMurry, 2003).

The geometry of a molecule also plays a vital role in determining if a chemical reaction will take place. For example, the Diels-Alder reaction requires the the diene to have the -bonded carbons in the cis configuration. Should the -bonded carbons be in the trans configuration, then the reaction process will be antarafacial highly unlikely to produce the desired cycloaddition product.

Carbon Compounds Organic Compounds

The nucleus consists of six protons and a number of neutrons that ranges between 2 and 14 depending on the carbons isotope. Six electrons surround the nucleus, two in the K-shell and four in the L-shell
(Carbon,  2010, p. 1).   

Since an L-shell needs eight electrons to become full, the carbon atom needs to fill its L-shell (valence shell) with additional four electrons from other atoms in order to become stable. Thus, a carbon atom can form various combinations of chemical bonds  Four single bonds two single and one double bond two double bonds or one single and one triple bond  
(Carbon, 2010,p.1).                                                                                                               

Name and Structure of two Hydrocarbons and one Biochemical MoleculesHydrocarbons     A hydrocarbon is an organic chemical compound that consists of only two elements, carbon and hydrogen
(Hydrocarbon,  2010, p.1).   
Methane (CH4). One carbon atom bonded to four hydrogen atoms with four single bonds ( Methane,  2010, p. 1).     
Ethylene (C2H4). Two carbon atoms bonded to each other with a double bond. Each atom is bonded to two hydrogen atoms with two single bonds ( Ethylene,  2010, p. 1).
Biochemicals     A biochemical is any type of chemical compounds that is  found in or having an effect on living organisms  ( Biochemical,  2010, p. 1).    
Glucose (C6H12O6). A chain of six carbon atoms connected together with single bonds. Atom 1 is bonded to one oxygen atom with a double bond, and to one hydrogen atom with a single bond. Atom 6 is bonded to two hydrogen atoms with two single bonds, and to one hydroxyl group (OH) with a single bond. Each of the middle four carbon atoms is bonded to one hydrogen atom and one hydroxyl group
(Glucose,2010,p.1Ophardt,2003,p.1).                                                                                                        
                
Carbon Is Said to Be Unique Because It Forms Nealy Limitless Number of Organic Compounds. How Is That PossibleStrong Ability to Form Covalent Bonds Since a carbon atom can receive additional four valence electrons, it has a strong ability to form an unlimited number of chemical compounds with different  chain, branched, ring, and three-dimensional structures  ( Carbon,  2010, p. 1). High Electronegativity ValueElectronegativity is important in chemical bonding because its  the relative ability of an atom to attract valence electrons  ( Carbon,  2010, p. 1). Carbon has a high electronegativity value (2.5), which is the sixth highest among all elements. Interestingly, carbon is more versatile than the element with the highest electronegativity value, fluorine, because the latters ability to attract valence electrons is so strong that it prevents flexibility in chemical bonding

Electrophilic Aromatic Iodination

The reaction was carried out by dissolving 1.01 g of vanillin in 20 ml ethanol (EtOH) in a 100 ml round bottom flask. The presence of alcohol in the reaction medium increases the selectivity and yield of the iodinated aromatic compound. 1.17 g of sodium iodide was then added to this mixture prior to cooling it in a water bath. 11 ml of aqueous sodium hypochlorite was added drop-wise using a separatory funnel while mixing the mixture for more than 10 minutes. Sodium hypochlorite was used to produce the iodinated aromatic compound with the presence of alcohol. 10 ml of sodium thiosulfate was then added to the mixture prior to the addition of HCl. The pH of the solution was checked occasionally during he addition of HCl.

The flask was left to cool down for 10 minutes and the product that precipitated was collected by vacuum filtration. The residue was washed well with ice cold water and a small amount of ethanol to ensure high yield.

The crude product was then placed in an Erlenmeyer flask and was heated upon addition of ethyl acetate. Heating dissolved the ethyl acetate. 6 ml of hot water was added gradually while heating until the mixtures became cloudy. 1ml of ethyl acetate was added to generate a clear coloured solution. The solution was left to cool down in an ice water bath for a few minute to ensure complete crystallization. The crystalline product was collected by vacuum filtration and was allowed to dry.

Data
The data for iodination is shown below
Mass, g yieldCrude product 1.70Purified product2.14
Results  Discussion
The aryl iodine precipitated at the bottom of the flask. 6 ml was the total volume of HCl used to make the solution acidic. The pH was measure to have a value of 2 which is very acidic. Upon addition of HCl  changed from pale yellow to reddish brown. The mass of the of the crude product collected using vacuum filtration is 1.70 grams and the mass of the purified product is 2.14 grams. The theoretical mass of the product (5-iodovanillin) is 1.85 g.

The boiling point observed was 180 oC as compared to the literature value of 183-185 o C. The actual boiling point of the solution is less than the literature value because of its water content which has lower boiling point than the product.

Atom economy is defined as the molecular weight of the desired product(s) (here 278.04 gram per mole for 5-iodovanillin) divided by that of the reactant(s) (here 152.15 gm per mol for vanillin). Therefore, in this experiment the atom economy is 182. In this experiment, 1.01 gm vanillin was used. This corresponds to 0.007 moles of vanillin. As one mole of vanillin can theoretically yield 1 mole of 5-iodovanillin therefore, in this experiment the theoretical yield of 5-iodovanillin is 0.007 mole, which is 1.85 grams. Hence theoretical yield of 5-iodovanillin is 1.85 gram.
Atom Economy   (Mass of Product Sum of Mass of Reactants)  100  182

The oxygen of (i) uses two electrons to abstract an acidic hydrogen. The single bond breaks and two electrons go to oxygen, forming a carbocation and acetic acid (ii). The carbocation is then attacked by the oxygen of the hydroxyl group of salicylic acid to form (iii). O-H bond breaks and two electrons go to oxygen forming the final product (iv).

1.    Why does aspirin dissolve in aqueous sodium hydrogen carbonate whereas the key contaminants do not
By dissolving sodium bicarbonate, the ionic strength of water increases. Sodium ions surround water molecules, preventing the water molecules from interacting with (and thereby dissolving) polar substances. This results in the polar substances (in this case, the impurities) to become less soluble and thus be easily filtered from the desired product. Conversely, the high ionic strength helps dissolve the partially-soluble acetylsalicylic acid in water. It is then possible to recrystallize the sample and expect a relatively higher purity.

1.    Explain the chemistry involved in this limit test.
The ferric chloride reacts with phenols and enols, producing a temporary or permanent coloration. Since the salicylic acid itself is a phenol, the ferric chloride test will yield a positive result. The intensity of the coloration is determined by the quantity of the enol or phenol in the sample. The greater the enol or phenol in the sample, the more intense the color. Should the intensity be greater than that of the standard solution, then the sample has a high concentration of salicylic acid which in turn indicates that only a very small amount of the target acetylsalicylic acid has be synthesized.

2.    Explain the presence of acetic acid in the standard solution.
Since it is a by-product of the synthesis of acetylsalicylic acid, the presence of trace amounts of acetic acid in the sample is likely. It could also result from the incomplete reaction of the salicylic acid with the anhydride. The anhydride was converted to acetic acid but did not react with the salicylic acid to form the target compound. Acetic acid is then added to the standard solution to control this particular variable.
3.    Discuss the results obtained with reference to the methods employed.
   
A yield of 71.2 was observed for the synthesis of the crude product. Loss was likely from the filtration process that followed after the product crystallized. It could also be due to the incomplete reaction of the anhydride and salicylic acid with phosphoric acid. Furthermore, the latter could explain why the melting point for the crude product was lower than expected.
   
The observed melting point for the crude product was much lower than the known melting point for acetylsalicylic acid. It is very plausible that this is due to the polymeric by-products mixed with the crude sample. The crude product contained impurities that had relatively low melting points and were of greater quantity than the target compound.
   
The recrystallized product yield was 23.3, much lower than the yield of the crude product. Since the crude product was subjected to purification process, the unwanted by-products were separated from the target compound thereby lowering the weight of the recrystallized sample. It is also plausible that some of the target product did not dissolve in the aqueous sodium carbonate solution because the ionic strength was not high enough to dissolve salicylic acid a compound only partially-soluble in water. Also, the recrystallization process was only allowed for a brief amount of time so it is likely that some of the product is still in the flask, not yet recystallized.
   
The recrystallized product was observed to have a melting point approximating that of pure acetylsalicylic acid. The slight deviation from the known melting could be due again to impurities. But since the polymeric by-products have been filtered from the sample, there should be only trace amounts left. The trace amounts could still melt at a lower temperature than the deisred product.

1) I suggest that a reorganization of the data in the table will make it a more efficient tool for determining the identity of unknown samples. Look carefully how you will rearrange the table.

The physical appearances were first categorized into color, physical features, and smell. The solubility was also divided into the different solvents and each solvent had 2 columns, one for whether the solid was soluble or insoluble, and the other for the features of the resulting solutionmixture. The latter includes whether the resulting solution changed color, or whether the solid formed a colloid-like mixture or just separated, as well as other features such as smell or notable dissolution times. The solids themselves were then arranged. First the solids were arranged with respect to color white being the first as it was the most common, followed by off-white, then red, yellow, and so on. The resulting color groups were then arranged by solubility by the order of the solvents. This arrangement was established to efficiently identify one of the given solutes once they were presented as unknown solids.

2) Explain why this rearrangement makes the tables easier to use as a tool in identifying the unknown samples.

The table was arranged with easy identification in mind, following a step-by-step elimination process that would give the desired results. This way, one does not need to check every single property of the unknown substance against the table, as this way it is possible to identify the substance in any of the process steps. The process flows from left to right, checking the properties of the unknown solid column after column. The first attribute that one notice when analyzing an unknown substance is its physical appearance, and color is one very striking physical feature, thus the first arrangement. For instance, if the substance is yellow, then one does not need to check the other properties to determine that the solid is Flores Martis. Thus the simple process of elimination is employed in this arrangement, and if the experiment is executed basing left-to-right arrangement of the columns, the table will prove to not only be an easy way to identify solids, but also a more efficient way.