Intermolecular Forces Essay

Intermolecular Forces Essay.

Intermolecular forces exist between independent particles, such as atoms, ions, or molecules. They can be forces of either attraction or repulsion. The amount of charge, how it is distributed, and the length of time that a charge distribution exists can affect the strength of intermolecular forces. And despite having variable force strengths, all intermolecular forces are considered weak compared to chemical bonds, or intramolecular forces. Chemical bonds are not only stronger; they are also more permanent.

The energy costs involved in breaking chemical bonds are much higher than ones needed to overcome intermolecular forces.

There are five types of intermolecular forces: ion-ion forces, ion-dipole forces, ion-induced dipole/dipole-induced dipole forces, dipole-dipole forces, and London dispersion forces. Generally, we expect ion-ion forces to be the strongest, followed by ion-dipole, dipole-dipole, and then London dispersion forces. Of course, many exceptions to this hierarchy of strength exist.

In order to properly differentiate between these forces, it is important to know what must be present in order for each interaction to occur.

Ion-ion forces only involve ions in mixtures of substances. Ion-ion forces can be either attractive (cation-anion) or repulsive (cation-cation/anion-anion) and the strength varies depending on charge and size. Ion-dipole forces occur in mixtures between ions and polar molecules. The anions gravitate toward positive regions of dipoles while the cations gravitate toward negative regions.

With dipoles, the strength of the forces depends upon the polarity of the molecule (or charge magnitude) and how compact the molecule is. If a molecule is more compact, there is better access to the center of charge and stronger attraction to its neighbors. Induced dipoles occur when nonpolar molecules come in the vicinity of polar or charged particles and become polar themselves. As an ion or dipole moves closer to the nonpolar molecule, a shift occurs in its electrons, throwing off its nonpolar symmetry and making it polar.

Depending on what produces this change, it will have either attractive ion-induced dipole or dipole-induced dipole forces. These may occur in pure substances or mixtures. Dipole-dipole forces may occur between the polar molecules of a pure substance, or between two different polar molecules. The positive regions of one dipole will attract the negative regions of another and vice versa. The dipoles tend to align in a way that increases the number of attractions and reduces the number of repulsions.

The strength of the force can vary with polarity: the more polar the molecules are, the more strongly they interact with each other. Hydrogen bonding is considered a special case of dipole-dipole interaction. While dipole-dipole forces are generally considered to be fairly weak, hydrogen bonding is unusually strong, especially in water. This particular type of bonding occurs when a hydrogen atom is involved in an extremely polar covalent bond, such as H-N, H-O, or H-F, and is attracted to the lone pair of a highly electronegative atom (either F, N, or O) on a separate molecule.

These may also occur in pure substances. The weakest of the intermolecular forces are the London dispersion forces. These forces occur between atoms or molecules of nonpolar substances and are present in both pure substances and mixtures. A way to predict the types of intermolecular forces present is by looking at the chemical formula, specifically whether the interacting species are polar or nonpolar. Ion-dipole forces occur between ions and polar molecules. Dipole-dipole forces (including hydrogen bonding) only occur between polar molecules.

Induced dipoles occur between polar and nonpolar molecules. If there were only nonpolar molecules, they would be London dispersion forces (but keep in mind that these forces also exist in every other kind of interaction). In the case of ion-ion forces, polarity does not matter in identifying forces, as it only involves ions and would be fairly obvious. Knowing what we do about intermolecular forces and their relative strengths, we can make a few assumptions about which forces would be present in different phases under standard conditions.

Being that solids are the most difficult to break apart, we would assume that the strongest intermolecular forces (ion-ion, hydrogen bonding) would be found within them. Liquids have a greater ability to flow because the intermolecular forces are weaker than in the solid phase, so we would assume that these would involve ion-dipole and induced dipole forces. We would also assume that the weakest intermolecular forces correspond to the gas phase, meaning dipole-dipole and London dispersion forces.

Intermolecular forces influence physical properties of each phase: gas, liquid, and solid. They can cause real gases to deviate from ideal gas behavior. They can also govern the motion of molecules; molecules in gases move constantly and randomly, they slide past each other freely in liquids, and vibrate in fixed positions in solids. The heats required to melt a solid (heat of fusion) and to vaporize a liquid (heat of vaporization) change depending on the strengths of the intermolecular forces. In liquids, water will form beads upon contact with waxed surfaces (e. . car hoods) because of the imbalance of how intermolecular forces act upon surface molecules and the symmetrical distribution of forces experienced by interior molecules.

So, the stronger the intermolecular forces, the larger the surface tension. Capillary action is another example of the effect of the imbalance of intermolecular forces. If the intermolecular interactions between the particles of a liquid and a solid are stronger than the intermolecular forces acting between the liquid’s own particles, the liquid near the walls of the solid will rise.

Other properties of liquids that can be affected by intermolecular forces are boiling point and critical temperature and pressure. In crystalline solids, the stronger the forces are, the more rigid the crystal is. This is because the stronger intermolecular forces in the solid fix the particles in place. Overall, understanding intermolecular forces is essential to understand gas, liquid, and solid phases, as well as the phase changes between them.

You may also be interested in the following: heptane intermolecular forces

Intermolecular Forces Essay

Starch, Glycogen and Cellulose Essay

Starch, Glycogen and Cellulose Essay.

A polysaccharide is a long chain of monosaccharide molecules, held by glycosidic bonds. They are usually not sweet in taste, insoluble in water and often do not produce crystals when water is taken out. Starch

Starch is a complex solid carbohydrate, consisting glucose molecules held together by glycosidic bonds. It is a storage polysaccharide. They can be found in fruits, seeds, roots and other parts of the plant. The monomer of starch is glucose. Therefore, starch molecules can be made by polymerisation reaction, where glucose molecules are joined together to form a long chain.

These starch molecules are held by glycosidic bonds. Uses of starch

* Forms parts of a cell wall * Energy storage * Can be digested by humans with amylase to make glucose for respiration * Plants use starch as stored energy for later use, breaking it down to glucose for respiration

Starch is a polysaccharide, so it has very large molecules. This means they are insoluble, so they are suitable for storage because they do not do osmosis, do not easily diffuse out of cells; is compact as a result of its glycosidic bonds’ angles giving it a coiled structure, making it possible for them to be stored in small places.

It is also made up of small sub-units of alpha-glucose, making it easier for enzymes (amylase) to break down the molecule for an efficient release of glucose for respiration.

Glycogen Glycogen is a highly branched polysaccharide which is the main form of storage in animals. It has a similar structure to starch, but glycogen has shorter chains. It is mostly stored in small granules in animals Glycogen structure is similar to the structure of starch. Therefore, it is a large molecule, making it insoluble so it is suitable for storage in animals. It is also compact because of its glycosidic bonds giving it its coiled structure, so they can be stored in small places. However, they are made up of smaller chains so they can be easily hydrolysed into alpha-glucose for more efficient respiration.

A molecule of glycogen is made up of hundreds of units of glucose, branching off every ten glucose molecules or more. These molecules are joined together by a condensation reaction, held by glycosidic bonds.

Cellulose Cellulose is a polysaccharide which is the main part of every plant tissue, consisting of long unbranched chains of glucose units which are linked. Cellulose differs from starch and glycogen as it has a straight, unbranched chain instead of a coiled chain. Apart from this, the major difference between cellulose and starch and glycogen is that instead of alpha-glucose monomers, there are beta-glucose monomers. This however causes major differences in the structure and function of the cellulose. This is mainly because of the reverse positions of the –H and –OH groups.

The –OH groups, instead of being below are above the ring. Therefore, every beta-glucose molecule must be rotated 180 degrees to molecule next to it, in order to form glycosidic bonds. This means that there is an alternation with –CH2OH group on every beta-glucose molecule, from being either above or below the chain. The cellulose molecules are grouped together, forming microfibrils, making them parallel to each other, so there are hydrogen bonds in between adjacent chains. The large numbers of hydrogen bonds still strengthen the cellulose, hence why it is good for structural purposes. Cellulose is important as they give the rigidity and strength of plant cells.

The bonds between the molecules are strong, making them hard to break down/digest. Also, cellulose cell walls prevent water entering by osmosis so they do not burst as they apply inward pressure to prevent any more water entering. Therefore, the plant cells become turgid. This helps maintain stems and leaves to be turgid so there is a lot of surface area for photosynthesis.

Starch, Glycogen and Cellulose Essay

Introduction to Organic Chemistry Essay

Introduction to Organic Chemistry Essay.

Amines are compounds composed of nitrogen atoms bearing alkyl or aromatic compounds. Amines undergo interesting reactions, one of which is with the reaction with nitrous acid producing an azo dye. In this study, the experiment focused on synthesizing an observing the physical properties of Sudan-1. Sudan-1 is of the most common dyes found in waxes, oils and in some food ingredients specifically curry and chilli powder.

Furthermore, this study aimed to understand the mechanism behind the synthesis of 1-phenylazo-2-naphtol. To be able to synthesize Sudan-1, preparation of phenyldiazonium chloride solution and β- naphthol solution were done.

Ingrain dyeing was also done in this experiment. The synthesis of Sudan-1 has a two-step reaction – diazotization and coupling reactions. Diazotization is the formation of diazonium salt, meanwhile, the coupling reaction took place when an activated aromatic compound, β-naphtol was reacted with the diazonium salt, benzene diazonium chloride, to form the azo compound known as the 1-phenylazo-2-naphthol. As a result, an orange-red precipitate was formed after series of reaction.

Hence, all the said objectives in this experiment were achieved.

Amines are compounds that are composed of a nitrogen atom bearing alkyl or aromatic groups. They are basic and nucleophilic because of their lone pair. They occur both in plants and animals. Amines produces some of the most interesting effects and of the common reaction of aminewith nitrous acid producing a dye[4]. Alizarin, for example is a red dye extracted from madder root used by Egyptians and Persians. However, in this experiment, it aimed to produce a dye commonly known as Sudan-1. Sudan-1 is a lysochrome with the chemical formula 1-phenylazo-2-naphthol. It is a powdered substance with an orange-red color.

This azo dye is most commonly found in waxes, oils, and also in some food coloring ingredients – curry powder and chili powder. However, the presence of Sudan-1 in most foods now is currently being banned because it has been classified to be carcinogenic. This experiment focused on synthesizing of 1-phenylazo-2-naphthol which is a two-step reaction. The first reaction is the reaction of aniline with nitrous acid, which is called diazotization and second, the reaction of diazonium salt and beta-naphtol to form azo dye which is the coupling reaction.

Figure 1 Diazotization Reaction of Aniline to Produce a Diazonium Salt Figure 1 Diazotization Reaction of Aniline to Produce a Diazonium Salt In diazotization reaction, there is a formation of diazonium salts. This reaction is made possible when a primary aromatic amine is treated with nitrous acid. Then in coupling reaction, the electrophilic substitution reaction of a diazonium salt with an activated aromatic ring formed a azo compound specifically an azo dye.[3] The main objective of this study was to be able to synthesize Sudan-1. Also, it aimed to characterize the azo dye with its most distinguishing physical properties. Furthermore, this experiment also aimed to understand the mechanism behind the synthesis of Sudan-1.

Figure 2 Coupling Reaction of Benzene Diazonium Chloride with β -Naphthol Figure 2 Coupling Reaction of Benzene Diazonium Chloride with β -Naphthol Aniline was reacted NaNO2 crystals under acidic condition using HCl in a cold temperature. The solution was done in a very cold temperature because the phenyldiazonium intermediate easily decomposes back to its aniline counterpart at a slightly high temperature; hence the temperature of the solution was maintained in an ice bath below 5°C.

Rock salt may also be added to the ice bath to maintain the temperature. However, in this experiment, no rock salts were added instead constant monitoring of the temperature was done. β-naphthol solution was used as a coupling reagent in synthesizing Sudan-1. In preparing β-naphthol solution, β-naphthol was dissolved in 5% of aqueous NaOH and was also cooled in an ice bath below 5°C, this was to avoid the decomposition of the compounds. The main reaction that occurred in the preparation of phenyldiazonium chloride solution was diazotization reaction. Diazotization is the reaction between a primary aromatic amine and nitrous acid at cold temperatures to diazonium salt compound.[2] Figure 1 below is the reaction exhibited by the phenyldiazonium chloride solution.

As this experiment aimed to synthesize Sudan-1, two steps are done. The first step would be the reaction of a primary aromatic amine to produce a diazonium salt as seen in Figure 1. The second step, then, is the reaction of the diazonium salt with a strongly activated aromatic syste,l known as coupling reactions. Azo coupling is the reaction between a diazonium compound and aniline, phenol or other aromatic compound which produces an azo compound.[5] In this experiment β-naphthol couples with the diazonium salt. Figure 2 below shows the coupling reaction of the benzene diazonium chloride with β-naphthol and having the product of Sudan-1. Furthermore, figure 3 below is the summary of reactions of the synthesis of Sudan-1 in this experiment. Figure 3 Summary of Reactions in Synthesizing Sudan-1

Figure 3 Summary of Reactions in Synthesizing Sudan-1

In this experiment, a filter paper was used to undergo ingrain dyeing. Ingrain dyeing is an irreversible chemical reaction of the diazonium salt solution and the activating aromatic solution. An orange-red filter paper was produced after such procedure. The presence of orange-red color in filter indicates the presence of the azo dye (see appendix for the orange-red filter paper produced). The Sudan dye is synthesized right in the spaces between the filter paper such that they are permanently trapped inside the fiber spaces of the filter paper.[2]

After mixing the phenyldiazonium chloride solution with the β-naphthol solution, an orange-red paste-like solution was formed. Furthermore, the mixed solution was also reacted at a temperature not exceeding 4˚C for 1-5 minutes. Afterwards, the mixture was also filtered was washed with several portions of water to filter the product, Sudan-1.

Recrystallization was also done when the filtrate was steamed bath after dissolving it with 95% hot ethanol. AS a result, orange-red crystals were formed which is the Sudan-1 product. The crystal appeared to be orange-red in color due to the N=N bond present in Sudan-1. The N=N is responsible for the absorption of

light thus reflecting a color which is orange-red. The structure of Sudan-1 is shown in Figure 4 below showing the N=N bond of the compound. The N=N is known as the chromophores which are responsible for the color. The –OH group attached in the structure is also responsible for enhancing the orange-red color. The –OH functional group is known as the auxochrome, which modifies the ability of the chromophore to absorb the light.[1]

Figure 4 Structure of Sudan-1

Azo-compounds, compounds with general formula Ar-N+=N-Ar-, are coupling products from the reaction of diazonium salts with amines. The general reaction pattern for Sudan synthesis first undergoes diazotization reaction and then coupling reaction with highly activated aromatic compounds. In this experiment, the diazotization reaction of aniline with NaNO2 and HCl yielded a diazonium salt, benzene diazonium chloride. Furthermore, the diazonium salt then underwent coupling reactions with an activated aromatic ring which is β-naphthol.

The coupling reaction yielded an azo compound which is most commonly known as the Sudan-1 with an IUPAC name of 1-phenylazo-2-naphthol. As a result of the reactions in this experiment, an orange-red color of solution was produced. This experiment aimed to understand the reactions that underwent to synthesize Sudan-1; as a result, figure 3 was the summary of reactions. As a physical result, orange-red colored crystals were produced representing the azo compound, Sudan-1. However, some minor errors will not be ignored in this experiment.

Some errors like human errors might have affected the results in yielding a pure azo compound. One human error, would be the measuring of the reagents used to yield the said product. Also, the misreading of some measurements may have also affected the results of this experiment. Also, some impurities in the chemicals used will also not be ignore, since this impurities may have led to a not so visible side reactions in the said experiment. After being said and done, all the said objectives in this experiment were met.

Introduction to Organic Chemistry Essay

Effects of Soil Ph on Radish Plants Growth Essay

Effects of Soil Ph on Radish Plants Growth Essay.

Background information:

the soil ph can have 2 different impacts on the growth of plant roots. First and most important is how it affects the concentration of nutrients present in the soil itself. This variable varies depending on the ph tendency, in particular, nutrients like phosphorous, potassium ,sulphur, calcium and magnesium tend to drastically decrease in more acidic ph conditions (<6.0), on the other hand iron, manganese, boron, copper and zinc tend to lack in alkaline enviroments (>7.5) [figure 1].

The importance of these types of nutrients varies depending on the species of plant, in this case radish tends to show higher concentrations of Potassium, Calcium, Magnesium, Copper, Manganese, Phosphorous and Sodium.

These all tend to grow in more alkali or neutral soil conditions rather than acidic as showed in figure

1. Another variable affected by a change in ph is the growth of microorganisms in the soil specifically affecting their respiration rate and the PLFA (phospholipid fatty acids) concentration [figure 3], which consist in the main component of the cell membrane of most microbes, including the soil ones.

In this case too the graph [figure 2] seems to show a straight directly proportional relationship between respiration rate and PLFA concentration and PH growth, meaning that microorganisms optimum ph conditions tend to be either neutral or slightly alkali, particuralrly for respiration the best fit line on the graph displays a steeper line with a bigger gradient.

Conclusion

As a hypothesis i would say that the best results in terms of mass gaining and length should be matched by the radish seeds growing in an alkali or neutral enviroment, rather than in an acidic one To revisit my hypothesis and understand why the base solution should provide better nutrients for the radish rather than the other ones it is very important to understand the concept of CEC (Cation Exchange Capacity), this property of the soil is defined as: “The total number of cations a soil can hold–or its total negative charge–is the soil’s cation exchange capacity”[1] the capacity of the soil to contain these ions is measured in millequivalents per 100 grams of soil (meq/100g) the increase of this soil property is usually associated with an increase of fertility, the reason being that the higher the CEC the higher the maximum amount of nutrients (ions) [figure 4]the soil is capable of holding and more likely it is to improve its productivity.

The increase in CEC is usually associated to a decrease in pH (showed in the graph [figure 5]). This has been prooved by Dr Lloyd A. Peterson who carried out an experiment of soil acidification through the use of N fertilizers [2] (the main chemical in these compounds is Ammonia, NH3, which as it’s released in the soil is converted into ammonium nitrate by the bacteria, during this biological process, 3 positive hydrogen ions are released in the soil per ammonia molecule converted. The increase in the H+ ions concentration makes the soil acidic.) which eventually lead to a much higher CEC rate, which should theoretically improve the soil fertility itself, but, as a side effect of the acidification is a drastic decline registered for the exchangeable base cations particularly in the ions Ca2+, which suffered of – 31% exchangeability and a – 36% for Mg2+[3] actually worsened the fertility of the soil since the ECEC (effective cation exchange capacity, calculated by adding the exchangeable base cations and the exchangeable acidity) actually turned out to be negative, meaning that the relation between pH and the ECEC itself is actually directly proportional.

To conclude, in the case of radish especially, the ions suffering from base cation exchangeability decrease, which are magnesium and calcium make up a big part of the nutrients absorbed by the seeds (see the background paragraph) this causes the radish growth to be damaged by an acidification of the soil. This explains why roots growing in acidic conditions should display the worst results, while the ones living in alkali and neutral soils should grow longer and heavier, because the ECEC along with the nutrients concentration in the soil varies depending on the change in pH, in this case with a linear directly proportional rate, meaning that as pH increases (towards alkali) so does the base cations nutrients concentration in the soil and the plant growth benefits from it.

Effects of Soil Ph on Radish Plants Growth Essay

Bags of Reactions Lab Essay

Bags of Reactions Lab Essay.

* Problem/Purpose * Background Information: The Law of Conservation of Mass was created by Antoine Lavoisier in the 18th century. This law stated that mass could matter could neither be created nor destroyed. During a reaction the bonds of the reactants are broken and form new substances. As stated in the Law of Conservation, matter can neither be created nor destroyed; because of this the products should have the same number and type of atoms as seen in the reactants. * Purpose: Test the Law of Conservation of Mass.

* Hypothesis: If we weight the mass of the materials before and after the reaction, then we can prove if the Law of Conservation of Mass is true.

* Materials:
* Goggles
* 25mL graduated cylinder
* 2 resealable bags
* Scale
* Antacid tablet
* Scoopula
* CaCl2 , Calcium Chloride
* NaHCO3 , Sodium Hydrogen Carbonate
* Universal Indicator

* Procedure
Part A

1. Measure 25mL of water and put into a resealable bag. Flatten air out of the bag and seal it. Record the mass in Table 1.

2. Record the mass of the antacid tablet in Table 1 3. Tip the bag sideways, and while holding the bag this way, add the tablet and water so not mix. Do not trap any extra air in the bag. Reseal the bag. 4. Let the tablet drop into the water. Observe the reaction until it comes to a complete stop. Record the observations. 5. When the reaction is complete, record the mass of the bag and its contents in Table 1. Part B

6. Add two scoops of CaCl2 to the second bag 7. Add one scoop of NaHCO3 to the bag and shake gently to mix. 8. Determine the mass of the bag and its contents. Record in Table 2. 9. Measure 25mL of water in a graduated cylinder. Add 10 drops of Universal Indicator to the water. 10. Tip the bag sideways, and while holding the solids in the upper part of the bag, pour the water into the bag so the solids don’t mix. 11. Keeping the trapped air to a minimum, reseal the bag. Hold the bag and let the liquid move from one end of the bag to the other until the contents are mixed. 12. Observe the reaction until it comes to a complete stop. Record your observations 13. Record the mass of the unopened bag in Table 2. Clean up your work and wash your hands before leaving the laboratory.

* Data/Results
Table 1: Antacid and Water|
Mass of bag and water| 27.085g|
Mass of tablet| 3.21g|
Mass of bag and reactants| 30.305g|
Mass of bag and products| 28.14g|

Table 2: CaCl2, NaHCO3, and Water|
Mass of bag and dry reactants| 4.09g|
Volume of water| 25mL|
Mass of water| 24.925g|
Total mass of bag and reactants| 29.015g|
Mass of bag and products| 27.37g|

* Analysis/Conclusion

A. Analysis Questions:
1. How do the values for the total mass before and after each reaction demonstrate the law of conservation of mass? The values seem to be in the same general value 2. What were three observations you made that indicated a reaction had occurred in part A? The tablet started to fizz, the bag began to fill with gas, and you could hear the tablet reacting with the water. 3. An indicator changes color when the acidity of a solution changes. What evidence is there that such change occurred in Part B? The universal indicator changed to a yellowish orange color 4. Did the reaction in Part B become more acidic or basic? More acidic

B. Conclusion: The lab showed us that the Law of Conservation of Mass is correct. I feel that there were some mistakes in the lab. The size of the scale we were using was not large enough to fit the entire bag on for weighing. I feel that this affected the results we recorded for mass. If I were to redo this experiment I would be sure to use a bigger scale. I feel the data was also affected by extra air left in the bag. The results are close enough to show that the Law of Conservation of Mass is possible though when you take into accounts the problem we had with the lab.

Bags of Reactions Lab Essay

Mosquito Killer Essay

Mosquito Killer Essay.

The study is entitled Combined solution of Garlic (Allium sativum) and Lemongrass (Cymbopogon citratus). Specifically, it sought to find out how these two solutions (lemongrass and garlic) can effectively kill mosquitoes. It aimed at looking for an organic and safe measure in treating the abundance of mosquito. Ideally, the researcher’s study promotes a tandem between science and creation’s conservation. The materials composing the solution were 40 mL of the combined solution of Lemongrass (Cymbopogon citratus) and Garlic (Allium sativum). The set up was composed of experimental and control group.

The experimental group was being sprayed using a specific commercial pesticide. On the other hand, the control group was being sprayed using the organic mosquito killer. Data were collected to gather relevant information. In the light of the findings of the study, it was found out that the solution composing of 40 mL solution of Garlic (Allium sativum) and Lemongrass (Cymbopogon citratus) extract can kill mosquitoes in a short span of time compared with the commercial one.

It took only _________before the mosquitoes died.

CHAPTER 1
INTRODUCTION

Mosquitoes are vector agents that carry disease causing viruses and parasites that lead to life-threatening diseases from one person to person without catching the disease themselves. It prefers people over others. The preferential victim’s sweat simply smells better than others because of the proportions of the carbon dioxide and other compounds that make up the body odor. A large part of the mosquito’s sense of smell is devoted to sniffing out human targets. Mosquitoes are estimated to transmit disease to more than 700 million people annually in Africa, South America, Central America, Mexico, and much of Asia with millions of resulting deaths. At least 2 million people annually die of these diseases.

Today, not just our whole country, Philippines, but also the entire world is facing huge problems in relation to the abundance of mosquitoes in the community. In fact, many alternatives and methods such as different kinds of drugs, vaccines, insecticides, nets and repellants are now discovered and created in order to eradicate mosquitoes, prevent diseases, and protect individuals. We opted to make this study to pursue an alternative organic agent of mosquito eradication. The result of this study is to propose an alternative but organic and safe solution in treating the abundance of mosquito in our locality. Moreover, this aimed to significantly help the residents who are greatly affected by these mosquitoes in a way that this study will provide them a new avenue in treating the great number of mosquitoes.

STATEMENT OF THE PROBLEM

This study entitled Garlic (Allium sativum) and Lemongrass (Cymbopogon citratus) as Mosquito Killer is aimed to know the insecticidal effect of Allium sativum and Cymbopogon citratus on mosquitoes in terms of: a. How effective is the Garlic (Alium sativum) and Lemongrass (Cymbopogon citratus)? b. What is the compared time duration of the commercial product and experimental product?

HYPOTHESIS

The study hypothesized that the combined solution of Garlic (Allium sativum) and Lemongrass (Cymbopogon Citratus) is more likely effective than commercial product on mosquitoes in terms of the number of mosquitoes that will die.

SIGNIFICANCE OF THE STUDY

The conduct of this study is significant in lessening the number of mosquitoes all over the country. This would extend an alternative solution for everybody spend less amount of money in treating the abundance of mosquitoes here in our locality and therefore cooperation and resourcefulness will primarily be observed by the people. Specifically, this will bring benefits to the following: Government. This would provide the government a new avenue in lessening the number of mosquitoes. The materials that will be used are recycled and organic in which their availability is easily utilized and therefore they will spend less amount of money in treatment for the abundance of mosquitoes in the society.

Residents. This study raises the awareness level of residents in our country. They would be able to foresee the importance of being resourceful of the things in our surroundings.

SCOPE AND LIMITATION

This study focused on the insecticidal effect of Garlic (Allium sativum) and Lemongrass (Cymbopogon citratus) on mosquitoes. The materials used were just gathered around the researchers’ household. The investigation utilized 6 mosquitoes that were placed in a transparent container.

DEFINTION OF TERMS

Mosquito. From the Spanish or Portuguese meaning little fly is a common insect in the family Culicidate (from the Latin culex meaning midge or gnat). Mosquitoes resemble crane flies (family Tupilidae) and chironomid flies (family Chironomidae), with which they are sometimes confused by the casual observer. Organic. Any member of a large class of chemical compounds whose molecules contain carbon. Geraniol. A monoterpenoid and an alco0hol. It is the primary part of rose oil, palmarosa oil, and citronella oil (Java type). It also occurs in small quantities in geranium, lemon, and many other essential oils. Solution. A homogenous mixture composed of two substances. Erradicate. Get rid of something completely.

Insecticide. A chemical substance used to kill insects.

REVIEW OF RELATED LITERATURE

Allium sativum yields allicin, an antibiotic and antifungal compound (phytoncide). It has been claimed that it can be used as a home remedy to help speed recovery from throat or other minor ailments because of its antibiotic properties. It also contains the sulfur-contaning compounds alliin, ajoene, diallylsulfide, dithiin, S-allylcysteine, and enzymes, vitamin B, proteins, minerals, saponins, flavonoids, and maillard reaction products which are non-sulfur containing compounds. Furthermore a phytoalexin called allixin was found, inhibiting skin tumor formation. Herein, allixin and/or its analogs may be expected useful compounds for cancer prevention or chemotherapy agents for other diseases.

The composition of the bulbs is approximately 84.09% water, 13.38% organic matter, and 1.53% inorganic matter, while the leaves are 87.14% water, 11.27% organic matter, and 1.59% inorganic matter. Fresh C. citratus grass contains approximately 0.4% volatile oil. The oil contains 65% to 85% citral, a mixture of 2 geometric isomers, geraniol and neral. Related compounds geraniol, geranic acid, and nerolic acid have also been identified. More than a dozen of other minor fragrant components were also found. Research has shown geraniol to be an effective plant-based mosquito repellant. Another popular theory is that ingesting garlic can provide protection against mosquitoes. A University of Connecticut study examined this claim with a randomized, double-blinded, placebo-controlled crossover study.

The data didn’t provide evidence of significant mosquito repellence. However, subject only consumed garlic once, and the researchers say that more prolonged ingestion may be needed. There are also other natural mosquito repellants that are being researched like the Fennel, Thyme, Clove oil, Celery extract, Neem oil, Vitamin B1. Biopesticide insect repellants (sometimes called “natural”, “botanical” or “plant-based”) has been proven to be as effective as those containing synthetic chemical compounds like DEET. Remember, however, that “natural” doesn’t always mean safe, so you should use plant-based insect repellants as carefully as any other. With the literature presented above, it can be seen that the study has some bearing capabilities and properties to other work in the sense that it tackles the capacity of some organic materials such garlic juice and lemongrass oil as effective mosquito repellant.

Mosquito Killer Essay

Explanation of the Multistep Synthesis of Benzilic Acid Essay

Explanation of the Multistep Synthesis of Benzilic Acid Essay.

The synthesis of several complex organic compounds follows a multistep synthesis. “Multistep synthesis” refers to the procedure in which the product of one reaction serves as the starting material in the subsequent reaction. The multistep synthesis of benzilic acid begins with a conversion benzaldehyde to benzoin through a condensation reaction. The benzoin then oxidizes into benzil, which undergoes rearrangement to give benzilic acid.

Benzoin Synthesis

* When two benzaldehyde molecules condense in the presence of thiamine, it leads to the formation of a molecule of benzoin.

The thiamine behaves as a coenzyme catalyst. This step of the reaction involves the addition of ethanol and sodium hydroxide into an aqueous solution of thiamine hydrochloride and creating a reaction with pure benzaldehyde. When you heat this mixture to a temperature of 60 degrees Celsius for about 90 minutes and then cool it in an ice bath, the benzoin crystallizes out. Recrystallization of these crystals from hot ethanol yields pure benzoin as a colorless powder.

Benzil Synthesis

* Benzoin undergoes oxidation in the presence of a mild oxidizing agent such as nitric acid to produce the alpha diketone known as benzil.

When you heat benzoin with concentrated nitric acid using a reflux condenser, evolution of reddish brown nitrogen dioxide occurs and then stops. When you add cold water to the cooled reaction mixture, benzil precipitates out as a yellow solid. You can then recrystallize this substance from hot ethanol.

1. Benzilic Acid Synthesis

* When you reflux a solution of benzil in ethyl alcohol with potassium hydroxide for 15 minutes and then cool it, it forms the carboxylate salt potassium benzilate. When you dissolve this salt in hot water in an Erlenmeyer flask and add hydrochloric acid to bring the pH down to 2, the salt becomes acidified to yield benzilic acid.

Precautions

* During the conversion of benzaldehyde to benzoin, you must maintain temperatures below 65 degrees Celsius to obtain benzoin. Take care when refluxing benzoin with nitric acid; the nitrogen dioxide fumes are extremely toxic and can cause lung damage. During the conversion of benzoin to benzil, some benzoin may remain unoxidized. Prevent this scenario by creating a reaction of an ethanolic solution of the benzil with 10 percent sodium hydroxide solution; if benzoin is present, a purple color develops.

Explanation of the Multistep Synthesis of Benzilic Acid Essay

Locating Tetrahedral and Octahedral Voids Essay

Locating Tetrahedral and Octahedral Voids Essay.

The close packed structures have both octahedral and tetrahedral voids. In a ccp structure, there is 1 octahedral void in the centre of the body and 12 octahedral void on the edges. Each one of which is common to four other unit cells. Thus, in cubic close packed structure.

Octahedral voids in the centre of the cube =1

Effective number of octahedral voids located at the 12 edge of = 12 × 1/4 = 3∴ Total number of octahedral voids = 4

In ccp structure, there are 8 tetrahedral voids. In close packed structure, there are eight spheres in the corners of the unit cell and each sphere is in contact with three groups giving rise to eight tetrahedral voids

Circles labelled T represent the centers of the tetrahedral interstices in the ccp arrangement of anions.

The unit cell “owns” 8 tetrahedral sites. Circles labelled O represent centers of the octahedral interstices in the ccp arrangement of anions (fcc unit cell). The cell “owns” 4 octahedral sites.

Illustration 16. In a solid, oxide ions are arranged in ccp.

Cations A occupy one – sixth of the tetrahedral voids and cations B occupy one third of the octahedral voids. What is the formula of the compound?

Solution: In ccp with each oxide there would be 2 tetrahedral voids and one octahedral voids 1/3rd octahedral voids is occupied by B and 1/6th tetrahedral void by A. Therefore the compound can be

Illustration 17. In a crystalline solid, having formula AB2O4, oxide ions are arranged in cubic close packed lattice while cations A are present in tetrahedral voids and cations B are present in octahedral voids .

Locating Tetrahedral and Octahedral Voids Essay

The Chemistry of Hair Coloring Essay

The Chemistry of Hair Coloring Essay.

The first thing that comes to mind when people see hair color is “beauty. ” But, what most do not realize is that chemistry plays a major role in many everyday products. What makes the colors so pretty and attractive? How can hair color effect synthetic hair? The question I want to answer is “what are the effects of hair color on synthetic hair? ” I chose this topic because I wanted to learn how to color hair and apply it to chemistry.

Hair coloring is a form of organic and inorganic chemistry. Organic chemistry involves carbon, whereas inorganic chemistry does not.

Hair color is (or can be) a permanent chemical that is used to put a specific color in hair for vanity, or any other cause. There are various types of hair color such as: permanent, semi- permanent, rinses, and bleaches. Schuller is also known as the founder of L’Oreal, the world’s leading country in cosmetics and beauty. But, even before then, people have been coloring their hair for centuries.

Many things that were used as medium were plants and minerals that have contained henna (temporary), and black walnut shells. Also, many of these techniques are used in modern-day salons.

Such techniques include adding foil in the hair for a better outcome. My hypothesis is that if I apply hair color to two kinds of synthetic hair (Milky Way: Shake n’ Go, Sample A and Express Lock Sleek, Sample B), then there will be a better outcome on Sample B. I believe that my hypothesis is correct because Sample A is a less expensive brand. The brand matters because the more expensive the hair, the better the quality. So, what is synthetic hair? Synthetic hair is material that appears to be hair, but is actually made of non-human fibers such as Kanekalon, which is man-made hair, and Mono-fiber.

Synthetic hair is commonly called “weave. ” The fibers are flammable and can spark a fire in no less than ten seconds if exposed to an open flame. Before I started my experiment, I gathered my materials. The materials needed for this experiment were: I used two types of hair color, Bigen (Blue Black) and Bigen(Light Chestnut) (box containing: the dye powder), gloves, mixing bowl, water, basting brush, and a comb. I used two types of synthetic hair, Milky Way Shake n’ Go (Sample A) and Milky Way SAGA (Sample B). But, since I am not coloring an actual person’s hair I don’t need shampoo, conditioner, tipping cap, or a comb.

When I started the experiment, first, I pulled back my hair and took off any loose accessories. Next, I put on gloves and a smock to protect my skin from chemicals. After I was covered completely, I started the experiment. First, I poured the dye powder into a plate since I did not have a mixing bowl. Next, I got a half of a cup of water and mixed it with the powder. After the solution was evenly mixed, I let it sit for about one minute. I cut the samples in half to have data on my board. When the samples were cut in half, I took the basting brush and covered the samples with color.

When the color was on the hair, I had to let them sit for thirty minutes. When the thirty minutes passed, I rinsed the hair twice each and set them in sandwich bags labeled: A and B. When the experiment was over, I cleaned all of the tools I used and my area off. When going back over what I did in my experiments I recorded my observations. In the experiment, when I was mixing the hair color, as I mixed the solution got thicker and thicker. The hair that I used was very thin and soft. What are the effects of hair color on synthetic hair?

My hypothesis was that if I apply hair color to two kinds of synthetic hair, then there will be a better outcome on Sample B. I thought that my hypothesis was right because Sample A is a less expensive type of hair. My hypothesis was rejected because although Sample A was less expensive, it was thicker and could take in more color that Sample B. My results did not support my hypothesis. In the experiment, I learned that coloring hair is strongly related to chemistry. It is related to chemistry because it requires mixing chemicals and creating new solutions.

The Chemistry of Hair Coloring Essay

The Contact Process Essay

The Contact Process Essay.

The Contact Process is the name given for the manufacture of Sulphuric Acid (H2SO4(l)). There must also be specific conditions of temperature, pressure and catalyst for the reaction to occur effectively. I will also look at the effect of temperature, pressure and catalyst on the composition of the equilibrium mixture, with respect to Le Châtelier’s principle.

THE PROCESS

Firstly, Sulphur Dioxide (SO2(g)) is manufactured by burning Sulphur (S(s)) in air. The sulphur dioxide is then purified.

S(s) + O2(g) →SO2(g)

Secondly, Sulphur trioxide (SO3(g)) is produced by reacting sulphur dioxide with O2(g) over a vanadium(v) oxide, V2O5 catalyst at 450 oC and 2 atm.

2SO2(g) + O2(g) ⇌2SO3(g)

Thirdly, oleum is formed by dissolving concentrated sulphuric acid in the sulphur trioxide.

SO3(g) + H2SO4(l) → H2S2O7(l)

Lastly, oleum is diluted with water, forming concentrated sulphuric acid.

H2S2O7(l)+ H2O(l) → 2H2SO4(l)

It should be noted that due to the reaction being extremely exothermic, causing the sulphuric acid to vaporise forming a highly corrosive mist, the sulphur trioxide cannot be directly added to the water.

EQUILIBRIUM

1) CONCENTRATION

According to Le Chatelier’s Principle, Increasing the concentration of oxygen in the mixture causes the position of equilibrium to shift towards the right. There are 3 molecules in the reactants and 2 in the product. There is more concentration on the left so increasing the concentration will favour the forward reaction. Since the oxygen comes from the air, this is a very cheap way of increasing the conversion of sulphur dioxide into sulphur trioxide.

2) TEMPERATURE

You need to shift the position of the equilibrium as far as possible to the right in order to produce the maximum possible amount of sulphur trioxide in the equilibrium mixture.

The forward reaction (the production of sulphur trioxide) is exothermic, and according to Le Chatelier’s Principle, this will be favoured if you lower the temperature. The system will respond by moving the position of equilibrium to counteract this – in other words by producing more heat.

3) PRESSURE

According to Le Chatelier’s Principle, if you increase the pressure the system will respond by favouring the reaction which produces fewer molecules. That will cause the pressure to fall again. In order to get as much sulphur trioxide as possible in the equilibrium mixture, you need as high a pressure as possible. High pressures also increase the rate of the reaction.

4) CATALYST

The catalyst has no effect whatsoever on the position of the equilibrium. Adding a catalyst doesn’t produce any greater percentage of sulphur trioxide in the equilibrium mixture. Its only function is to speed up the reaction.

The Contact Process Essay