Chemistry Essays

Aldol condensation proceeds via an addition reaction between an aldehyde and a ketone, resulting in the formation of an aldol. The aldol product undergoes dehydration to give an enone product. In the present experiment, benzaldehyde, an aldehyde, reacts with acetone, a ketone, to give dibenzalacetone.

Hence all efforts must be channeled to find a robust vaccine for preventing it. Hence, research in this area is going at an intense pace in recent years. But unfortunately, there are no foolproof vaccines that have been formulated yet. A vaccine by name RTS S/AS01, which was put to trial during 2009, is specifically addressed to vulnerable children in the Third World.

The experiment was meant to identify various gases by investigating their physical and chemical properties. Some chemical reactions or chemical decomposition reactions result in the production of gaseous products. For instance, hydrogen gas can be prepared in the laboratory through the reaction of a reactive metal and a strong acid.

since during the manufacturing of the drug various factors such as change in temperature and moisture can alter its toxicity, actions, kinetics and dynamics as well.(Giron,2002).To understand the solid state properties and the key to efficient characterization of the compound is to formulate a strategic technique and elaborate analytical programs that enables us to understand the chemical, structural, energetic and physical states of the compound.(Lee,2003) Fundamental properties that need to be analyzed in a solid dosage form Test Method/ function Characterization Fundamental properties 1) UV spectroscopy Simple assay 2) Solubility Phase solubility/ purity 3) Melting point DSC-polymorphism

Generally enzymes are classified into six different groups; oxidoreductases, transferases, hydrolases, lyases, isomerases and ligases. Sphingomyelinases (SMase) are hydrolytic enzymes that catalyze the conversion of sphingomyelin, which is also known as ceramide phosphorylcholine into ceramide and phosphorylcholine (Goni and Alonso 38).

In the latter literature presented therein, we would fundamentally look into various methods and definitions employed to exactly what heat and temperature are with regards to the kinetic theory of matter and how they particularly influence this law.

X-ray Crystallography. Prior to the discovery of X-rays in 1895 (Nelson), the general concept about the crystals was that these consist of an orderly arrangement of atom, ions or molecules. As there was no definite clue, only a general imaginary concept about these crystals prevailed.

CHX is more soluble in ethanol however; ethanol is too volatile and reactive so that 50:50 ethanol-water mixture was used as CHX solvent. One milligram CHX per milliliter solvent was prepared. This was done by measuring 0.1 mg CHX in a 100 ml volumetric flask, filling the flask to the mark with the solvent, and shaking it until CHX was completely dissolved.

ICI had employed the process of autoclave when they first commercialized the process in 1938. The tubular process was first invented by BASF in 1938 though it took another 15 years to commercialize the production processes. Cost reduction and product enhancement has been the goal of each manufacturer over the years.

The rapid increase in CYN producers in temperate zones is yielding concern on the impact of this toxin to human, as well as environmental risk and health risks across the contents. Since 2000, there are several studies that have demonstrated the capacity for Cylindrospermopsin (CYN) to bio-accummulate especially in freshwater organism.

The caloric content of food is thus altered through the use of heat in a series of reactions. The reactions that occur can either release amount of heat or can absorb it in form of energy (Kotz, Treichel & Townsend 214). Furthermore, this event can cause the matter to change in form from one state by either melting to boiling.

These copolyesters have unique properties that make them highly versatile for use in industrial applications. These are thermoplastic polyesters of the condensation type, and possess properties such as flexural fatigue resistance, impact resistance, creep resistance, load bearing capacity and resilience (Fakirov 2005).

These data are useful in finding out whether another planet such as Mars has hosted life, or water bodies on its surface or underground. Correlations between a terrestrial lake and the geology of Mars are useful for forming analogs, and for understanding further about the other planet.

Most of the clean water, about 70 percent, is used up by the agricultural sector. Clean water has reduced a lot recent times due to natural and other reasons and this is something which is of huge concern for human beings. The biggest factor that has led to a reduction in the quantity of safe and clean water is water pollution.

Strong covalent and hydrogen bonds join the atoms within their structures. Carbohydrates comprise of a wide range of substances broadly distributed and available in nature. In plants, carbohydrates account to over 75% of the dry weight, which is mainly in form of lignin, cellulose and starch (Pigman, 63).

It also acts as an antipyretic drug where it reduces fever and an anti-inflammatory agent capable of reducing the swelling and redness associated with inflammation. Due to its ability to acts as an anticoagulant, aspirin is an effective agent in the prevention of strokes and heart attack.

In order to resolve this issue the authors proposed to add alkyl groups to the outer edges of the dicyclopentadiene rings which form the content of this paper. Several synthesis routes are proposed and their respective yields are reported. It was also desired to test a synthesis route that began with RuCl3·3H2O instead of Ru3(CO)12.

Accurate prediction of the solubility of a compound during drug screening may immensely help the pharmacological industry by assisting in the selection of the right drug candidate that is sufficiently soluble and bioavailable.2 Thus, a number of computational and theoretical models have been proposed to predict the solubility of a compound.

In this paper, carbon sequestration will be studied in respect to geosequestration which involves directing and storing carbon gases out of the atmosphere. These two terms will be used interchangeably in this literature. Greenhouse gases are mainly injected into oil field after depletion or water bodies such as oceans and saline aquifers.

It is also is available in the form of 2.5 or 5 single dose nebuliser solution. Brand names for such are Asmoluni-dose, GenRx Salbutamol, Butamol 2.5, Pharmacor Salbutamol, Salbutamol Sandoz, Salbutamol GA, VentolinNebules, and Salbutamol Sulfate. CFC-free oral free inhalers are available as Asmol CFC-free, Ventolin CFC-Free, Airomir and AiromirAutohaler (with breath actuated device), and APO Salbutamol inhaler.

One of the main features of such polymers is low, controllable viscosity which can be adjusted through the introduction of monomeric units possessing the ability to interact with the chain stoppers. The main purpose of the work was to isolate small receptor molecules which contained AADD hydrogen bonding in their structure.

The many improvements in materials properties include electrical conductivity, toughness, optical properties, shear and bulk modulus, film scratch resistance, yield strength and many more. The addition of nanofillers such as carbon black to rubbery polymers has a great effect upon the properties of such materials and only very small amounts of nanoparticles are dispersed in the polymer matrix (Dzenis 2004).

Many western countries such as USA, Australia, New Zealand, and Singapore, even some part of Europe have adopted fluoridation method to greater extent. Also, some Asian countries such as India, China have high concentration natural sources of fluoride in the water.

Theories There are three important steps in mass spectrometry. First, the compound is converted into cations by loss of an electron. These ions are produced by driving a high energy beam of electrons, which displaces the electrons from the compound. Sometimes, cations split further into neutral fragments and smaller cations.

These events have unfortunately created misconceptions about nuclear power, which highlight more on perceived disadvantages than its benefits. This paper is a critical examination of nuclear energy focusing on its advantages and disadvantages in relation to other sources of energy.

Test in vitro all the synthesized resveratrol derivatives to prove their efficiency as LTA4 hydrolase inhibitors and as novel, promising molecules in cancer treatment. Experimental section General information Flash chromatography was performed using Merck silica gel 60 (230-400 mesh) NMR spectra were obtained at 400 MHz (H1), Bruker AV500 NMR spectrometer in CDCl3.

Organocatalysts is a term that comes from two chemical terms organic and catalyst. It refers to a catalyst that comprises of organic compounds. Scientists argue that the ability to produce and recycle multiple reactions increases the efficacy of organocatalysts.

Later on he developed the law of combining volumes to demonstrate the behavior of compounds when combined. Gay-Lussac was also involved in discovery of chemical elements which are the basis for the studies in chemistry and physicist. However, some of his works are credited to other scientist while of the discoveries attributed to him were actually made by other scientists.

The name comes from the orange stripe used to label the barrels containing the chemical. Comparing to other “Rainbow chemicals”, Agent Orange was the most extensively used. Being a herbicide, the compound was employed in the United States, Korea, Canada, Australia and Brazil (Hay 151).

The discovery of fuel cells in 1839 by Sir William Groves has contributed to the use of a more environmental friendly device (Sorensen 34). Fuel cells are electrochemical devices that generate energy through chemical reactions. They utilize elementary oxygen and hydrogen to generate energy.

A free radical can be defined as a particle with at least one unpaired electron occupying the outermost shell, capable to exist independently (Karlsson, 1997). In other words, there is at least one electron without a pair. The presence of unpaired electrons usually makes free radicals highly reactive.

The positive components that result from this electron bombardment are then accelerated into a vacuum through a magnetic field. It is in this magnetic field that the components are eventually sorted on the basis of mass to charge ratio. Because a majority of the ions produced in the mass spectrometers are positively charged, they are cations; these ions tend to carry an overall unit positive charge.

Introduction Plants are important in the continuing existence of life, as it provides food for animals. What is interesting about plants is that they make their own food, and factors that may affect this can understandably deplete resources for the other functions of the plant, such as growth.

The system has a disposable chip. This chip checks for cross contamination collect analyzed sample and to freely measurement. CTC is salient biomarkers for so many cancers. There are many systems for enumeration based on either EpCAM/CD326 which express tumor cell before microscope or RT-PCR.

The world is composed of atoms which are the smallest indivisible particles of matter “made up of negatively charged electrons in orbitals around positively charged nuclei” (RBI 1988, p.53). Atoms integrate through interactions between electrons to form units termed as molecules.

According to Cornell University, department of animal science, the toxic chemical is produced by certain foods or feeds. These mycotoxins are the most studied of all toxins in the world, and known to cause diseases such as aflatoxicosis. The occurrence of this toxin is greatly influenced by the environmental factors, thus its contamination varies depending on the geographic location, agricultural practices and the susceptibility of the food substances to fungal infections during the pre-harvest, harvest and storage times.

Composition of intracellular fluid remains relatively stable as compared to the extracellular fluid. This is due to the fact that ECF has to interface with the changes in the external environment therefore modifications in its constituents are inevitable.

Using both redox reaction between vitamin C extract and iodine solution, and vitamin C extract and sodium hydroxide solution, the experiment will carry out titration reactions and apply stoichiometry concepts to determine the percentage of vitamin C in a tablet.

By definition, heavy metals have a density of 5.0/gcm3 or more which is much heavier than the density of an average soil particle. They occur naturally in rocks but their concentrations are regularly augmented due to contamination and pollution. The most common heavy metals with respect to possible hazards are mercury, lead and cadmium and chromium.

According to World Meteorological Organization, there was almost a 30% increase in the Earth’s atmosphere in a span of two decades. It is important to discuss this greenhouse gases and its environmental effects as most anthropomorphic activities produce these gases.

Electrochemistry entails association of electrical properties and chemical substances in a reaction. Electrical properties commonly measured include conductance, resistance, current and voltage.

Analysis of Galanin Using Mass Spectrometry Introduction Galanin is known to play an important role in the regulation of food intake. Poritsanos et al. (2009) report that it affects the central nervous system. They carried out studies on the relationship between obesity and the levels of galanin in the serum.

Antidepressants are usually categorized on the basis of their chemical structure and an example of drugs in this group is the tricyclic antidepressants. Anti-depressants can also be categorized on the basis of their function and an example of drugs in this group is the monoamine oxidase inhibitors.

In proteomic studies, especially in clinical application, sensitivity and accuracy is of importance. Proteins are complex large molecules that are non-volatile and their activity is based mostly on their structure rather their primary structure. The ES-MS provides the perfect analytical tool for studying these molecules since it explores both structure (qualitative) and concentration/molecular weight (quantitative) of the peptide of interest.

If the manufacturers do not comply with the additive legislation, then action should be taken against them to protect the consumers because it is their right. Additionally, people should be educated on the effects of high intake of beverages that contain caffeine and benzoic acid.

(1) Describe the general properties of the atmosphere known as troposphere, stratosphere and the ionosphere. Describe the composition of unpolluted air at sea level. The unpolluted air or atmosphere at sea level is chiefly made of gases kept in place by the effect of Earth’s gravity at an average temperature of about 14 C.

On the other hand, a compound is made of two or more elements held together by chemical bonds (Leong & Aik, 2009). The differences between mixtures and compounds are discussed below: A mixture lacks fixed composition while a compound has a fixed composition.

Just like the invention of light bulb and Hubble telescope, the concept of Quantum first came into light in the mid- 1800s. During this time, the word quantum carried no meaning other than its literal meaning of “to quantify”. Nonetheless, as field of chemistry and physics expanded, the idea of quantum began to occur in our daily lives.

According to Wilhelm Kuhn (Kuhne, 1997) enzymes are biological molecules which increases or reduces the rate of a biochemical reaction. A catalase is an enzyme that grows in the presence of oxygen. Hydrogen peroxide is highly toxic and therefore its need to be eliminated.

Also, included in this letter are advices, and controls that you may undertake to solve your asbestos problem. Asbestos and Its Common Uses First, I would like to discuss to you the general information on asbestos. According to the Agency for Toxic Substance and Disease Registry [ATSDR] (2001), asbestos is a common term that often refers to anthophyllite, tremolite, actinolite, amosite, crocidolite, and chrysotile.