Search Results Chemistry

Free Essays Unrated Essays Better Essays Stronger Essays Powerful Essays Term Papers Research Papers

Your search returned over 400 essays for "Chemistry". To narrow your search results, please add more search terms to your query.
[<< Previous] [1] [2] [3] [4] [5] [Next >>]

These results are sorted by most relevant first (ranked search). You may also sort these by color rating or essay length.
Title Length Color Rating  
Laws of Conservation of Mass and Energy - Introduction In any science that requires computation, specifically in Chemistry, gathering measurements of various physical and chemical properties need to be strictly accurate and precise for it is in this most crucial phase that either make or brake the quality and value of science. No matter how good one may perform the experiment, without forethought on how to gather data correctly, the collected information would not be reliable enough to draw out a conclusion on it. The main objective of this experiment is to explain thoroughly the reacting system which can be done through scientific observation because it is through this vital step that the facts needed to elucidate the reacting system are obtained....   [tags: Chemistry] 1224 words
(3.5 pages)
Better Essays [preview]
The Chemical Dynamics of Cadmium in the Soil Environment - ... As Cd is a toxic metal to humans [3] and animals alike, the environmental and soil contamination with Cd is becoming of great concern in the last few decades. Therefore, it is important for chemists, environmental scientists and engineers to understand the chemistry of Cd interactions in soils to understand its bioavailability. Millions of tonnes of hazardous waste containing CD are generated in the world on yearly basis. Because of the inefficient waste handling techniques and hazardous waste leakage in the past, thousands of sites, especially in industrial world were contaminated by heavy metals, organic compounds and other hazardous materials....   [tags: Chemistry] 979 words
(2.8 pages)
Strong Essays [preview]
The Affects of Different Yeast on the Rate of Fermentation - ... This is therefore an anaerobic process. This is the final stage and this is where the final conversion of fructose and glucose into ethanol and improvements to the aromas and final flavours of the wine are produced. (WineDefintions Staff Writer) There is also a third process of fermentation known as malolactic fermentation. This can occur naturally in the wine if there is wild yeast remaining but is often encouraged by winemakers by adding in bacteria to cause this process to occur. In malolactic fermentation, malic acid is converted into lactic acid by a naturally occurring process in which bacteria feeds on the malic acid....   [tags: Chemistry ] 1156 words
(3.3 pages)
Better Essays [preview]
Enaminone Derivatives - ... The NMR spectra were recorded on a Varian Mercury VXR-300 NMR spectrometer.1H NMR (300 MHz) and 13C NMR (75.46 MHz) were run in deuterated chloroform (CDCl3) or dimethylsulphoxide (DMSO-d6). Chemical shifts were related to that of the solvent. Mass Spectra were recorded on a Shimadzu GCMS-QP1000 EX mass spectrometer at 70 eV. Elemental analyses were carried out at the Microanalytical Centre of Cairo University, Giza, Egypt. All reactions were followed by TLC (Silica gel, Aluminum Sheets 60 F254, Merck)....   [tags: Chemistry ] 2461 words
(7 pages)
Powerful Essays [preview]
Social Relevance Report: Caffeine - ... 2.2 Physical Properties of Caffeine Pure caffeine is odourless, white in colour, looks like fleecy masses, glistening needles or powder and has a bitter taste. Table 1.1 Physical properties of caffeine Physical property Values/ Measurements Boiling point 178 °C (sublimes) Melting point 238 °C Density 1.2 g/cm³ Volatility 0.5% Vapour pressure 101 kPa at 178 °C pH value 6.9 (1% solution) Solubility in water 2.17% Vapour density 6.7 g/m³ Molecular weight 194.19 g/mol (PERGAMON PRESS, 1996) 2.3 How Caffeine Works in the Human Body Caffeine is believed to act on the brain and other organs by blocking adenosine receptors (thereby blocking a pathway that leads to the breakdown of cyclic adenosine monophosphate, cAMP)....   [tags: Chemistry]
:: 12 Works Cited
1779 words
(5.1 pages)
Better Essays [preview]
phase diagram - ... However, the temperature probe notices the first changes in temperature, and from the data points collected one can determine when the slope of the graph starts to plane, and therefore determine when crystallization occurs. Furthermore, the ice water bath had a tendency to cause some condensation on the outside of the beaker, which at times made it difficult to see what was happening in the test tube containing the solution. Crystallization starts near the walls, and on the surface of the solution making it impossible to see if there is more than one set of crystallization temperatures for a mixture....   [tags: Chemistry]
:: 5 Works Cited
2006 words
(5.7 pages)
Powerful Essays [preview]
Sodium (Na) - Sodium (Na) Sodium has an atomic number of 11 and a mass of about 23g. It is a silvery white-metallic element classified under the alkali metals. Sodium has been known since early times and was used by the people of Mesopotamia and Egypt to make glasses. Sodium is the sixth most common element found on the earth. It is usually not found in nature but more often in compounds such as salt (NaCl). Sodium conducts heat and electricity easily. Without this element life could not exist. Each compound is used for a certain reason....   [tags: Science Chemistry] 732 words
(2.1 pages)
FREE Essays [view]
Magnetic Fluids - 1.1 PRELUDE: The phenomenon of ferromagnetism is associated only with the solid state of matter; like iron, nickel, cobalt and some rare earth metals and their alloys. Thus, up to now, there is no intrinsic homogeneous fluid having ferromagnetic properties; although, theories admit the possibility of ferromagnetism in the liquid state, and suggest that there is no inherent reason why they should not exist [1-3,5]. Ferromagnetism occurs when paramagnetic ions in a solid lock together in such a way that their spins all point (on the average) in the same direction ....   [tags: GCSE Chemistry] 1353 words
(3.9 pages)
FREE Essays [view]
The Chemical Weaponry Utilised In World War One and their Effects on Modern Ethics and Morals - ... Both the French and the German had creative ways to administer this gas. The French used the grenade, an already proven and trustworthy weapon, which was extremely effective in releasing the gas. The German army took advantage of its gaseous state as well, and used fragmentation shells against the British that also successfully diffused the gas. The use of this gas against each other resulted in an extremely controversial debate as to whether it breached the Hague Treaty of 1899, a treaty that banned the launching of projectiles containing asphyxiating gas or poisonous gas....   [tags: War, Chemistry]
:: 3 Works Cited
1563 words
(4.5 pages)
Powerful Essays [preview]
The Applications and Making of Artificial Diamonds - The Applications and Making of Artificial Diamonds Diamonds are very unique. Their hardness and beauty have enticed people for many years. Now some of the same attributes that make them appealing also make them useful. To understand these attributes the chemistry of carbon is very important. This unique chemistry is what makes them so hard to make. Much research has gone into the making of diamonds and this has led to many successes in the field. These discoveries have led to machines and processes that make diamond making more efficient and reliable....   [tags: Diamond Diamonds Chemistry Essays]
:: 1 Works Cited :: 7 Sources Cited
1578 words
(4.5 pages)
Strong Essays [preview]
Investigation to find the effect of concentration on the rate of reaction - Investigation to find the effect of concentration on the rate of reaction Aim --- I am going to investigate the effect of concentration on rate of reaction in the reaction between Sodium Thiosulphate and Hydrochloric Acid: 2HCl + Na2S2O3 à 2NaCl + SO2 + S + H2O Prediction I predict that that the greater the concentration of Sodium Thiosulphate or Hydrochloric Acid, the faster the rate of reaction. I think this because of the collision theory: Increased concentration = Increased number of molecules = number of collisions and, therefore, the rate of reaction....   [tags: GCSE Chemistry Coursework Investigation] 1596 words
(4.6 pages)
FREE Essays [view]
Primo Levi’s The Periodic Table - Primo Levi’s The Periodic Table Primo Levi’s personal relationship to his profession as a chemist shows that philosophically and psychologically, he is deeply invested in it. His book THe PeriOdic TaBLe shows that his methodology cannot be classified as either purely objective or purely subjective. He fits into the definition of dynamic objectivity given by Evelyn Fox Keller in her book Reflections on Gender and Science. Primo Levi’s methodology cannot be called purely objective. Being purely objective would mean being not influenced by personal beliefs or feelings....   [tags: Chemisty Chemistry Science Essays]
:: 2 Works Cited
1135 words
(3.2 pages)
Strong Essays [preview]
Lithium and Bipolar Disorder - Lithium and Bipolar Disorder INTRODUCTION The drug lithium has been used for a variety of disorders such as gout, diabetes, and epilepsy for over 100 years. It was not until 1949 when John Cade discovered that lithium had a calming effect on guinea pigs that the possibilities of it being used for mania were explored (Paykel, 1992). Since then, lithium has been established as one of the primary treatments for manic depression disorder. In the body of this paper we will explore the chemistry of lithium, the synaptic transmitters involved, the parts of the neuron affected, the inhibitory and excitatory potential changes, the ion channels effected, the physiological changes, the primary behavior changes, the side effect behavior changes and the effects reported by users....   [tags: Chemistry Chemical Essays]
:: 9 Works Cited :: 1 Sources Cited
1894 words
(5.4 pages)
Term Papers [preview]
Investigate the effect of temperature on the rate of reaction - To investigate the effect of temperature on the rate of reaction Background Information: Chemical reactions take place all the time at many different rates, some are incredibly fast like an explosion-where you get no time to see what's happening or like rusting which could take years before the iron is completely rusted. The rate of reaction is extremely important because you need to know how long before the end of the session or you may not get results in time. In living organisms it's vital that all the chemical reactions take place at the rates which supply the cells with the things they need exactly when they need them....   [tags: GCSE Chemistry Coursework Investigation] 3176 words
(9.1 pages)
Unrated Essays [preview]
Investigating the effect of temperature on the rate of reaction between sodiumthiosulphate and hydrochloric acid - Investigating the effect of temperature on the rate of reaction between sodiumthiosulphate and hydrochloric acid Planning My coursework for G.C.S.E Chemistry will be based on the rate of reaction. I will be investigating the effect of temperature on the rate of reaction and will analyze the reaction between sodium thiosulphate and hydrochloric acid at different temperatures to see the effect of heat. I will be reacting sodium thiosulphate with hydrochloric acid at different temperatures. I will place 50cm3 of sodium thiosulphate and 5cm3 of hydrochloric acid in one conical flask....   [tags: GCSE Chemistry Coursework Investigation] 460 words
(1.3 pages)
FREE Essays [view]
The Uses of Salt - The Uses of Salt Mineral halite, best known as common salt, has been one of the most abundant and used minerals over the centuries. It is essential for the human diet and is an important commercial chemical. Pure salt consists of two elements, which are sodium and chlorine [chloride]. Its chemical name is sodium chloride (NaCl). “In chemistry, common salt is one of a large number of electrolytic compounds classified as salts. The compound occurs as a mineral in the form of crystals and the forms of the crystals are generally cubic and are transparent.” (Encyclopedia Americana 163) Halite (sodium chloride) comes from the Greek “halos”, meaning salt and “lithos” meaning rock, and is better known as “rock salt”....   [tags: Chemistry Salts Essays]
:: 1 Works Cited :: 3 Sources Cited
610 words
(1.7 pages)
Unrated Essays [preview]
The K+ Channel Revisited - The K+ Channel Revisited Many scientists enter the field of neuroscience with a desire to understand how the human brain functions to create our actions. Some take a large approach and study reactions to stimulus in live animals. This approach leaves us still wanting to know about things that aren't a result of an outside stimulus. Other scientists take the minimalist approach and start by studying the exact mechanisms of individual cells of the brain. But, what good does that do us for everyday life....   [tags: Chemical Neuroscience Chemistry Papers]
:: 13 Sources Cited
1870 words
(5.3 pages)
FREE Essays [view]
Psilocybin and Body Changes - Psilocybin and Body Changes Physiological (Whole Body) Changes Psilocybin, the active psychotomimetic, hallucinogenic chemical found in the psilocybe genus of mushrooms, is absorbed through the mouth and stomach and is a monoamine-related substance (Levitt 1975, Grilly, 1998). This means that psilocybin's biochemical effects are mediated by changes in the activity of serotonin, dopamine, and norepinephrine in the central nervous system (made up of the brain and the spinal cord) primarily by way of 5HT2a receptors (Grilly 1998, Hasler 2003)....   [tags: Chemistry Chemical Drugs Papers]
:: 9 Works Cited
1772 words
(5.1 pages)
FREE Essays [view]
Caffeine - Caffeine Caffeine is the most-widely consumed psychoactive substance by human beings throughout the world (Reid, 2005). This report will detail its natural origins, chemical structure (as well as those of similar substances), and the methods and dosages in which it is rendered into its usable form. Additionally, this report will detail caffeine's various biological pathways within the human body, including access to the brain and various neurotransmitter pathways. Caffeine is a chemical that occurs naturally in over 100 plant species throughout the world (Steffen, 2000)....   [tags: Science Essays Scientific Chemistry] 2039 words
(5.8 pages)
FREE Essays [view]
Carbon Dioxide produced by Reaction between Hydrochloric Acid and Calcium Carbonate - Investigate the effect of changing the concentration of hydrochloric acid and the volume of carbon dioxide produced by a reaction between hydrochloric acid and marble chips (calcium carbonate). Chemistry Coursework To investigate the effect of changing the concentration of hydrochloric acid and the volume of carbon dioxide produced by a reaction between hydrochloric acid and marble chips (calcium carbonate) Planning experimental procedures Aim In this coursework I will be investigating to see how the concentration of acid affects the rate of reaction with marble chips....   [tags: GCSE Chemistry Coursework Investigation]
:: 2 Sources Cited
2527 words
(7.2 pages)
Unrated Essays [preview]
Investigating how the concentration of reactants affects the rate of reaction - Investigating how the concentration of reactants affects the rate of reaction Chemistry Coursework This experiment is aimed at investigating how the concentration of reactants affects the rate of reaction: The reaction between hydrochloric acid and magnesium will be used to investigate how different concentrations of the acid affect the rate of reaction. The gas produced from the reaction will be measured and used to display the average rate of reaction. The rate of reaction is a measure of how fast a reaction is going and how long it takes to complete....   [tags: GCSE Chemistry Coursework Investigation] 1990 words
(5.7 pages)
Better Essays [preview]
Investigation to find out if changes in concentration of acid affect the rate of a chemical reaction - Investigation to find out if changes in concentration of acid affect the rate of a chemical reaction PLANNING – Title – Investigation to find out if changes in concentration of acid affect the rate of a chemical reaction. Introduction – The rate of reaction can be defined as the speed at which a reaction takes place. The rate of reaction tells us how quickly a chemical reaction has happened. There are many things that can affect the rate of reaction, (some of these are shown in figure 1 below.) In this coursework I am going to investigate what effect the change in acid concentration has on a chemical reaction....   [tags: GCSE Chemistry Coursework Investigation] 2613 words
(7.5 pages)
FREE Essays [view]
Rate of Reaction Experiment - Sodium Thiosulphate and Hydrochloric Acid - Rate of Reaction Experiment - Sodium Thiosulphate and Hydrochloric Acid Plan Aim: Our aim of this experiment is see the effect of Sodium Thiosulphate and Hydrochloric Acid by testing different concentrations and looking at how it affects the rate of reaction. For my chemistry GCSE course work I am going to look at the factors that affect the rate of reaction. It can be changed by 4 main factors: Catalyst, Temperature, Surface area and Concentration. To increase the rate of a reaction you need to increase the number of successful collisions....   [tags: GCSE Chemistry Coursework Investigation] 1991 words
(5.7 pages)
FREE Essays [view]
How the concentration of an acid affects the rate of reaction on marble chips - How the concentration of an acid affects the rate of reaction on marble chips Background: These different speeds of reaction are referred to as their rates. The rate of reaction depends on how often and how hard the reacting particles collide with each other. Particles have to collide in order to react, and the have to collide hard enough as well. This is called the collision theory. When the temperature is increased the particles all move quicker. If they are moving quicker then they are going to have more collisions....   [tags: GCSE Chemistry Coursework Investigation] 1986 words
(5.7 pages)
FREE Essays [view]
An Investigation into the Enthalpies of the Combustion of Alcohols - An Investigation into the Enthalpies of the Combustion of Alcohols ================================================================== Planning My aim for this experiment is to see the energy produced from different alcohols. This investigation involves burning alcohol in the air. ‘GCSE Chemistry’ by B.Earl and L.D.R Wilford says that "alcohols form, another homologous series, with the general formula Cn H2n+1OH ". The alcohol reacts with the oxygen in the air to form the products water and carbon dioxide....   [tags: GCSE Chemistry Coursework Investigation] 3784 words
(10.8 pages)
Strong Essays [preview]
The electrolysis of copper sulphate solution and copper electrodes - The electrolysis of copper sulphate solution and copper electrodes Introduction: For my GCSE Chemistry assessment I will be investigating the electrolysis of copper sulphate solution with the copper (ii) plates. Aim: My intention for this observation is to find out how the current has an effect on the mass of copper deposited in the electrolysis of copper sulphate and copper (ii) plates. Safety Precautions: In this investigation I will make sure that everything is as safe as possible and that there are no chances of accidents occurring....   [tags: GCSE Chemistry Coursework Investigation] 1255 words
(3.6 pages)
Better Essays [preview]
Comparing the Enthalpy Changes of Combustion of Different Alcohols - Comparing the enthalpy changes of combustion of different alcohols Planning What are alcohols. ================== Alcohol is the common family name for the hydrocarbon group alkanols. They are part of a homologous series. At least one of the hydrogen groups in the molecule is replaced by an OH group. GRAPH Propane Propan-2-ol They are all organic compounds. The general formulas for the alcohols are: CnH(2n+1)OH Where n represents a number. The first and simplest member of the alkanols family is methanol....   [tags: GCSE Chemistry Coursework Investigation]
:: 5 Sources Cited
4536 words
(13 pages)
Strong Essays [preview]
An investigation of neutralization reactions - An investigation of neutralization reactions Aim Question : What is the effect of changing the concentration of an alkali, on the volume of acid needed to neutralise it, when acid is added to it. The plan is to use two acids (Hydrochloric & Sulphuric) and one alkali (Sodium Hydroxide). The reason I need to use two acids is; because the question applies to all acids and alkalis and to just use one of each would not enable me to come to a general conclusion. If there had been more time available, ideally I would have preferred to use two alkalis as well as two acids....   [tags: GCSE Chemistry Coursework Investigation]
:: 3 Sources Cited
1489 words
(4.3 pages)
Better Essays [preview]
The Effect of Catalyst an the Rate Of Reaction - The Effect of Catalyst an the Rate Of Reaction Chemistry Coursework Does The Number of Drops of Catalyst Effect The Rate Of Reaction Candidate Name: Ben Dodds Candidate Number: 7158 School: Oundle School Completion Date: Introduction We are studying the reaction between zinc and sulphuric acid, the reaction is catalysed by copper sulphate and this experiment is to test whether the amount of drops effect the rate of reaction. Word Equation Zinc(s) + Sulphuric acid(aq) à Hydrogen(g) + Zinc Sulphate(aq) Symbol Equation Zn + H2SO4 à H + ZnSO4 This reaction is catalysed by Copper sulphate (CuSO4) Ionic Equation - Cancel Spectator ion (SO42-) Zn + 2H+ à Zn2+ + H2 For this reaction to work there must be hard collisions between the zinc and the hydrogen ions (acidity ion) from the acid, The faster the harder and the more often the collisions happen so I predict the more catalyst the faster the reaction....   [tags: GCSE Chemistry Coursework Investigation] 1447 words
(4.1 pages)
Better Essays [preview]
Factors Affecting the Decomposition of Marble Buildings by Acid Rain - Factors Affecting the Decomposition of Marble Buildings by Acid Rain Background Acid Rain: Nitrogen acids and sulphur dioxides come out of tall chimneys and vehicles. These go into the air, and air currents carry the gases away, and they react with water vapour and oxygen. This produces H2SO4 (sulphuric acid) and HNO3 (nitric acid). The acids become part of a cloud, and it falls down to earth, as acid rain or snow. This can end up miles away from the original source. The acid rain removes nutrients from soil, so plants can not get to them, so this eventually kills surrounding die....   [tags: GCSE Chemistry Coursework Investigation] 1583 words
(4.5 pages)
FREE Essays [view]
How concentration affects the rate of reaction between Hydrochloric Acid and Sodium Thiosulphate - How concentration affects the rate of reaction between Hydrochloric Acid and Sodium Thiosulphate Chemistry Coursework How Concentration Affects a Reaction Aim: The aim of this experiment is to find out how concentration affects the rate of reaction between Hydrochloric Acid and Sodium Thiosulphate. Introduction: This experiment will be carried out by drawing a cross on a piece of paper and mixing hydrochloric acid and sodium thiosulphate together to see if the cross disappears. The concentration of hydrochloric acid would change every reaction to show that concentration effects a reaction....   [tags: GCSE Chemistry Coursework Investigation] 1294 words
(3.7 pages)
Better Essays [preview]
The Reaction Between Marble Chips and Hydrochloric Acid - Using the syringe method I am going to investigate the reaction between Marble chips and hydrochloric acid by measuring the volume of carbon dioxide formed. Chemistry Using the syringe method I am going to investigate the reaction between Marble chips and hydrochloric acid by measuring the volume of carbon dioxide formed. This reaction rate will tell me how fast or slow a chemical reaction is and there are four things that could affect this greatly they are- * Concentration-An increase in concentration means there are more particles....   [tags: Chemistry Lab Experiment] 818 words
(2.3 pages)
Unrated Essays [preview]
The History of the Elements and Periodic Table - Greek thinkers and early people noted around 400BC, that things are different from each other, and can be broken down into smaller groups. They used the words “element” and “atom” to describe different and the smallest parts of matter. For over 2000 years, the four “elements” of Earth, fire, water, and air were used to explain many stories of the world. Something had to of been done to organize our thoughts and observations of our elements. A method was needed by 1860 to organize the sixty elements known by scientists....   [tags: Chemistry, Science, research papers] 990 words
(2.8 pages)
Better Essays [preview]
Graham's Law - In chemistry and in physics, the movement of particles becomes very important. One way in which particles move is through effusion. The formula for the rate of effusion of gas molecules was developed by a chemist by the name of Thomas Graham in the 19th century. December 21, 1805�September 16, 1869. Thomas Graham was born in December of 1805 in Glasgow, Scotland. His father was a workman who desired that his son enter the Church of Scotland. However, Graham became a student at the University of Glasgow in 1819, where he became interested in the field of chemistry....   [tags: physics chemistry graham grahams law] 619 words
(1.8 pages)
FREE Essays [view]
The Rate of Reaction in the Reaction Between Hydrochloric Acid and Sodium Thiosulphate - To see how the concentration of acid affects the rate of reaction in the reaction between hydrochloric acid and sodium thiosulphate. Planning; Aim To see how the concentration of acid affects the rate of reaction in the reaction between hydrochloric acid and sodium thiosulphate. Background; All reactions occur because of the particles that make up the reactants will collide, and if they have sufficient energy, react forming or breaking bonds. All four methods of increasing the rate of reaction can be explained in terms of increasing the number of collisions....   [tags: Chemistry]
:: 8 Sources Cited
2300 words
(6.6 pages)
Unrated Essays [preview]
The Rate of the 'Reaction' Between Sodium Thiosulphate and Hydrochloric Acid - To see if the concentration of the acid will effect the rate of the 'reaction' between sodium Thiosulphate and Hydrochloric Acid. Scientific Knowledge: I already know that the rate of a reaction can be increased if there are more collisions between the different particles, to increase the number of collisions made, one or more of the following five factors can be changed; * More Heat- if there is more HEAT in a mixture, the particles will be moving QUCIKER and with more energy so there will be more collisions and a higher chance of success....   [tags: Chemistry] 1077 words
(3.1 pages)
FREE Essays [view]
What factors affect the rate of a chemical reaction - What factors affect the rate of a chemical reaction NaS O + 2HCl 2NaCl + H O + SO + S I will be trying to find out how concentration affects the reaction between thiosulphate and hydrochloric acid. Prediction: I think that if the amount of thiosulphate is increased and the amount of water is decreased then the reaction will take less time because the collision theory states that if the concentration is increased, the number of particles in the will also increase, therefore the chance of successful collisions is increased and this speeds up the rate of the reaction....   [tags: Chemistry] 614 words
(1.8 pages)
FREE Essays [view]
What factors affect the rate of reaction - What factors affect the rate of reaction I am going to measure the amount of hydrogen produced after the reaction between hydrochloric acid and magnesium. The amount of hydrogen produced by attaching a 100cm3 gas syringe to a clonical flask. As soon as the magnesium reacts with the hydrochloric acid the gas syringe will be attached to the conical flask and the stop watched started to see how long it takes for the amount of hydrogen produced. Diagram ======= I predict that the rate of reaction will decrease as the concentration of the hydrochloric acid decreases....   [tags: Chemistry] 505 words
(1.4 pages)
FREE Essays [view]
Second Law of Thermodynamics - The second law of thermodynamics involves the concept of entropy, an idea that explains disorder in our world. The concept of entropy associates useful matter and waste with low entropy and high entropy, respectively. In order to look at entropy, we must first define the system of interest. For the remainder of this paper, the system will be Earth. Many people believe that everything we use up can be recycled and reused if we can develop the appropriate technology. However, the Second Law makes it essentially impossible to achieve complete recycling....   [tags: Chemistry] 431 words
(1.2 pages)
Unrated Essays [preview]
Acids, Bases and Amphiprotic Substances in Water - PURPOSE To observe the effect of various aqueous solutions of acids, bases and amphiprotic substances on a number of indicators, and to record the approximate pH. To determine more accurate pH values for the solutions, using a calibrated pH meter or data logging equipment. APPARATUS The following materials are required in order to complete this experiment:  Semi-micro test tubes and test tube rack  Small dropper bottles of the following test solutions:  0.1M HCl, HNO3, H2SO4, CH3COOH  0.1M NH3, NaOH, KOH  Household cloudy ammonia  White vinegar  0.1 M NH4Cl, NaHCO3, NaHSO4, NaCl, NaNO3, Na2SO4, Ca(OH)2  Calibrated pH meter or data logging equipment for determining pH  Small dropper bottles of the following indicators: <ul> <li> Universal Indicator <li> Litmus <li> Phenolphthalein <li> Methyl orange <li> Water </ul> PROCEDURE Part A - THE EFFECT OF ACIDS AND BASES ON COMMON INDICATORS (a) Place six drops of deionised water, the acids H3PO4, HNO3, H2SO4, CH3COOH, and HCl, and the bases NH3, NaOH, KOH, household cloudy ammonia, white vinegar, and water in fresh, clean, separate semi-micro test tubes, and add 1-2 drops of the indicator under test....   [tags: Chemistry] 1620 words
(4.6 pages)
Better Essays [preview]
Acids and Bases - PURPOSE To investigate the reactions of a typical acid (dilute hydrochloric acid) with metals, metal oxides, carbonates and bases. APPARATUS The following materials in order to complete this experiment: <ul> <li> Dropper bottles containing 0.1M solutions of hydrochloric acid or limewater (calcium hydroxide) and sodium hydroxide. <li> Dropper bottle of bromothymol blue indicator <li> Small samples of the following metals: zinc, copper turnings, magnesium and iron <li> Copper (II) oxide powder <li> Magnesium oxide <li> Marble chips (calcium carbonate) <li> Sodium carbonate <li> 12 test tubes and test tube holder <li> Bunsen burner <li> Stopper or cork <li> Wax taper and matches </ul> PROCEDURE (a) REACTION WITH METALS <ol> <li value="1"> Place a small piece of magnesium ribbon in a test tube and add about 2mL of dilute HCL....   [tags: Chemistry] 1014 words
(2.9 pages)
Better Essays [preview]
Redox Reactions - To predict a number of redox reactions from a table of relative reactivities of some common oxidants and reductants, and then to check these predictions by experiment. APPARATUS The following materials are required in order to complete this experiment:<p>,,X Reaction palette or set of semi-micro test tubes and stand<p>,,X Clean plastic tray<p>,,X Latex gloves<p>,,X Goggles <p>,,X Set of small dropper bottles containing each of the following: <em>f</em>æ Freshly prepared FeSO4 <em>f</em>æ 0.1M FeCl3 solution <em>f</em>æ 1M sulfuric acid, H2SO4 <em>f</em>æ 0.1M H2O2 solution <em>f</em>æ 0.1M KSCN solution <em>f</em>æ 0.1M K3Fe(CN)6 <em>f</em>æ Freshly prepared 0.1M KI solution <em>f</em>æ 0.1M sulfurous acid solution, H2SO3 <em>f</em>æ 0.1M K2Cr2O7 <em>f</em>æ Freshly prepared starch solution....   [tags: Chemistry] 557 words
(1.6 pages)
Unrated Essays [preview]
Kinetic Production of Isoborneol through the Oxidation-reduction Sequences of Borneol - Through an oxidation-reduction reaction sequence, Borneol is converted to isoborneol. First, borneol is oxidized through a reaction with sodium hypochlorite at 400C to form camphor. When the camphor is then reduced by sodium borohydride, isoborneol is formed. The percent yeild of isoborneol collected was 56.4%, and the melting point range was found to be between 174.2-179.90C. Through analysis of the product through 1H NMR spectroscopy the percent purity is found to be 77.2% pure isoborneol. Introduction Oxidation-reduction reactions can be used to stereochemically control and produce many different organic molecules....   [tags: Chemistry] 635 words
(1.8 pages)
Unrated Essays [preview]
Cloning, Pros and Cons - The young couple sat in the waiting room of the doctor's office with their heads hung low. They mumbled between themselves, wondering what the doctor would say at this visit. It is their ump-teenth check-up to try and figure out why they have not been able to conceive a child for the past 5 years. The woman wants with all of her heart to give birth to a child of her very own. They wondered if the doctor could do anything else to help them. Would the dream of having a baby of the couple's own blood vanish....   [tags: Chemistry] 2997 words
(8.6 pages)
Better Essays [preview]
Shipwrecks, Corrosion and Conservation - <ol> <li value="9">6: Option - Shipwrecks, Corrosion and Conservation <li value="9">6.1: The chemical composition of the ocean implies its potential role as an electrolyte </ol> Identify the origins of the minerals in oceans as: <ul> <li> leaching by rainwater from terrestrial environments <li> hydrothermal vents in mid-ocean ridges </ul> Identify - recognise and name There are 2 major sources of the salts in seawater: <ol> <li value="1"> Leaching by rain and ground water. <li value="2"> Dissolution of salts by water passing through hydrothermal vents....   [tags: Chemistry] 3833 words
(11 pages)
Better Essays [preview]
Specific Heat Lab - Objective: The purpose of this lab was to calculate the specific heat of a metal cylinder Procedure: 1. The 100ml Graduated cylinder was filled with water and a rubber stopper. 2. The metal was placed in the Graduated cylinder, water displacement was found. 3. The beaker was filled with water and the metal was placed in the water. 4. The Bunsen burner was lit. 5. The water in the beaker was boiled using the Bunsen burner. 6. The Styrofoam cup was filled with approximately 100ml of water....   [tags: Chemistry] 357 words
(1 pages)
FREE Essays [view]
Density Lab - Objective: The objective of this lab was to calculate the densities of various objects using different techniques. Procedure: <ol> <li value="1"> The mass of the 100-ml. Graduated cylinder was measured without water or rubber stopper. <li value="2"> The mass of the 100-ml. Graduated cylinder was measured without water but with the rubber stopper. <li value="3"> The mass of the metal cylinder was measured. <li value="4"> The 100-ml. Graduated cylinder, with rubber stopper was filled with an amount of water....   [tags: Chemistry] 684 words
(2 pages)
Unrated Essays [preview]
Copper Sulfide? Who Knows? - Objective: The objective of this lab was to calculate the ratio of the copper sulfur compound to conclude whether the compound is made of copper I or II. Procedure: <ol> <li value="1"> A copper coil was twisted. <li value="2"> The mass of the copper coil was found. <li value="3"> The copper coil was placed in a crucible. <li value="4"> A sulfer powder was added to the crucible to cover the copper coil. <li value="5"> The cover was placed on the crucible. <li value="6"> The Bunsen burner was lit....   [tags: Chemistry] 580 words
(1.7 pages)
Better Essays [preview]
Percent Composition by Mass of Oxygen in Potassium Chlorate - % Composition By Mass of Oxygen in Potassium Chlorate Objective: The purpose of this lab was to calculate the percent composition by mass of oxygen in potassium chlorate. Procedure: 1.The mass of the crucible and the cover was measured. 2.KClO3 was added to the crucible. 3.The mass of the crucible, cover and KClO3 was measured. 4.MnO2 was added in the crucible. 5.The mass of the crucible, cover, KClO3 and MnO2 was measured. 6.The Bunsen Burner was lit. 7.The covered crucible was placed over the flame of the Bunsen Burner using a ring stand....   [tags: Chemistry] 359 words
(1 pages)
Unrated Essays [preview]
Rates of Chemical Reactions - RATES OF CHEMICAL REACTIONS REACTION ORDER FOR IODATE ION OBJECTIVE: <ol> <li value="1"> To determine the order of a KIO3-NaHSO3 reaction with respect to the iodate ion. <li value="2"> To determine a difference on the rate of the reaction when the solution is 10oC higher than a room temperature. </ol> BACKGROUND: The rate of a chemical reaction is the speed at which reactants are converted to products....   [tags: Chemistry] 979 words
(2.8 pages)
Better Essays [preview]
Determination of an Equilibrium Constant - OBJECTIVE: To determine the equilibrium constant for the following reaction: Fe3+(aq) + SCN-(aq) -----> Fe(SCN)2+(aq) BACKGROUND: In this experiment, the equilibrium constant, K, for the above reaction is given by the expression: K = [FeSCN 2+] [Fe 3+][SCN 1-] where the concentrations of the substances are those at equilibrium. The equilibrium concentrations of these substances will be determined and used to determine K....   [tags: Chemistry] 939 words
(2.7 pages)
Better Essays [preview]
Equilibrium Constant of an Ester Hydrolysis Reaction - The Equilibrium Constant of an Ester Hydrolysis Reaction Abstract The first step in determining the equilibrium constant of an ester hydrolysis reaction is to prepare five different reaction mixtures with the volume given in Table 1. the bottles have different mixtures of HCl, H2O, an unknown ester, and one bottle has alcohol. We will later determine the equilibrium constant for the reaction between the unknown ester and water to produce an unknown alcohol, and unknown acid....   [tags: Chemistry] 1197 words
(3.4 pages)
Better Essays [preview]
Determination of Cu2+ by Titration - Determination of Cu2+ by Titration Introduction: The purpose of this lab is to determine the concentration of copper ions in an unknown solution. Complexometric titration will be used to determine the concentration. A buret will be used to deliver the complexing agent to the unknown solution. Ethylenediaminetetraacetic acid will be used as the complexing reagent. An indicator, Murexide in our case, will be used to indicate the endpoint of the reaction. Theories and Concepts: The anion of the acid, EDTA4-, will complex to the metal....   [tags: Chemistry] 507 words
(1.4 pages)
Unrated Essays [preview]
Scientific Controversies - Facts and reasons cannot in most circumstances settle scientific controversies. The main issue is a matter of interpretation. One person can interpret data and observations differently from another person. This is where the problem lies. Pride and scientific interpretation can keep a controversy going even when facts and reasons may seem to prove one side false. Also, if there is more than model and those models each have some kind of positive evidence, then they each have a point to argue from....   [tags: Chemistry] 859 words
(2.5 pages)
Unrated Essays [preview]
Potentiometeric Titrations - Title: Potentiometric Titration Purpose: The purpose of this lab was to construct a titration curve by titrating Formic acid using a standardized sodium hydroxide (NaOH) and a pH meter through potentiometric titration. After the data for the rest of the class is collected, compare and contrast the equivalence points to see how the concentrations of the various acids affected the acids weakness and strength. Methods: Obtain 0.020 M of Formic Acid (HCCOOH). Calibrate the pH meter using the instructions for calibrating the pH meter in the appendix....   [tags: Chemistry] 1297 words
(3.7 pages)
Better Essays [preview]
Analysis of Carbon Dioxide CO2 - Analysis of Carbon Dioxide CO2 Carbon Dioxide (CO2) is a colorless gas, which was first discovered in 1577 by Van Helmont who detected it in the products of both fermentation and charcoal burning. CO2 is used in solid, liquid, and gas forms in a variety of industrial processes. These include: beverage carbonation, dry ice, welding and chemicals manufacturing. It is produced by the combustion of all carbonaceous fuels and can be recovered in an abundance of ways. It is widely used today as a by-product of synthetic ammonia production, fermentation, and from flue gases by absorption process....   [tags: Chemistry] 294 words
(0.8 pages)
FREE Essays [view]
Notes on Chemical Bonding - Chemical notes on bonding Ionic bonding - This occurs between metals and non metals - Fe2+/3+, Cu+/2+, Zn2+, No3- - Metals loose electrons, non metals gain electrons. - Ionic compounds conduct electricity when dissolved, but not when solid, they also have high m & b points due to strong giant 3d lattice. They are also soluble in water as they have a charge - Metal atoms always form positive charged electrons while non metals from negatively charged electrons Metallic Bonding - They conduct electricity due to a sea of delocalised electrons - They have a lattice of positive atoms....   [tags: Chemistry] 807 words
(2.3 pages)
FREE Essays [view]
Mentos Experiment - MENTOS + SODA = . Problem: Which brand of soda tested spews the most liquid when three Mentos are doped into a 2-liter of each brand. We know that the reaction between Mentos and soda is an explosion, but what we are trying to figure out is which brand causes the biggest reaction. Hypothesis: If three Mentos are dropped into a 2-liter of Diet Coke, Diet 7-Up, and Dr Thunder, then the Diet Coke will have the largest reaction to the Mentos. Materials: 1 pkg. Mint Mentos candies 2-liter Diet Coke 2-liter Diet 7-Up 2-liter Dr....   [tags: Chemistry] 604 words
(1.7 pages)
Better Essays [preview]
Limiting Reactant Lab Experiment Using Baking Soda and Vinegar - Baking Soda and Vinegar: Limiting Reactant Lab Background The limiting reactant of a chemical reaction is the substance that places an upper bound on the amount of product that the reaction can produce. The limiting reactant places this upper bound because the reaction must stop once all of the limiting reactant is consumed. If the relative amount of reactants is altered, then the limiting reactant may change accordingly. For example, a balanced chemical equation of a certain reaction specifies that an equal number of moles of two substances A and B is required....   [tags: chemistry] 1472 words
(4.2 pages)
Better Essays [preview]
Atomic Structure, Moles and Periodicity - Atomic structure, Moles and Periodicity The Periodic Table is guidance or map to access different elements specific information, such as: atomic mass, isotopic richness, nuclear spins, electronic configuration and the position of elements belong to which group and period in table. Over the past decades there were many Scientifics which help to improvement of Periodic table but few of them made the most influence and contribution on Periodic table such as : Johann Dobereiner ,John Newlands , Dmitri Mendeleev and Henry Moseley....   [tags: Chemistry]
:: 9 Works Cited
1193 words
(3.4 pages)
Better Essays [preview]
Hydrogen Bond - Polar molecules have a weak, partial negative and partial a positive charge. For example in water the negative charge is the oxygen atom and the positive the hydrogen atoms in the water. When water molecules are close together, the regions that are positively and negatively charged are attracted to the oppositely charged regions or nearby molecules. The dotted lines shown on the picture are called hydrogen bonds. Each water molecule is bonded to four other molecules. The hydrogen bonds that are created between the water molecules are some of the essential and unique properties of water....   [tags: Chemistry]
:: 3 Works Cited
494 words
(1.4 pages)
Better Essays [preview]
Liquid Crystals - We were all taught that there were four states of matter: Solids, Liquids, Gases, and Plasma, but some states of matter cannot be defined by one the these four. One of which are liquid crystals. These crystals have properties of both liquids and solids. They physically flow like liquids, but also share characteristics of crystalline solids. There is also more then one type of liquid crystals along with their different phases. Since they have so many properties, its no wonder how much we use them today....   [tags: Chemistry]
:: 8 Works Cited
973 words
(2.8 pages)
Strong Essays [preview]
Emulsion Studies - The system of primary interest in this study was water-in-diluted Athabasca bitumen films. Formation of very stable water-in-oil emulsions is a major challenge for recovery of bitumen from oil sand deposits in Alberta-Canada. Emulsion studies 14-17 and works on single emulsion films 18,19 have shown that emulsion and film stability depends on type of solvent and solvent to bitumen (S/B) ratio. Furthermore, it was found that film behavior changes dramatically at so called critical (S/B) ratio 20, which coincides with formation of asphaltenes precipitates in solutions....   [tags: Chemistry] 1497 words
(4.3 pages)
Powerful Essays [preview]
Intermolecular Forces - ... This resulted in the kinetic energy being absorbed into the liquid from the air surrounding the temperature probe, causing said air to drop in temperature, which was duly reported by the probe, and used to calculate the ?T of the liquid. In the case of 1-Butanol the ?T was very small, indeed smaller than any other liquid tested. It also took a very long time comparatively to reach its minimum, as opposed to a liquid with a high ?T like Methanol which was quite fast. An inverse relationship is found then between the ?T and the strength of the IMF of attraction; as the forces of attraction increase, the magnitude of the temperature decrease of the probe will decrease in turn....   [tags: Chemistry] 815 words
(2.3 pages)
Strong Essays [preview]
Nitinol - ... In the above chart, the bold materials are the final three materials that will be considered for selection as the coronary stent material. Based on materials currently used in stents as well as based upon the characteristics in the above table, the finalist were chosen; a more in-depth look at the selection process can be found in the selection section of the report. Below is a brief overview of the calculations used for the thickness of the stent and the amount of material to be used in the stent....   [tags: Chemistry] 935 words
(2.7 pages)
Strong Essays [preview]
Decomposing Hydrogen Peroxide - ... Activation energy is that which is required for a reaction to be initiated. In order for a reaction to occur, the atoms or molecules must collide with each other, and with enough kinetic energy to break the existing bonds, forming an “activated complex.” Once this has occurred, the new bonds of the product(s) may be formed and a discrete quantity of energy will either be released or contained within the new bonds(Chang 582). In a third pairing of these experiments, two trials with equal concentrations of reactants will be performed at different temperatures....   [tags: Chemistry]
:: 1 Works Cited
1958 words
(5.6 pages)
Powerful Essays [preview]
The Properties of Seawater - ... Major solids in ocean water usually come in two forms: chloride and halogen ions. Common chloride ions dissolved in ocean water include sodium chloride, calcium chloride, potassium chloride, and magnesium chloride. Common halogen ions dissolved in seawater include sodium fluoride and potassium iodide. The measure of the total mass of halogen ions in seawater is called chlorinity. The average chlorinity in seawater is about 19.2% which is equal to 34.7% seawater salinity. There are also substances that are not accounted for when measuring the salinity of ocean water....   [tags: Chemistry]
:: 5 Works Cited
1748 words
(5 pages)
Better Essays [preview]
Profile Peculiarities in Semiconductor Etching: Origins & Techniques for Elimination - ... As the slope of the mask is lowered, the degree of bowing increases and shifts higher in the feature. Bowing is also partially a charging effect. The electrons at the surface of the features are approximately isotropic, while the ions are clearly highly anisotropic. The mask – which is generally not conductive – charges up negatively while the vast majority of the positive ions enter the trench without impacting the mask. Depending on the magnitude of the charging of the mask, ion trajectories may be altered enough to be bent into the sidewall....   [tags: Chemistry] 1997 words
(5.7 pages)
Powerful Essays [preview]
The Knorr Synthesis of Pyrroles - ... The 1H-NMR spectrum of product 3 (fig. 2) shows obvious solvent impurity peaks at 3.73 ppm due to enthanol1 and 2.17 due to acetone1. However, if these are ignored the spectrum shows characteristic peaks of the product; the first of which are at 1.24 (3H) and 1.38 (3H) ppm and are due to the two methyl groups on the ester groups (C12 and C15, fig. 1)2, these partially cover the other small peaks due to ethanol at 1.25 and 1.32 ppm1. The next peaks due to the product are at large singlets at 2.51 (3H) and 2.56 (3H) ppm which correspond to the two methyl groups directly bonded to the pyrrole ring (C6 and C7)....   [tags: Chemistry] 978 words
(2.8 pages)
Strong Essays [preview]
Analysis of Kinetic Rate Constant and Oxygen-Inhibition-Effect in Acrylate/Epoxide Hybrid Systems Photopolymerization - ... The presence of the acrylate moiety will reduce the water and alcohol sensitivity of the cationic ring opening polymerization. Similarly, the presence of the epoxide moiety will reduce the oxygen inhibition effect plagued by the free radical reactions. 5,15 Studies have shown that the hybrid have addressed other shortcomings such as viscosity, shrinkage and adhesion in various applications.3,16 There remains a need to understand the properties of the hybrid systems, especially by contrasting the hybrid monomer molecule to the hybrid monomers in one formulation....   [tags: Chemistry ]
:: 20 Works Cited
4224 words
(12.1 pages)
Powerful Essays [preview]
Hybrid Photopolymerization - ... A ratioing method will be adopted as shown in Equation 1 to obtain conversion from the peak as a function of time. Conversion time profile can then be plotted for the free-radical and cationic equations. {{25 Cai,Ying 2009; 39 Monroe,Bruce 1993}} α=1-((A_rxn (t))⁄(A_ref (t)))/((A_rxn (0))⁄(A_ref (0))) (1) Where α is the degree of conversion, 1 Arxn(0) and 1 Arxn(t) are the peak of the reactive band before and after the reaction at time 0 to t respectively. Similarly, 1 Aref(0) and Aref(t) are the peak of the reference band before and after the reaction at time 0 to t respectively....   [tags: Chemistry] 2538 words
(7.3 pages)
Powerful Essays [preview]
Background Information on Nickel - ... However this method is not preferred because it can leave a poor final product and additionally the etch process does not guarantee high repeatability. The most common type of synthesis for nickel nanowires is called electrodeposition. As mentioned earlier Nickel is one of the few materials that exhibit magnetic properties. This physical property is the bases for its unique growth method known as electrochemical deposition. Electrochemical deposition, also known as electrodeposition, has been around for thousands of years....   [tags: Chemistry] 2325 words
(6.6 pages)
Powerful Essays [preview]
Activation of Zero-Valent Magnesium using Acetic Acid for the Degradation of Triacetone Triperoxide in Ethanol - ... The final concentrations of the acids used to activate the ZVMg are found in Table 2. The concentrations for each of the acids were estimated from the equilibrium concentration of hydronium ions from the particular acid in water (the exact hydronium ion concentration in EtOH were not calculated). The TATP degradation results for the different acids tested are found in Fig. 4. The short chain carboxylic acids had the greatest effect on the degradation of TATP even compared to those acids with lower pKa values with acetic acid being the most effective in enhancing the degradation rate of TATP using the ZVMg....   [tags: Chemistry]
:: 20 Works Cited
2677 words
(7.6 pages)
Research Papers [preview]
CuPc Molecules Absorbed on the TiO2(011) Surface - ... Hipps et al., J. Phys. Chem. 100, 11207 (1996).]). At this point, it is worth to notice the existence of several domain boundaries, molecule dislocations and vacancies in the 2nd layer (see Figure 6b). A structural model of the phase II is shown in Figure 7e. Phase I (structural model in Figure 7f) contains molecular rows of flat-lying molecules, which are running along the surface oxygen zigzag structure. The molecules are slightly rotated (by approximately 10°), supposedly to minimize the intermolecular interactions similarly to previously observed rotations on several templates (i....   [tags: Chemistry ] 1548 words
(4.4 pages)
Powerful Essays [preview]
The Behavior of PTCDA Molecules Absorbed on the TiO2(011) - ... Godlewski, J. Budzioch, M. Szymonski, Nanotechnology 19 (2008) 495304]. Furthermore, PTCDA molecule due to the presence of two outer anhydrate groups is chemically active and this activity may be additionally driven be the substrate temperature upon adsorption. In general, balancing between the adsorbate–substrate and adorbate-adsorbate interactions (both may include the chemical one), gives a rise to rather complicated, substrate temperature dependent behaviour of molecules during the evaporation procedure, including self-assembly into chains....   [tags: Chemistry] 844 words
(2.4 pages)
Better Essays [preview]
Chemical Composition of Glass - ... In general, transition metal ions can exist in multivalent states depending upon the base glass composition, melting temperature and time, and pressure conditions [6]. Among these elements, prime attention should be paid to iron [7]. The addition of iron oxide to the glasses was found to increase their chemical durability and to suppress the tendency for crystallization on cooling or reheating [8]. Thailand quartz sands are located in many areas, especially eastern and southern. Most of them are beach sand....   [tags: Chemistry] 1004 words
(2.9 pages)
Powerful Essays [preview]
Gas Equilibriums: Examples of Reversible Reactions - ... Each reactant and product is raised to the power of the appropriate stoichiometric coefficient (a, b, c or d) from the balanced chemical equation (i.e. the coefficients become the exponents). The equilibrium concentration constant can be used to find the equilibrium pressure constant. Example 1: It follows then that K1, the equilibrium constant for: at equilibrium, is the reciprocal of K2, because by the rule just given: at equilibrium, Example 2: It follows then that K1, the equilibrium constant for: N2O4 (g) 2NO2 (g) at equilibrium, is the reciprocal of K2, because by the rule just given: at equilibrium, The effects of the value of k on the production of products can be explained by: Q > K The products must decrease and the reactants will increase....   [tags: Chemistry ] 1662 words
(4.7 pages)
Powerful Essays [preview]
Myogenic Cell Lines - ... A significant induction of apoptotic cells, overlapping the frequencies of non viable cells, was already observed after 1h of H2O2 exposure for both C2C12 and L6C5 cells, reaching about 25% ± 4.1 and 27% ± 3.6 in C2C12 and L6C5 cells, respectively (p < 0.05 with respect the untreated cultures). After 24 hrs of H2O2 - treatment the apoptotic index was 39% (C2C12) and 49% (L6C5). The combination between hGH and H2O2 showed not statistical differences with respect the treatment with H2O2 alone, either for the cytotoxic and the apoptotic effects (Fig....   [tags: Chemistry] 725 words
(2.1 pages)
Better Essays [preview]
Mixture and Compound Differences - ... Element 2 Elements are substances that cannot be broken down further into simpler substances by chemical means. There are currently 103 known elements from which all matter that exists is made. And they each have their own atomic number based on how many protons are in their nucleus. Chemical compounds are created from combining a minimum of two elements together in exact proportions. Compounds can only be separated by a chemical reaction. The record of compounds on Earth is practically endless....   [tags: Chemistry ] 634 words
(1.8 pages)
Better Essays [preview]
The Mobility and Toxicity of Contaminants and Trace Elements in Low-Temperature Geochemical Environments - ... Fenter, M.L. Rivers, N.C. Sturchio, S.R. Sutton (Eds.), Mineralogical Society of America, Washington, DC, 2002, p. 1. [3] E.J. Elzinga and D.L. Sparks, Environ. Sci. Technol. 36 (2002), p. 1460. [4] D.G. Strawn and D.L. Sparks, J. Colloid Interface Sci. 216 (1999), p. 257. Abstract | PDF (151 K) | View Record in Scopus | Cited By in Scopus (92) [5] D. Peak, R.G. Ford and D.L. Sparks, J. Colloid Interface Sci. 218 (1999), p. 289. Abstract | PDF (141 K) | View Record in Scopus | Cited By in Scopus (132) [6] A.A....   [tags: Chemistry]
:: 18 Works Cited
1135 words
(3.2 pages)
Powerful Essays [preview]


Your search returned over 400 essays for "Chemistry". To narrow your search results, please add more search terms to your query.
[<< Previous] [1] [2] [3] [4] [5] [Next >>]



Copyright © 2000-2011 123HelpMe.com. All rights reserved. Terms of Service