2013 Palmitos‚ Isabel Experiment # 2 chemical changes I. INTRODUCTION Chemical changes occur when a substance combines with another to form a new substance whether by combination reaction‚ combustion reaction‚ decomposition reaction and etc. These changes can be observed by evolutions of gas‚ appearance or disappearance of a precipitate‚ evolution or absorption of heat or even change in color. This experiment aims to observe the different chemical changes copper undergoes in different conditions
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activation energy for the iodine clock reaction Introduction: The iodine clock reaction is a presentation of chemical kinetics‚ which are the elements that affect the rate of chemical reactions. When the two colorless solutions are incorporated together‚ no reaction can be spotted. But after a short period of time‚ the solution turns into a dark blue solution. The term rate of reaction is stated as the decrease in the concentration of one of the reactions or the increase in the concentration of
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This assignment discusses chemical kinetics by determining the rate and average value for rate constant based on experimental values given. The orders of the reactants can only be determined experimentally‚ so we must look at how the concentration of the reactants affect the instantaneous initial rate while holding the concentration of the other reactant constant. In this reaction‚ the overall reaction order for the rate law is third because the order for A is second and the order for B is first
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Abstract We performed two trials of nine different variables of reactions to determine what increases/decreases reaction rates. The variables we used are hot/cold and room temperature water‚ a equal mixture of HCL and water‚ A equal mixture of NaOH and water‚ either a whole‚ broken‚ or finely crushed Alka-seltzer tablet. The fastest rate average was at 0.04 s (finely crushed Alka-seltzer with room temp. water). The slowest rate average is 8.02 s (Alka-seltzer with cold water). Introduction
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Chemestry Lab Rates of Reaction (Picture from: http://sciencespot.net/Pages/kdzchem.html) The rate of reaction is how fast or slow a reaction is completed. This is important for factories and chemists all over the world. What happenes during a reaction is atoms or molecules that collide and form new molecules. You can affect this rate of reaction with: temperature of reactants or suroundings‚ surface area of reactants‚ if there is a catalyst present‚ but in theis lab the concentration was changed
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The Diels-Alder Reaction Submitted by: Joe Student Partner: Jill Student Date: February 8‚ 2005 TA: Super TA Reaction +OOOxylene140 oCOOO Data Table Reagents MW Grams used Lit. Mp Anthracene 178.23 g/mol 1.023 g 216-218ºC Maleic anhydride 98.06 g/mol 0.497 g 54-56ºC Products MW Grams obtained Lit. Mp Observed Mp Crude product 276.29 g/mol 1.362 g 261-262ºC 260.2-261.3ºC Recryst. Product 276.29 g/mol 1.283 g 261-262ºC 261.3-261.9ºC Results and Discussion Discuss the
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reaction rates and concentration (research paper) By katie prestage what are reaction rates? The rate of reaction is the speed in which a reaction takes place. This can be measured by the rate in which a reactant is used up‚ or the rate a product is created. If a reaction has a low rate‚ it means that the particles are combining at a slow speed. If the rate is high‚ it means that the particles are coming together at a fast speed. For example‚ the rusting of iron through oxidation has a slow
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by Georg Wittig in 1954‚ the Wittig reaction is a robust organic synthesis method for preparing stereospecific alkenes. In general‚ Wittig reactions involve an aldehyde or ketone and a Wittig reagent (triphenylphosphonium ylide) and result in the formation of an alkene product and triphenylphosphine oxide (side product). Stereospecific alkene products can be synthesized by adjusting the reaction reagents and conditions. In the 60 years since the Wittig reaction was discovered‚ many articles have
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Enzymes are proteins which serve to reduce the activation energy required for biological reactions (Russell and others 2010). This allows biologically important chemical reactions to occur rapidly enough to allow cells to carry out their life processes (Russell and others 2010). Enzymes are made of one or more polypeptide strands‚ which individually or as an associated complex take on a three-dimensional shape. When properly associated‚ these shapes form the active site and other supporting structures
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and Results Did you observer any chemical changes in this experiment? Yes. CuCo2 turned green when I applied heat to it. B. What evidence did you use to decide that something was a chemical change? I viewed my other test tubes to see if it there was a chemical change in those. C. Give at least two examples of chemical changes you observed. Zn and MgO when I Diluted HCL D. Classify the following properties of sodium metal as physical or chemical: • Silver metallic color: Physical
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