Hydrogen Peroxide Concentration Effect on Thiosulfate Reaction Rate, Essays (university) of Chemistry

Download Hydrogen Peroxide Concentration Effect on Thiosulfate Reaction Rate and more Essays (university) Chemistry in PDF only on Docsity! Analysis of Kinetics Joshua Scognamillo October 16, 2020 University of Central Florida Introduction Kinetics is a subfield of chemistry that aims to determine rates of chemical reactions, which will be seen in the analyzed experiment in this lab report. In simple terms, kinetics is an analysis of how quickly a reaction will occur once all the reagents are added and what product is observed as a result. This can be observed in everyday life such as adding hydrogen peroxide to a wound and watching it bubble or seeing leaves on a tree change color as the seasons change. These examples show how a chemical change can be observed, but scientists are more concerned with the effectiveness of a reaction and kinetics can help enable them to manipulate reactions to get a desired product more efficiently. The goal of this experiment is to determine how quickly thiosulfate ions will react with varying concentration of hydrogen peroxide in a solution. Although the indication of a chemical reaction in this experiment is merely a color change, understanding principles like rate of reaction, which is the speed at which a reaction occurs determined by a single product, will enable those to take these applications and use them in more practical settings, such as determining rate of metabolism for a new drug or determining how plants can metabolize certain fertilizers. It is also important to know how increasing or decreasing the concentration of a reactant or product can cause equilibrium to shift towards products or reactant. Taking an antacid would be an example of decreasing the acidity of the stomach and buffering the acid to prevent things like acid reflux, and taking more (increasing the concentration) would yield a more desirable result up to a certain point [1]. Having a grasp of these core chemistry topics is vital to understand the methods of the experiment and aid in data interpretation. Experimental Methods Three 100 mL beakers, volumetric pipets, a stopwatch, a stir plate with a magnetic stirrer, and 4 beakers containing 100 mM of iodine ion (solution 1), 20.1 mM of thiosulfate ion (solution 2), and 174 mM of hydrogen peroxide (solution 3) along with distilled water were each put into their own respective beakers. The experiment was performed three times, each with a consistent concentration of thiosulfate ion and iodine ion so the effect of varying hydrogen peroxide and distilled water concentrations could be determined based on time taken to observe a color change. For each experiment, 10 mL of solution 1 was added to a clean beaker along with 1 mL of solution 2. The beakers were then placed on the stir plate one at a time and then distilled water was added as necessary, then the magnetic stir bar was added, and the plate was turned on. As the solution was being stirred, solution 3 and distilled water was added. 0 mL, 2.5 mL and 5.0 mL of distilled water were added before hydrogen peroxide for experiments 1-3 respectively. For each experiment, volumes of 10. mL, 7.5 mL, and 5.0 mL of solution 3 were added to the beakers containing the combination of solutions 1 and 2. Once solution 3 was added to the solutions, the stopwatch was started, and a color change would indicate that the stopwatch needed to be paused. The stopwatch was then reset and prepared for the other 2 experiments. The times it took for each solution to turn blue were written down in a table. Along with this information was the relative concentrations of the ions in the final solution which was found by calculating the starting concentration of each solution and of the beaker, affecting the results of the trials. Another source of error could have occurred when stopping the stopwatch because the reaction time may not have been as quickly as desired, thus leading to a different calculation of initial rates. Although these are small errors, it is important to be precise when performing experiments. Based on the results of the experiment, it is assumed that addition of certain chemicals to a solution can lead to a desired chemical change, and manipulation of concentrations of reactants and products can lead to a faster or slower reaction. The basis of this experiment illustrates how kinetics can be used in other fields of science. Researches often study metabolism and how quickly the body breaks down certain drugs, so these researches can use kinetics to study how quickly different body types can break down a drug, allowing them to make informed decisions on how much a person should take and how often. Developments with kinetics are vital to the health and safety of others. Works Cited [1] Senese, F. (2018, February 23). What are everyday examples of temperature effects on reaction rate? Retrieved October 16, 2020, from https://antoine.frostburg.edu/chem/senese/101/kinetics/faq/everyday-kinetics.shtml