ABSTRACT: The purpose of this experiment was to determine the rate constants and ionic strengths of the series and to prove the Bronsted relation. In order to do so, known amounts of KI, Na2S2O3, KNO3, EDTA, starch and K2S2O8 were mixed up, and placed in the spectrophotometer until the %T reached 60%, and time was recorded. In the first part of the calculations, for flask 1, 2 and 3, the true reaction rate was calculated using the equation k = (1/∆t) x ([S2O32-]/[Iodine][S2O82-]). Which resulted in values of 2.8878765.66 x 10-3 s-1 , 3.159845 x 10-3 s-1, and 3.079703 x 10-3 s-1, these values are all similar to each other since they contain no electrolyte reacting with the persulfate solution. The apparent reaction rate was calculated using the equation, kapp= (1/∆t) x ([S2O32-]/[S2O82-]) which resulted in apparent rate constants of 5.66 x 10-5 s-1, 6.1958 x 10-5 s-1, 6.0356 x 10-5 s-1.
All of these situations call for proper hand washing technique. Hands should be washed periodically during the day to prevent the risk of illness or infection. Proper hand washing technique begins with preparation. During the preparation remove jewelry, including watches. Jewelry has small crevices that can hold microorganisms.
One of the important aspects of organic chemistry is being able to take an impure mixture of organic molecules, identify it as a mixture and purify each component. In this lab, we will explore several methods of the identification and purification of organic compounds. As these methods will be used throughout the semester, it is important that you learn how to effectively use these methods. Purpose of Experiment 1. Identify that your Excedrin is a mixture of organic molecules using thin layer chromatography (TLC), melting point (mp) and Proton Nuclear Magnetic Resonance Spectroscopy (1H-NMR).
Experiment 8 : Ramen Spectroscopy Objective: To utilize Raman Spectroscopy as an analytical chemistry tool to determine (i) the composition of an unknown chloroform/benzene mixture (ii) the amount of ethanol in vodka. Pre-lab questions: 1) What is a calibration curve and how would you go about constructing one? A calibration curve shows the response of an analytical method to known quantities of an analyte. To construct a calibration curve, we first prepare known samples of the analyte covering a range of concentrations expected for the unknowns and measure the response of the analytical procedures of these standards to generate signal data. After the measurement is done, a linear graph of the signal data against analyte concentration is plotted.
Determination of the pKa of Methyl Red by UV-Vis Spectroscopy February 16, 2010 (Partner:) ABSTRACT The purpose of this experiment was to obtain the pKa for an acid-base indicator. A spectrometer was used to determine the pKa of methyl red. The calibration curves were created by analyzing samples of known concentration at pH’s well above and below the pH indicator range for methyl red. Then samples of known pH were analyzed. By, solving the system of equations using linear algebra, the concentrations of the indicator and the conjugate base were determined.
Abstract: Gravimetric analysis can be used to determine the percentage of phosphorus in plant food. A precipitant of known composition is produced and weighed to find percent of phosphorus in compound. From the mass and known composition of the precipitate, the amount of original ion can be determined. Introduction: Gravimetric analysis is based on the measurement of mass. Gravimetric analysis involves isolation of an ion in solution by a precipitation reaction, filtering, washing the precipitate free of contaminants, conversion of the precipitate to a product of known composition, and finally weighing the precipitate and determining its mass by difference.
Nathan Bahn Beer’s Law Study Lab Introduction: In this lab, we used a spectrometer to observe the transmittance of light at a certain wave length. We experimented to see if the molarity of a solution changes the transmittance of light and the absorbance of that light by the solution. By observing the percent transmittance and the amount of light absorbed, we can calculate the amount of color absorbing components in the solution. Through this process is how we are able to discover the amount of copper in the solution. Experimental Procedure: 250 mL of the copper solution was made by creating 100 mL of the solution, reacting CuO with HNO3, and then diluting to the mark of 250 mL.
We can manipulate the substrate concentration by varying the concentration of H2O2 taken during each trial of the experiment and measure the rate of reaction by measuring the time taken for the paper disc to float to the surface. Hypothesis: The predicted results of
How to wash your hands Washing your hands properly is an easy way to avoid getting and spreading viruses and germs. First, remove all rings, watches, bracelets, or other jewelry on hands and wrists. Jewelry can carry pathogens and should be cleaned with a disinfectant separately, so they will not be damaged. Next, stand close enough to the sink to reach the flow of water without touching the sink with your body because the sink itself should be considered contaminated. By standing too close to the sink it may spread any contamination to your cloths.
We are looking to find wether the reaction is exothermic or endothermic. Experiment 2: the aim for this experiment is to record the pH level of a sodium hydroxide and hydrochloric acid reaction. Then record it into the graph, it should resemble the standard neutralization curve, as shown under the introduction. Materials: what you will need for both experiments: Experiment 1: ➢ 20g baking soda ➢ 20g citric acid ➢ 2 cm strip of magnesium ➢ 50 ml of 5M HCl acid ➢ 50 ml measuring cylinder ➢