PChemII Lab 2
CHEM 4104
Physical Chemistry II
Report 1: The Kinetics of a Reversible, First-Order, Consecutive Reaction: The Reduction of Cr(VI) by Glutathione
By: Hector Sepulveda
ID:900105300
University of Texas at the Permian Basin
Abstract
In the experiment the reduction of Cr(VI) by glutathione will be monitored, the data will be recorded and the double-exponential dependence of the reaction will be analyzed. Exponential stripping, as well as computer assisted non-linear regression analysis will be utilized to determine the rate equation as well as the rate constants of the reaction.
Introduction
Many biochemical reactions and their rates cannot be simply described by basic kinetics such as first or second order.1 Many are very complex with multiple steps as well and reversible reactions and intermediates, the description of such processes can often take the form of complex equations and can require the aid of computer data analysis and programs in order to interpret the acquired experimental data. Materials and Methodology
Twenty milliliters of eight millimolar solution of GSH were poured into a beaker and mixed with four-tenths molar dipotassium phosphate buffer as well as six milliliters of hydrochloric acid. The pH was then measures and adjusted with sodium Hydroxide until the pH was six. Three milliliters of the solution was then pipetted into a one centimeter path length spectrophotometer sample cell, and then two hundred microliters of one and six-tenths millimolar solution were pipetted into the cells as well. The absorbance was recorded every five seconds for approximately two thousand seven hundred seconds or forty-five minutes. The data for the absorbance at three hundred and seventy nanometers as well as four hundred and thirty nanometers was recorded and plotted on a scatter plot. The data was then subjected to exponential stripping as well as non-linear regression analysis in order to determine the rate constants for the reaction and to
Physical Chemistry II
Report 1: The Kinetics of a Reversible, First-Order, Consecutive Reaction: The Reduction of Cr(VI) by Glutathione
By: Hector Sepulveda
ID:900105300
University of Texas at the Permian Basin
Abstract
In the experiment the reduction of Cr(VI) by glutathione will be monitored, the data will be recorded and the double-exponential dependence of the reaction will be analyzed. Exponential stripping, as well as computer assisted non-linear regression analysis will be utilized to determine the rate equation as well as the rate constants of the reaction.
Introduction
Many biochemical reactions and their rates cannot be simply described by basic kinetics such as first or second order.1 Many are very complex with multiple steps as well and reversible reactions and intermediates, the description of such processes can often take the form of complex equations and can require the aid of computer data analysis and programs in order to interpret the acquired experimental data. Materials and Methodology
Twenty milliliters of eight millimolar solution of GSH were poured into a beaker and mixed with four-tenths molar dipotassium phosphate buffer as well as six milliliters of hydrochloric acid. The pH was then measures and adjusted with sodium Hydroxide until the pH was six. Three milliliters of the solution was then pipetted into a one centimeter path length spectrophotometer sample cell, and then two hundred microliters of one and six-tenths millimolar solution were pipetted into the cells as well. The absorbance was recorded every five seconds for approximately two thousand seven hundred seconds or forty-five minutes. The data for the absorbance at three hundred and seventy nanometers as well as four hundred and thirty nanometers was recorded and plotted on a scatter plot. The data was then subjected to exponential stripping as well as non-linear regression analysis in order to determine the rate constants for the reaction and to
References: 1. Halpern, A., & McBane, G. (2006). Experimental physical chemistry: A laboratory textbook.(3rd ed.). New York: W.H. Freeman.