Treat your data sets independently. Enter your data in two columns in a spreadsheet. Your goal is to plot In K vs. 1/T (remember to use the absolute temperature). To determine K, you need to calculate the concentrations of all species that appear in the equilibrium expression. Do this as follows: [COC142-]: Use Beer's Law to calculate this concentration ( = 572 L mol-1 cm-1). However, you need to "adjust" your measured absorbance. Since both compounds absorb at 692 nm, not all of the light absorbed is due to the blue, chloride species. A small amount is due to the pink, aquo complex. Fortunately, this is a small amount, but it becomes important when the concentration of the chloro complex is very low. To compensate, divide the absorbance of the [Co(H2O)6]2+ at 511 nm by 29 ( this is the ratio of the molar absorptivity of this complex at 512 nm to that at 692 nm) and subtract this value from every absorbance measurement in your data set.* Use this "adjusted" absorbance to calculate the CoC142- concentration. *Note that this approach assumes that the concentration of [Co(H20)6]2+ does not change. While this is not true, the relative change in concentration is small enough that it does not introduce significant error. [Co(H20)62+]: Use the total cobalt concentration of the solution and the concentration of the CoC142- to calculate [Co(H2O)6]2+ by the following equation:[Co2 +Jtotal [CoC142-]+[Co(H2 0)62+] [CI]: Assume this to be 4.0, the molarity of the acid solvent, at all temperatures, i.e., assume that the change in chloride concentration is negligible as the reaction progresses. Using these three concentrations, calculate K for each temperature. Is it increasing or decreasing? Why? Prepare a graph of In K vs. 1/T and calculate EH and S. Repeat the analysis for your second data set. Average your two values for each quantity. Post-Lab Questions 1. Using your values of H and IIS, explain the temperature dependence of the equilibrium constant for your reaction using LeChatelier' s Principle. 2. From a molecular level, interpret the S value for the reaction. THE TEMPERATURES ARE 10-90 CELSIUS AND THE ABSORBANCE CAN BE MADE UP NUMBERS
Treat your data sets independently. Enter your data in two columns in a spreadsheet. Your goal is to plot In K vs. 1/T (remember to use the absolute temperature). To determine K, you need to calculate the concentrations of all species that appear in the equilibrium expression. Do this as follows: [COC142-]: Use Beer's Law to calculate this concentration ( = 572 L mol-1 cm-1). However, you need to "adjust" your measured absorbance. Since both compounds absorb at 692 nm, not all of the light absorbed is due to the blue, chloride species. A small amount is due to the pink, aquo complex. Fortunately, this is a small amount, but it becomes important when the concentration of the chloro complex is very low. To compensate, divide the absorbance of the [Co(H2O)6]2+ at 511 nm by 29 ( this is the ratio of the molar absorptivity of this complex at 512 nm to that at 692 nm) and subtract this value from every absorbance measurement in your data set.* Use this "adjusted" absorbance to calculate the CoC142- concentration. *Note that this approach assumes that the concentration of [Co(H20)6]2+ does not change. While this is not true, the relative change in concentration is small enough that it does not introduce significant error. [Co(H20)62+]: Use the total cobalt concentration of the solution and the concentration of the CoC142- to calculate [Co(H2O)6]2+ by the following equation:[Co2 +Jtotal [CoC142-]+[Co(H2 0)62+] [CI]: Assume this to be 4.0, the molarity of the acid solvent, at all temperatures, i.e., assume that the change in chloride concentration is negligible as the reaction progresses. Using these three concentrations, calculate K for each temperature. Is it increasing or decreasing? Why? Prepare a graph of In K vs. 1/T and calculate EH and S. Repeat the analysis for your second data set. Average your two values for each quantity. Post-Lab Questions 1. Using your values of H and IIS, explain the temperature dependence of the equilibrium constant for your reaction using LeChatelier' s Principle. 2. From a molecular level, interpret the S value for the reaction. THE TEMPERATURES ARE 10-90 CELSIUS AND THE ABSORBANCE CAN BE MADE UP NUMBERS
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
Related questions
Question
AI-Generated Solution
AI-generated content may present inaccurate or offensive content that does not represent bartleby’s views.
Unlock instant AI solutions
Tap the button
to generate a solution
Recommended textbooks for you
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY