MAKING A BATTERY- ELECTROCHEMICAL CELLS EXPERIMENT 12 POST-LAB QUESTIONS: Includ
ID: 528864 • Letter: M
Question
MAKING A BATTERY- ELECTROCHEMICAL CELLS EXPERIMENT 12 POST-LAB QUESTIONS: Include a discussion of the following topics in your written report. 1. You measured E for one of the voltaic cells in Part I. Calculate the corresponding values of AG and K for your cell. Since your reaction was spontaneous, what types of values would you expect for E AG, and K? 2. How do the class' values of SRP for each of the voltaic cells compare with the reported values? Give reasons for why some of the values may be higher or lower than the expected value. 3. hat are some other ways you might measure the concentration of an unknown co solution? Discuss the advantages and/or disadvantages of using the concentration cell.Explanation / Answer
1. Representative calculation,
With Pb/Cu cell
Ecell = 0.528 V
dG = -nFEo = -2 x 96500 x 0.528/1000 = -101.904 kJ
dG = RTlnK
So,
-101.904 x 10^3 = 8.314 x 298 lnK
K = 7.29 x 10^11
Thus, with spontaneous reaction, values of Ecell is +ve, K is positive and dG would be -ve.
2. The calculated values vary and are not found very close to the expected cell potentials
3. Other methods to measure the concentration of copper in solution, would be to do a titration experiment, wherein copper is complexed first and then the excess complexing agent is back titrated to determine the amount of it that has reacted with copper. The method is time consuming unlike using nernst equation but accurate.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.