Interpretation:
The value of Gibb’s free energy for given cell reaction has to be calculated.
Concept introduction:
Standard reduction potential: The voltage associated with a reduction reaction at an electrode when all solutes are 1M and all gases are at 1 atm. The hydrogen electrode is called the standard hydrogen electrode (SHE).
Standard emf: Eocell is composed of a contribution from the anode and a contribution from the cathode is given by,
Where both
The change in free-energy represents the maximum amount of useful work that can be obtained in a reaction:
Relation between
Relation between
Want to see the full answer?
Check out a sample textbook solutionChapter 18 Solutions
Chemistry
- The standard potential, E, for the reaction of Zn(s) and Cl2(g) is +2.12 V. What is the standard free energy change, rG, for the reaction?arrow_forwardCalculate K at 25°C for each of the reactions referred to in Question 32. Assume smallest whole-number coefficients.arrow_forwardCalculate G at 355 K for each of the reactions in Question 17. State whether the reactions are spontaneous.arrow_forward
- Calculate E°, G°, and K at 25°C for the reaction 3Mn2+(aq)+2MnO4(aq)+2H2O5MnO2(s)+4H+(aq)arrow_forwardCalculate E°, G°, and K at 25°C for the reaction 3MnO4(aq)+4H+(aq)+Cl2(g)2Mn2+(aq)+2ClO3(aq)+2H2Oarrow_forwardThe equilibrium constant for a reaction is 31015 (a) Without carrying out any calculation, discuss whether ?G° for the reaction is positive or negative. (b) Calculate ?G° for this reaction.arrow_forward
- Given the following standard free energies at 25°C for the following reactions: N2O5(g)2NO(g)+32O2(g)G=59.2kJNO(g)+12O2(g)NO2(g)G=35.6kJ Calculate G° at 25°C for the following reaction: 2NO2(g)+12O2(g)N2O5(g)arrow_forwardThe overall reaction and equilibrium constant value for a hydrogen-oxygen fuel cell at 298 K is 2H2(g)+O2(g)2H2O(l)K=1.281083 a. Calculate and G at 298 K for the fuel cell reaction. b. Predict the signs of H and S for the fuel cell reaction. c. As temperature increases, does the maximum amount of work obtained from the fuel cell reaction increase, decrease, or remain the same? Explain.arrow_forwardCalculate G° at 25°C for each of the reactions referred to in Question 30. Assume smallest whole-number coefficients.arrow_forward
- Calculate the standard cell potential of the cell corresponding to the oxidation of oxalic acid, H2C2O4, by permanganate ion. MnO4. 5H2C2O4(aq)+2MnO4(aq)+6H+(aq)10CO2(g)+2Mn2+(aq)+8H2O(l) See Appendix C for free energies of formation: Gf for H2C2O4(aq) is 698 kJ.arrow_forwarda Calculate K1, at 25C for phosphoric acid: H3PO4(aq)H+(aq)+H2PO4(aq) b Which thermodynamic factor is the most significant in accounting for the fact that phosphoric acid is a weak acid? Why ?arrow_forwardFor each reaction listed, determine its standard cell potential at 25 C and whether the reaction is spontaneous at standard conditions. (a) Mn(s)+Ni2+(aq)Mn2+(aq)+Ni(s) (b) 3Cu2+(aq)+2Al(s)2Al3+(aq)+3Cu(s) (c) Na(s)+LiNO3(aq)NaNO3(aq)+Li(s) (d) Ca(NO3)2(aq)+Ba(s)Ba(NO3)2(aq)+Ca(s)arrow_forward
- Chemistry: An Atoms First ApproachChemistryISBN:9781305079243Author:Steven S. Zumdahl, Susan A. ZumdahlPublisher:Cengage LearningChemistryChemistryISBN:9781305957404Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCostePublisher:Cengage Learning
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry: Principles and PracticeChemistryISBN:9780534420123Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward MercerPublisher:Cengage LearningChemistry: The Molecular ScienceChemistryISBN:9781285199047Author:John W. Moore, Conrad L. StanitskiPublisher:Cengage Learning