20. Electrochemistry

What is the gibbs free energy change for the given reaction at 25ºC? 

 Au³⁺ (aq) + 3 Li (s)  →. Au (s) + 3 Li⁺ (aq)

Given the following reduction potentials: 

Au³⁺(aq) + 3 e^–  →. Au (s)                         E°_red = + 1.50 Volts

Li⁺ (aq) + e^–  →. Li (s)                                E°_red = – 3.04 Volts

The reduction of chlorate is given by the equation: 

ClO₃^– (aq) + 6 H₃O⁺ (aq) → Cl ^– (aq) + 9 H₂O (l)

If the standard cell potential is given as 1.373 V, how many electrons are transferred under standard conditions?

Calculate ∆Gr°xn and K for each reaction.

a. The disproportionation of Mn2+(aq) to Mn(s) and MnO2(s) in acid solution at 25 °C.

The silver oxide–zinc battery used in watches delivers a voltage of 1.60 V. Calculate the free-energy change (in kilo-joules) for the cell reaction <IMAGE>

Calculate the standard cell potential and the standard free-energy change (in kilojoules) for the reaction below. (See Appendix D for standard reduction potentials.) <QUESTION REFERENCES APPENDIX D> <IMAGE>

We've said that the +1 oxidation state is uncommon for indium but is the most stable state for thallium. Verify this statement by calculating E ° and ΔG ° (in kilojoules) for the disproportionation reaction

3 M+1aq2S M3+1aq2 + 2 M1s2 M = In or Tl

Is disproportionation a spontaneous reaction for In+ and/orTl+? Standard reduction potentials for the relevant halfreactions are

In3+1aq2 + 2 e- S In+1aq2 E° = -0.44 V

In+1aq2 + e- S In1s2 E° = -0.14 V

Tl3+1aq2 + 2 e- S Tl+1aq2 E° = +1.25 V

Tl+1aq2 + e- S Tl1s2 E° = -0.34 V