Question

9 part 6

Calculate the standard cell potential for each of the following electrochemical cells

Part A

Ni2+(aq)+Mg(s)→Ni(s)+Mg2+(aq)

Part B

2H+(aq)+Fe(s)→H2(g)+Fe2+(aq)

Express your answer using two significant figures.

Part C

2NO−3(aq)+8H+(aq)+3Cu(s)→2NO(g)+4H2O(l)+3Cu2+(aq)

Express your answer using two significant figures.

Answer 1

Part A

Mg(s) ---------------> Mg^2+ (aq) + 2e^-       E0   = 2.38v

Ni^2+ (aq) + 2e^- -------> Ni(s)                     E0 = -0.23v

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Ni2+(aq)+Mg(s)---------->Ni(s)+Mg2+(aq)   E0cell = 2.15v

Part B

Fe(s) -----------------> Fe^2+ (aq) + 2e^-             E0 = 0.41v

2H^+ (aq) + 2e^- ---------> H2(g)                         E0 = 0.00v

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2H+(aq)+Fe(s)---------->H2(g)+Fe2+(aq)         E0cell = 0.41v

Part C

3Cu(s) ---------------------------> 3Cu^2+ (aq) + 6e^-                E0 = -0.34v

2NO3^- + 8H^+ (aq) +6e^- -------> 2NO(g) + 4H2O(l)              E0 = 0.96v

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2NO3^-(aq)+8H+(aq)+3Cu(s)---->2NO(g)+4H2O(l)+3Cu2+(aq) E0cell = 0.62v