Question

1. If half cell A has a standard reduction potential of E= -1.10 V and half cell B has a standard reduction potential of E= 0.65 V, which half-cell is the anode?

2. Which half cell has the higher potential energy?

3. Calculate Ecell for this voltaic cell.

Answer 1

A + e ==> A^- Eo = -1.10vb
B + e ==> B^- Eo = 0.65v
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For a spontaneous cell A must be reversed; therefore,
A^- ==> A + e E = 1.10
B + e ==> B^- E = 0.65
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A^- + B ==> A + B^-
Ecell = 1.10 + 0.65 = ?

The anode is where oxidation occurs and oxidation is the loss of electrons; therefore, A^- must be the anode.