Balance Equation and Determine Cell Potential

Question

Give the overall balanced equation, and determine the cell potential for the following cell. Determine if the the reaction occurs spontaneously.

Mn+2 +2e− →Mn ε°=−1.18 V

Fe+3 +3e− →Fe ε°=−0.036 V

Answer 1

Mn+2 +2e− →Mn ε°=−1.18 V (anode) x 3

Fe+3 + 3e− →Fe ε°=−0.036 V (cathode) x 2

2Fe³⁺ + 3Mn ==> 2Fe + 3Mn²⁺

E = -.036 - (-1.18) = +0.82 V

It would be spontaneous since voltage is positive.