Answer to Question #110496 in General Chemistry for Emma

Question

Consider a Voltaic so made up of copper and sodium half cells. Write the half reactions, the balanced overall reactions, and determine the cell potential under standard conditions is this reaction spontaneous or nonspontaneous

Answer 1

Half-reactions:

cathode: Cu²⁺ + 2 e^- = Cu

anode: Na - e^- = Na⁺

Overall:

Cu²⁺ + 2 Na = Cu + 2 Na⁺ (ionic form)

CuCl₂ + 2 Na = Cu + 2 NaCl (example of complete form)

Cell standard potential:

E⁰ = E⁰(Cu²⁺/Cu) - E⁰(Na⁺/Na) = 0.337 + 2.710 = 3.047 V

Reaction is spontaneous in the forward direction (because E⁰ > 0).