Question

Consider the reaction of iodine with manganese dioxide

3I₂(s) + 2MnO₂(s) + 8OH^-(aq)  ↔ 6I^-(aq) + 2MnO₄^-(aq) + 4H₂O(l)

The equilibrium constant for the overall reaction is 8.30 x 10^-7. Calculate ΔG° for the reaction at 25° C.

1. -15.1 kJ
2. -34.7 kJ
3. 15.1 kJ 
4. 34.7 kJ

Answer 1

ΔG° =−2.303RTlogK

= 2.303×8.314×298log8.13×10^-7

= 5705 × -6.08991

= -34.7kJ