Question

The Gibbs energy for the decomposition of Al₂O₃ at 500°C is as follows :

2/3 Al₂O₃ → 4/3 Al + O₂, Δ_rG = + 966 kJ mol^-1 

The potential difference needed for electrolytic reduction of Al₂O₃ at 500°C is at least

(1) 4.5 V 

(2) 3.0 V 

(3) 2.5 V 

(4) 5.0 V

Answer 1

Correct option(3) 2.5 V 

Explanation: