Question

6. If E1 = 0.5 V corresponds to Cr3+ + 3e– Cr(s) and E2 = 0.41

Vcorresponds to Cr3+ + e Cr2+ reactions, calculate the emf(E3) of the

reaction Cr2+ + 2e Cr(s)​

Answer 1

Answer:0.95

Explanation:G°=nFE°

G3=G1+G2

-n3FE°3 = (-n1FE°1)+(-n2FE°2)

-n3FE°3= -F(n1E°1 + n2E°2)

n3E°3 = n1E°1 + n2E°2

2E°3 = 3×0.5 + 1×0.41

2E°3= 1.5 +0.41= 1.91

E°3= 1.91÷2

E°3= 0.95

Note: n= no of electrons