Question

The standard e.m.f. of a cell, involving one electron change is found to be 0.591 V at ${25}^0$C. The equilibrium constant of the reaction is (F = 96500Cmol${}^{-1}$, R = 8.314JK${}^{-1}$ mol${}^{-1}$) :

• A. $1.0\times {10}^1$
• B. $1.0\times {10}^5$
• C. $1.0\times {10}^{10}$
• D. $1.0\times {10}^{30}$

Answer 1

The correct option is C $1.0\times {10}^{10}$

The standard emf of cell $E_{cell}^0=0.591V$.

The expression for the equilibrium constant is $E_{cell}^0=\frac{0.0591}{n}logK.$

Substitute values in the above expression.

$0.591V=\frac{0.0591}{1}logK$

$logK=10$

$K=1\times {10}^{10}.$

Option C is correct.