Question

The standard Gibbs free energy change $(\Delta G^o$) at ${25}^{o}C$ for the dissociation of $N_2{O}_4\left(g\right)$ to ${NO}_2\left(g\right)$ is (given, equilibrium constant $=0.15,R=8.314JK/mol$):

• A. $1.1kJ$
• B. $4.7kJ$
• C. $8.1kJ$
• D. $38.2kJ$

Answer 1

The correct option is B $4.7kJ$

$\Delta G^o=-2.303RT\log K$

$=-2.303\times 8.314\times 298\times \log 0.15$

$=-2.303\times 8.314\times 298\times (-0.8239)$

$=4700.25J=4.7kJ$