Question

For the following reaction: $K_p=1.7\times {10}^7$ at ${25}^{o}C$
${Ag}^{+}(aq.)+2{NH}_3\left(g\right)\rightleftharpoons {\left[Ag{\left({NH}_3\right)}_2\right]}^{+}$
what value of $\Delta G^o$ in $kJ$?

• A. $-41.2$
• B. $-17.9$
• C. $+17.9$
• D. $+41.2$

Answer 1

The correct option is A $-41.2$

For the following reaction: $K_p=1.7\times {10}^7$ at ${25}^{o}C$\
${Ag}^{+}(aq.)+2{NH}_3\left(g\right)\rightleftharpoons {\left[Ag{\left({NH}_3\right)}_2\right]}^{+}$
The value of $\Delta G^o$ is $-41.2$ $kJ$.
$\Delta G^o=-2.303RT\log K_p$
$\Delta G^o=-2.303\times 8.314J/mol/K\times (25+273)K\times \log 1.7\times {10}^7$
$\Delta G^o=-41256J{mol}^{-1}$
$\Delta G^o=-41256J{mol}^{-1}\times \frac{1kJ}{1000J}$
$\Delta G^o=-41.2kJ{mol}^{-1}$