Question

The change in standard Gibbs free energy for the reaction
${2SO}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons {2SO}_3$ is:
Given, $\Delta G_f^o{SO}_2=-300.2kJ{mol}^{-1}and\Delta G_f^o{SO}_3=371.0kJ$.

• A. $-241600J$
• B. $-131600J$
• C. $-141600J$
• D. $-241300J$

Answer 1

Answer: (C)

$-141600J$

Given, ${2SO}_2+O_2\rightleftharpoons {2SO}_3$

$△G^o=△G_f^o\left(Products\right)-△G_f^o\left(Reactants\right)$
$=2\left({\Delta }_f{G}_{{SO}_3}^o\right)-[2{\Delta }_f{G}_{{SO}_2}^o+{\Delta }_f{G}_{O_2}^o]$
$=2\times (-371)-[2\times (-300.2)+0]$
$=-141.6kJ=-141600J$