Question

$2HCl\left(g\right)+F_2\left(g\right)⟶2HF\left(g\right)+{Cl}_2\left(g\right)$

Given, ${\Delta G}_{\int \left(HCl\right)g}^o=-273kJ{mol}^{-1}$;
${\Delta G}_{\int \left(HF\right)g}^o=-95.5kJ{mol}^{-1}$

The value of ${\Delta G}^o$ for the reaction at ${25}^{o}C$ (in $kJ$) is $x$ , then $x$ is ________.

Answer 1

$2HCl\left(g\right){+F}_2\left(g\right)⟶2HF\left(g\right)+{Cl}_2\left(g\right)$

The change in free energy that occurs when a compound is formed from its elements in their most thermodynamically stable states at standard-state conditions.

$\Delta G_{f\left(HCl\right)}^o=-273KJ{mol}^{-1}$

$\Delta G_{f\left(HF\right)}^o=-95.5KJ{mol}^{-1}$

$\Delta G^0=G_{products}-G_{reactants}$

We take $\Delta G_{f\left(C{l}_2\right)}^o$ and $\Delta G_{f\left(F_2\right)}^o$ to be zero as they are in standard state.

$\Delta G^o=2\times (-95.5)-2\times (-273)KJ=355KJ$