Chemistry - Thermodynamics - II Question with Solution | TestHub

$∆H=∆U+∆ngRT$
$=2.1\times {10}^3+2\left(2\right)\left(300\right)$
$=2100+1200$
$=3300cal$
$∆G=∆H-T∆S$
$=3300-\left(300\right)\left(20\right)$
$=3300-6000$
$=-2700\mathrm{}\mathrm{c}\mathrm{a}\mathrm{l}\mathrm{s}=-2.7\mathrm{}\mathrm{k}\mathrm{c}\mathrm{a}\mathrm{l}$

Gibbs free energy can be visualized as the amount of useful energy present in a thermodynamic system that can be utilized to perform some useful work.