Question

Calculate the $\Delta G$ value from the following data and state whether the process will be spontaneous or non spontaneous at 298K. The heat of reaction is - 85.0 kJ and the entropy change for the reaction is +9.50 J/K.

Answer 1

As we know that,

$\Delta G=\Delta H-T\Delta S$

Given:-

$\Delta H=-85.0kJ$

$\Delta S=+9.50J/K=9.5\times {10}^{-3}kJ/K$

$T=298K$

$\therefore \Delta G=-85-(298\times 9.5\times {10}^{-3})$

$\Rightarrow \Delta G=-85-2.8=-87.8kJ$

As the value of $\Delta G$ is $-ve$, therefore the reaction is spontaneous.