In isolated system, find the condition for spontaneous reaction.
In isolated system, find the condition for spontaneous reaction.
$\Delta U=0, \Delta S=0, \Delta G=0$
$\Delta U < 0, \Delta S>0, \Delta G < 0$
$\Delta U=0, \Delta S>0, \Delta G < 0$
$\Delta U < 0, \Delta S < 0, \Delta G < 0$
Solution
For an isolated system, $q=0, w=0$
$\begin{aligned} & \therefore \quad \Delta U=0 \\ & \Delta G=\Delta H-T \Delta S\end{aligned}$
For spontaneous reaction, $\Delta G=-v$ e. $\Delta H=0$ for an isolated system.
Thus, $\Delta S>0$ for the reaction to be spontaneous.