The free energy for a reaction having $\Delta H = 31400 \, cal$ and $\Delta S = 32 \, cal \, K^{-1} \, mol^{-1}$ at $1000 \, ^oC$ is ....... $cal$.

For a reaction to be spontaneous at all temperatures, the values of enthalpy change $\Delta H$ and entropy change $\Delta S$ should be:

The value of ${\left[ {\frac{dG}{dT}} \right]_P}$ is ....

Values of $\Delta H$ and $\Delta S$ for five different reactions are given below. On the basis of these values,predict which one of these will be spontaneous at all temperatures.

Reaction	$\Delta H \ (kJ \ mol^{-1}) / \Delta S \ (J \ K^{-1} \ mol^{-1})$
$I$	$+98.0, +14.8$
$II$	$-55.5, -84.6$
$III$	$+28.3, -17.0$
$IV$	$-40.5, +24.6$
$V$	$+34.7, 0.0$

Calculate the work done during the reversible isothermal expansion of $2 \ mol$ of an ideal gas at $298 \ K$ from $10 \ L$ to $20 \ L$ in $J$. (in $.9$)

$\Delta H$ and $\Delta S$ for a reaction are $+30.0 \ kJ \ mol^{-1}$ and $0.06 \ kJ \ K^{-1} \ mol^{-1}$ at $1 \ atm$ pressure. The temperature at which free energy change is equal to zero and the nature of the reaction below this temperature are: