Identify the correct statements from the following:
$I$. $\Delta_{r} G$ is zero for $A \rightleftharpoons B$ reaction.
$II$. The entropy of pure crystalline solids approaches zero as the temperature approaches absolute zero.
$III$. $\Delta U$ of a reaction can be determined using a bomb calorimeter.

For isothermal expansion of an ideal gas, the correct combination of the thermodynamic parameters will be

$10 \ g$ each of $NH_3, N_2, Cl_2$ and $H_2S$ are expanded isothermally and reversibly at the same temperature. Identify the gas that performs maximum work.

The entropy change associated with the conversion of $1 \ kg$ of ice at $273 \ K$ to water vapours at $383 \ K$ is: (Specific heat of water liquid and water vapours are $4.2 \ kJ \ K^{-1} \ kg^{-1}$ and $2.0 \ kJ \ K^{-1} \ kg^{-1},$ heat of fusion and vaporisation of water are $334 \ kJ \ kg^{-1}$ and $2491 \ kJ \ kg^{-1},$ respectively) $(\ln \ 273 = 5.61, \ln \ 373 = 5.92, \ln \ 383 = 5.95)$

Consider the following reaction :
$2A (g) + B (g) \rightarrow 2D(g)$
$\Delta U^{\circ} = -10 \text{ kJ mol}^{-1}$ and $\Delta S^{\circ} = -44 \text{ J K}^{-1} \text{ mol}^{-1}$ at $298 \text{ K}$.
Identify the correct option with $\Delta G^{\circ}$ for the reaction and spontaneity of the reaction at $298 \text{ K}$.
(Given : $R = 8.31 \text{ J mol}^{-1} \text{ K}^{-1}$)

The heats of combustion $\Delta H$ of $CH_4$,$C_2H_6$,$C_2H_4$,and $C_2H_2$ gases are $-212.8$,$-373.0$,$-337.0$,and $-310.5 \ kcal$ respectively at the same temperature. Which of these gases is the best fuel?