10 g each of $\mathrm{NH}_3, \mathrm{~N}_2, \mathrm{Cl}_2$ and $\mathrm{H}_2 \mathrm{~S}$ are expanded isothermally and reversibly at same temperature. Identify gas that performs maximum work.

Identify the factor from following on which heat of reaction does not depend.

For the reaction,

$$2 \mathrm{H}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})} \longrightarrow 2 \mathrm{H}_2 \mathrm{O}_{(\mathrm{g})}, \Delta \mathrm{H}^{\circ}=-573.2 \mathrm{~kJ}$$

What is heat of decomposition of water per mol?

For the reaction,

$$\mathrm{C}_3 \mathrm{H}_{8(\mathrm{~g})}+5 \mathrm{O}_{2(\mathrm{~g})} \longrightarrow 3 \mathrm{CO}_{2(\mathrm{~g})}+4 \mathrm{H}_2 \mathrm{O}_{(\mathrm{l})}$$

at constant temperature, $\Delta \mathrm{H}-\Delta \mathrm{U}$ is