At 61 K , one mole of an ideal gas of 1.0 L volume expands isothermally and reversibly to a final volume of 10.0 L . What is the work done in the expansion?

The standard enthalpy of formation $\left(\Delta_f H^{\varphi}\right)$ of ammonia is $-46.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$, What is the $\Delta_{,} H^{\ominus}$ of the following reaction? $$ \mathrm{N}_2(g)+3 \mathrm{H}_2(g) \longrightarrow 2 \mathrm{NH}_3(g) $$

At $T(\mathrm{~K}) 2$ mole of an ideal gas is allowed to expand reversibly and isothermally from a pressure of 10 atmospheres to 1 atmosphere. The work done (in kJ ) is $\left(R=8.3 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}\right)$

For the reaction at $25^{\circ} \mathrm{C}, X_2 \mathrm{O}_4(l) \longrightarrow 2 \mathrm{XO}_2(g), \Delta U$ and $\Delta S$ are 2.1 k cal and $20 \mathrm{cal} / \mathrm{K}$ respectively. What is $\Delta \mathrm{G}$ for the reaction at the same temperature? ( $R=2 \mathrm{cal} \mathrm{K}^{-1} \mathrm{~mol}^{-1}$ )