Which of the following $p-V$ curves represents the maximum work done?

For an isothermal expansion of $2 \, \text{mol}$ of a gas at $298 \, K$ from $5 \, dm^3$ to $40 \, dm^3$ under constant external pressure,the work done $(W)$ and the reversible work $(W_{rev})$ are,respectively:

For the reaction $CO_{(g)} + \frac{1}{2}O_{2_{(g)}} \rightarrow CO_{2_{(g)}}$ at $17^o C$ and constant volume,the heat of reaction is $-67.71 \, K \, cal$. What is the heat of reaction at constant pressure at $17^o C$ in $K \, cal$?

Match the transformations in Column-$I$ with the appropriate options in Column-$II$.

Column-$I$	Column-$II$
$(A) \; CO_{2(s)} \to CO_{2(g)}$	$(p) \; \text{Transition state}$
$(B) \; CaCO_{3(s)} \to CaO_{(s)} + CO_{2(g)}$	$(q) \; \text{Allotropic change}$
$(C) \; 2H^{\cdot} \to H_{2(g)}$	$(r) \; \Delta H > 0$
$(D) \; P_{\text{(white solid)}} \to P_{\text{(red solid)}}$	$(s) \; \Delta S > 0$
	$(t) \; \Delta S < 0$

One mole of Argon is heated using $PV^{5/2} = \text{constant}$. By what amount is heat absorbed during the process,when the temperature changes by $\Delta T = 26 \ K$ (in $J$)? (Take $R = 8.314 \ J \ mol^{-1} K^{-1}$)

Identify the correct statements from the following.
$I$. At $0 \ K$,the entropy of pure crystalline materials approaches zero.
$II$. Entropy for the process,$H_2O_{(l)} \longrightarrow H_2O_{(g)}$ decreases.
$III$. Gibbs' energy is a state function.