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

If $\Delta G$ and $\Delta S$ for the reaction $A_{(g)} \rightarrow B_{(g)} + 2C_{(g)}$ at $2000 \ K$ are $-40 \ kJ \ mol^{-1}$ and $0.22 \ kJ \ K^{-1} \ mol^{-1}$ respectively,the change in internal energy for the same reaction approximately (in $kJ \ mol^{-1}$) is

The standard entropies of $X_2, Y_2$ and $XY_3$ are $60, 40$ and $50 \ J \ K^{-1} \ mol^{-1}$ respectively. For the reaction $X_2 + 3Y_2 \rightleftharpoons 2XY_3; \Delta H = -60 \ kJ$ to be at equilibrium,the temperature should be.....$K$

$5$ moles of an ideal gas is expanded from $(10 \ L, 300 \ K)$ to $(20 \ L, 300 \ K)$ against a constant external pressure of $1.0 \ bar$. The only incorrect value of physical quantities for this change in state of the system,is-

Total enthalpy change for freezing of $1 \ mol$ of water at $10^{\circ} C$ to ice at $-10^{\circ} C$ is $..........$ (Given : $\Delta_{fus} H = x \ kJ / mol$,$C_{p}[H_2O_{(l)}] = y \ J \ mol^{-1} \ K^{-1}$,$C_{p}[H_2O_{(s)}] = z \ J \ mol^{-1} \ K^{-1}$)

An ideal gas in a thermally insulated vessel at internal pressure $= P_1$,volume $= V_1$ and absolute temperature $= T_1$ expands irreversibly against zero external pressure,as shown in the diagram. The final internal pressure,volume and absolute temperature of the gas are $P_2, V_2$ and $T_2$,respectively. For this expansion,
$(A) \ q = 0$
$(B) \ T_2 = T_1$
$(C) \ P_2 V_2 = P_1 V_1$
$(D) \ P_2 V_2^\gamma = P_1 V_1^\gamma$