For the combustion of $1 \ mol$ of liquid benzene at $298 \ K$,the heat of reaction at constant pressure is $-3268 \ kJ \ mol^{-1}$. What is the heat of combustion at constant volume? $(R = 8.314 \times 10^{-3} \ kJ \ K^{-1} \ mol^{-1})$

The value of $\Delta H_{transition}$ for $C(\text{graphite}) \rightarrow C(\text{diamond})$ is $1.9 \ kJ/mol$ at $25^{\circ}C$. The entropy of graphite is higher than the entropy of diamond. This implies that which of the following is incorrect $:-$

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?

An electric heater of power $600 \, W$ takes $8 \, \text{minutes}$ to evaporate $80 \, mL$ of water. The enthalpy of vaporization of water is ......... $kJ \, mol^{-1}$.

One mole of an ideal gas at $900 \ K$ undergoes two reversible processes,$I$ followed by $II$,as shown in the graph. If the work done by the gas in the two processes is the same,the value of $\ln \frac{V_3}{V_2}$ is. . . . . . . . ($U$: internal energy,$S$: entropy,$p$: pressure,$V$: volume,$R$: gas constant). (Given: molar heat capacity at constant volume,$C_{V, m}$ of the gas is $\frac{5}{2} R$)

The reversible expansion of an ideal gas under adiabatic and isothermal conditions is shown in the figure. Which of the following statement$(s)$ is (are) correct?
$(A)$ $T_1 = T_2$
$(B)$ $T_3 > T_1$
$(C)$ $W_{\text{isothermal}} > W_{\text{adiabatic}}$
$(D)$ $\Delta U_{\text{isothermal}} > \Delta U_{\text{adiabatic}}$