The free energy change for the following reactions are given below:
$C_2H_{2(g)} + \frac{5}{2}O_{2(g)} \to 2CO_{2(g)} + H_2O_{(l)}; \Delta G^o = -1234 \ kJ$
$C_{(s)} + O_{2(g)} \to CO_{2(g)}; \Delta G^o = -394 \ kJ$
$H_{2(g)} + \frac{1}{2}O_{2(g)} \to H_2O_{(l)}; \Delta G^o = -237 \ kJ$
What is the standard free energy change for the reaction $H_{2(g)} + 2C_{(s)} \to C_2H_{2(g)}$ in $kJ$?

An isolated box,equally partitioned,contains two ideal gases $A$ and $B$ as shown in the figure. When the partition is removed,the gases mix. The changes in enthalpy $(\Delta H)$ and entropy $(\Delta S)$ in the process,respectively,are

The heat liberated when $1.89 \ g$ of benzoic acid is burnt in a bomb calorimeter at $25 \ ^\circ C$ increases the temperature of $18.94 \ kg$ of water by $0.632 \ ^\circ C$. If the specific heat of water at $25 \ ^\circ C$ is $0.998 \ cal/g \cdot ^\circ C$,the value of the heat of combustion of benzoic acid is .... $kcal/mol$. (Molar mass of benzoic acid = $122 \ g/mol$)

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?
$(A)$ $T_1 = T_2$
$(B)$ $T_3 > T_1$
$(C)$ $W_{\text{isothermal}} > W_{\text{adiabatic}}$
$(D)$ $\Delta U_{\text{isothermal}} > \Delta U_{\text{adiabatic}}$

Identify the correct statement from the following regarding a chemical reaction.

An organic compound $C_xH_yO_z$ on complete combustion provides equivolume of products $CO_{2(g)}$ and $H_2O_{(g)}$,which is individually double the volume of the organic compound taken. In the process,the volume of oxygen consumed is the same as the volume of $CO_2$ produced,and the liberated heat during combustion is $500 \ kcal/mol$ at constant pressure and $500 \ K$. The formula of the organic compound and $\Delta U$ for the reaction will be: