What is the enthalpy of vaporization of ethanol in $kJ/mol$? Given: boiling point $(b.p.)$ = $79.5 \, ^\circ C$ and entropy change $(\Delta S_{vap})$ = $109.8 \, J K^{-1} mol^{-1}$.

The heat of reaction for $C_2H_2 + H_2 \rightarrow C_2H_4$ is given by the following data:
$(i) \Delta H_f^o \text{ of } H_2O_{(\ell)} = -68.3 \ K \ cal \ mol^{-1}$
$(ii) \Delta H_{comb}^o \text{ of } C_2H_2 = -337.2 \ K \ cal \ mol^{-1}$
$(iii) \Delta H_{comb}^o \text{ of } C_2H_4 = -363.7 \ K \ cal \ mol^{-1}$

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 = $122 \ g/mol$)

For the reaction: $A_{(g)} + B_{(s)} \rightleftharpoons 2C_{(g)} + D_{(g)}$,given $\Delta U = 5.0 \ kcal$ and $\Delta S = 50 \ cal \ K^{-1}$ at $400 \ K$. Calculate $\Delta G$ for the reaction. (in $kcal$)

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 enthalpies of combustion of carbon and carbon monoxide are $-393.5 \, kJ \, mol^{-1}$ and $-283 \, kJ \, mol^{-1}$ respectively. The enthalpy of formation of carbon monoxide per mole is $....... \, kJ \, mol^{-1}$. (in $.5$)