The $\Delta H$ for vaporisation of a liquid is $20 \, kJ/mol$. Assuming ideal behaviour,the change in internal energy for the vaporisation of $1 \, mole$ of the liquid at $60^{\circ} C$ and $1 \, bar$ is close to $.... \, kJ/mol$

For the hypothetical reaction
$A_{2(g)} + B_{2(g)} \rightleftharpoons 2AB_{(g)}$
$\Delta_r G^o$ and $\Delta_r S^o$ are $20 \ kJ/mol$ and $-20 \ J K^{-1} mol^{-1}$ respectively at $200 \ K$.
If $\Delta_r C_P$ is $20 \ J K^{-1} mol^{-1}$ then $\Delta_r H^o$ at $400 \ K$ is.....$kJ/mol$

$1 \ mol$ of $NH_3$ $(\gamma = 4/3)$ gas at $27 \ ^\circ C$ is expanded under reversible adiabatic conditions to make the volume $8$ times. Calculate the work done in $cal$.

The heats of combustion of $CH_4, C_2H_6, C_2H_4$,and $C_2H_2$ at the same temperature are $-212.8, -373.0, -337.0$,and $-310.5 \, Kcal$ respectively. Which of these gases is the best fuel?

$36 \, mL$ of pure water takes $100 \, sec$ to evaporate from a vessel and heater connected to an electric source which delivers $806 \, watt$. The $\Delta H_{\text{vaporization}}$ of $H_2O$ is $... \, kJ/mol$

The combustion of one mole of benzene takes place at $298 \, K$ and $1 \, atm$. After combustion,$CO_{2(g)}$ and $H_2O_{(l)}$ are produced and $3267.0 \, kJ$ of heat is liberated. Calculate the standard enthalpy of formation,$\Delta_f H^{\ominus}$ of benzene. Standard enthalpies of formation of $CO_{2(g)}$ and $H_2O_{(l)}$ are $-393.5 \, kJ \, mol^{-1}$ and $-285.83 \, kJ \, mol^{-1}$ respectively.