Latent heat of vaporisation of a liquid at $500 \ K$ and $1 \ atm$ pressure is $20.0 \ kcal/mol$. What will be the change in internal energy $(\Delta E)$ of $3 \ mol$ of liquid at same temperature in $kcal$?

The standard molar heat of formation of ethane,$CO_2$,and water $(l)$ are respectively $-21.1$,$-94.1$,and $-68.3 \ kcal$. The standard molar heat of combustion of ethane will be $kcal$.

The enthalpy of neutralisation of $KOH$ by a weak acid $(HA)$ is $-12.2 \ kcal \ mol^{-1}$. If the weak acid is $10 \%$ ionised,then the enthalpy of dissociation of $1 \ mole$ of $HA$ is. Given that the enthalpy of neutralisation of $KOH$ by $HCl$ is $-13.7 \ kcal \ mol^{-1}$.

The values of $\Delta H$ for the combustion of ethene and ethyne are $-341.1 \ kcal$ and $-310.0 \ kcal$ respectively. Which of the following is a better fuel?

$7 \ g$ of $N_{2(g)}$ at $27 \ ^oC$ is expanded reversibly and isothermally from an initial pressure of $0.5 \ MPa$ to a final pressure of $0.1 \ MPa$. Determine the approximate work done $[\ln \ 5 = 1.6]$ ..... $J$

For the reaction at $300 \, K$,$A_{(g)} + B_{(g)} \to C_{(g)}$,given $\Delta U = -3 \, kcal$ and $\Delta S = -10 \, cal/K$. The value of $\Delta G$ will be $...... \, cal$.