What is the work done during the oxidation of $4 \ mol$ of $SO_{2(g)}$ to $SO_{3(g)}$ at $27^{\circ} C$ (in $kJ$)? $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$

An ideal gas,$\overline{C}_{V} = \frac{5}{2} R$,is expanded adiabatically against a constant pressure of $1 \ atm$ until it doubles in volume. If the initial temperature and pressure are $298 \ K$ and $5 \ atm$,respectively,then the final temperature is . . . . . . $K$ (nearest integer). [$\overline{C}_{V}$ is the molar heat capacity at constant volume]

For water at $100^{\circ} C$ and $1 \, bar$,$\Delta_{vap} H - \Delta_{vap} U = ...... \times 10^{2} \, J \, mol^{-1}$. (Round off to the Nearest Integer) $[Use : R = 8.31 \, J \, mol^{-1} \, K^{-1}]$ [Assume volume of $H_{2}O_{(\ell)}$ is much smaller than volume of $H_{2}O_{(g)}$. Assume $H_{2}O_{(g)}$ treated as an ideal gas]

Consider the same expansion,but this time against a constant external pressure of $1 \ atm$.

Calculate the change in enthalpy in a chemical reaction when work done is $-800 \ J$ and increase in internal energy is $600 \ J$. (in $J$)

If the internal energy of an ideal gas decreases by the same amount of the work done by the system,the process is