When $\Delta H_{vap} = 30 \ kJ \ mol^{-1}$ and $\Delta S_{vap} = 75 \ J \ mol^{-1} \ K^{-1}$,then the temperature of vapour,at one atmosphere is . . . . $K$.

$A$ process is taking place at constant temperature and pressure. Then

Calculate the amount of work done during isothermal expansion of a gas from a volume of $4 \ dm^{3}$ to $6 \ dm^{3}$ against a constant external pressure of $3 \ atm$ (in $J$)?

Calculate the work done during the reversible isothermal expansion of $2 \ mol$ of an ideal gas at $298 \ K$ from $10 \ L$ to $20 \ L$ in $J$. (in $.9$)

The standard enthalpy and standard entropy of decomposition of $N_2O_4$ to $NO_2$ are $55.0 \ kJ \ mol^{-1}$ and $175.0 \ J \ K^{-1} \ mol^{-1}$ respectively. The standard free energy change for this reaction at $25 ^{\circ}C$ in $J \ mol^{-1}$ is $............$ $(Nearest \ integer)$.

For a reaction,$\Delta H = -40 \, kJ$ and $\Delta S = -50 \, J/K$. At what temperature range will it change from spontaneous to non-spontaneous?