The enthalpy of vaporisation of a liquid is $30 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and entropy of vaporisation is $75 \mathrm{JK}^{-1} \mathrm{~mol}^{-1}$. Calculate boiling point of liquid at 1 atm .

Find work done on 2 mole of an ideal gas at $27^{\circ} \mathrm{C}$ if it is compressed reversibly and isothermally from $5.05 \times 10^6 \mathrm{Nm}^{-2}$ to $1.01 \times 10^5 \mathrm{Nm}^{-2}$ pressure.

A system performs mechanical work equal to 15 kJ and looses 2 kJ of heat to surrounding. What is the change in internal energy of a system?

Find the constant external pressure required to expand a gas from 2.5 L to 4.5 L if amount of work done is 500 J at 298 K ?