Work done in vaporisation of one mole of water at $373 \ K$ and the pressure of $1 \ atm$ is approximately (for ideal gas)......$J$

Which of the following is the correct expression of the first law of thermodynamics for adiabatic processes?

$A$ gas in a frictionless piston cylinder at a constant pressure of $1 \ atm$ expands from a volume of $2 \ L$ to $6 \ L$. In doing so,it absorbs $800 \ J$ of heat from the surroundings. The change in internal energy of the process is ..... $J$.

Two moles of an ideal monoatomic gas are allowed to expand adiabatically and reversibly from $300 \ K$ to $200 \ K$. The work done in the system is $... \ kJ$ $(C_V = 12.5 \ J/K/mol)$.

Five moles of an ideal gas at $293 \, K$ is expanded isothermally from an initial pressure of $2.1 \, MPa$ to $1.3 \, MPa$ against a constant external pressure of $4.3 \, MPa$. The heat transferred in this process is $...... \, kJ \, mol^{-1}$. (Rounded-off to the nearest integer) $\left[\right.$ Use $R = 8.314 \, J \, mol^{-1} \, K^{-1}\left.\right]$

$A$ mixture of gas expands from $0.03\, m^3$ to $0.06\, m^3$ at a constant pressure of $1\, MPa$ and absorbs $84\, kJ$ of heat during the process. The change in internal energy of the mixture is $.....\, kJ$.