Which of the following is the correct expression of the first law of thermodynamics for an isothermal process?

Which of the following relations is correct for the internal energy change $(\Delta U)$ in a process occurring at constant volume?

Calculate the internal energy change of one mole of an ideal gas during an adiabatic free expansion process from a volume of $2 \ L$ to $5 \ L$.

$1 \, \text{mole}$ of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27^{\circ}C$. The work done is $3 \, \text{kJ} \, \text{mol}^{-1}$. The final temperature of the gas is $...... \text{K}$ (Nearest integer). Given $C_{V} = 20 \, \text{J} \, \text{mol}^{-1} \, \text{K}^{-1}$.

At the $1$ bar pressure,the volume of a gas is $0.6 \ L$. If the gas receives $122 \ J$ of heat at $1$ bar pressure,the volume becomes $2 \ L$. Calculate the change in its internal energy. $(1 \ L \cdot bar = 101.32 \ J)$

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 $R = 8.314 \, J \, mol^{-1} \, K^{-1}\left.\right]$