For which of the following reactions is $\Delta H \neq \Delta U$?

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. $(1 \ L \cdot bar = 101.32 \ J)$

If the initial internal energy of a system is $U_1$,and it absorbs $450 \ J$ of heat from the surroundings and performs $600 \ J$ of work,what will be the final internal energy of the system?

An ideal gas is subjected to a cyclic process involving four thermodynamic states. The amounts of heat $(Q)$ and work $(W)$ involved in each of these processes are:
$Q_1 = 6000 \, J, Q_2 = -5500 \, J, Q_3 = -3000 \, J, Q_4 = 3500 \, J$
$W_1 = 2500 \, J, W_2 = -1000 \, J, W_3 = -1200 \, J, W_4 = x \, J$
The ratio of the net work done by the gas to the total heat absorbed by the gas is $\eta$. The values of $|x|$ and $\eta$ respectively are:

One mole of an ideal gas at $27^oC$ is allowed to expand reversibly and adiabatically. If the work done by the system is $3 \, kJ$,then the final temperature of the gas will be ......$K$. (Given: $C_v = 20 \, J/K \cdot mol$)

For the $1^{st}$ law of thermodynamics,select the correct option.