For the reaction $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$ at $298 \ K$,the enthalpy change $(\Delta H)$ is $-92.38 \ kJ$. What will be the internal energy change $(\Delta U)$ at $298 \ K$ in $kJ$?

Calculate the quantity of heat released from a system when $2 \text{ moles}$ of an ideal gas are compressed isothermally from a volume of $25 \text{ dm}^3$ to $10 \text{ dm}^3$ at a constant external pressure of $4 \text{ bar}$. (in $\text{ kJ}$)

For an isochoric process,the first law of thermodynamics can be expressed as:

$A$ gas absorbs $150 \ J$ of heat and expands by $300 \ cm^3$ against a constant external pressure of $2 \times 10^5 \ N \ m^{-2}$. What is the change in internal energy $(\Delta U)$ of the system (in $J$)?

In a closed insulated container,a liquid is stirred with a paddle to increase its temperature. Which of the following is correct?

$A$ system receives $100 \ cal$ of heat,and at the same time,$50 \ cal$ of work is done by the system. Calculate the change in internal energy. (in $cal$)