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

$A$ system does $394 \ J$ of work on the surroundings by absorbing $701 \ J$ of heat. What is the change in internal energy of the system (in $J$)?

Identify from the following reactions the one that exhibits negative work done by the system.

$C_2H_5OH(l) + 3O_2(g) \rightarrow 2CO_2(g) + 3H_2O(l)$. The enthalpy change $(\Delta H)$ for the above reaction at $27^{\circ}C$ is $-1366.5 \text{ kJ mol}^{-1}$. Calculate the internal energy change $(\Delta U)$ for the same reaction at this temperature.

$A$ system is provided $50 \text{ J}$ of heat and work done on the system is $10 \text{ J}$. What is the change in internal energy (in $\text{ J}$)?

For the reaction $N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)}$,the relationship between $\Delta H$ and $\Delta U$ is: