What is the change in internal energy when a system releases $8 \ kJ$ of heat and performs $660 \ J$ of work on the surroundings (in $J$)?

$4.0 \, L$ of an ideal gas is allowed to expand isothermally into vacuum until the total volume is $20 \, L$. The amount of heat absorbed in this expansion is $..... \, L \, atm$.

Which of the following statements regarding the first law of thermodynamics is correct?

One mole of an ideal gas is allowed to expand reversibly and adiabatically from a temperature of $27\,^{\circ}C$. If the work done during the process is $3\, kJ$,then the final temperature of the gas is $...\, K$.

The volume of a gas at $STP$ is $1.5 \ L$. When $300 \ J$ of heat is supplied to it at $1 \ atm$ pressure,its volume becomes $2 \ L$. What is the value of $\Delta U$ in $J$ for this process? $(1 \ L \cdot atm = 101 \ J)$

If $2 \text{ mole}$ of an ideal gas expand isothermally and reversibly at $27^{\circ}C$ from $1 \text{ dm}^3$ to $1 \text{ m}^3$, calculate the work done. [$R = 8.314 \text{ J K}^{-1} \text{mol}^{-1}$] (in $\text{ kJ}$)