Calculate the change in internal energy of the system if $25 \ kJ$ of work is done by the system and it absorbs $10 \ kJ$ of heat. (in $kJ$)

If $3 \ mol$ of an ideal gas at $300 \ K$ expand isothermally from $30 \ dm^3$ to $45 \ dm^3$ against a constant opposing pressure of $80 \ kPa$,then the amount of heat transferred is . . . . . . $J$.

$A$ gas absorbs $120 \text{ J}$ of heat and expands by $300 \times 10^{-6} \text{ m}^3$ against a constant external pressure of $2 \times 10^5 \text{ Nm}^{-2}$. What will be the change in internal energy of the system (in $\text{ J}$)?

For the reaction $FeCO_{3(s)} \to FeO_{(s)} + CO_{2(g)}$,$\Delta H = 82.8 \ kJ$ at $25 \ ^oC$. What is $\Delta U$ at $25 \ ^oC$ in $kJ$?

Which of the following processes exhibits a decrease in the internal energy of a system?

When a system absorbs $8 \ kJ$ of heat and does $2.2 \ kJ$ of work on the surroundings,calculate the internal energy change. (in $kJ$)