$A$ certain system is exothermic by $260 \ kJ$ and does $10 \ kJ$ of work. What is the change in internal energy (in $kJ$)?

When a certain volume of gas expands against a constant external pressure of $2.40 \times 10^5 \ Pa$ at $300 \ K$ to a final volume of $2.2 \times 10^{-3} \ m^3$. If the work obtained is $-0.048 \ kJ$,what is the initial volume of the gas?

If $2 \ kJ$ of heat is released from the system and $6 \ kJ$ of work is done on the system,what is the internal energy change $(\Delta U)$ of the system?

$A$ system receives $224 \ J$ of heat and does $156 \ J$ of work. Calculate the change in internal energy. (in $J$)

Observe the following reaction: $ABO_{3(s)} \xrightarrow{1000 \ K} AO_{(s)} + BO_{2(g)}$. $\Delta_{r} H$ for this reaction is $x \ kJ \ mol^{-1}$. What is its $\Delta_{r} U$ (in $kJ \ mol^{-1}$) at the same temperature? $(R = 8.3 \ J \ mol^{-1} \ K^{-1})$

$A$ sample of gas absorbs $4000 \ kJ$ of heat and the surrounding does $2000 \ J$ of work on the sample. What is the value of $\Delta U$ (in $kJ$)?