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 $J$)?

Two moles of an ideal monoatomic gas are allowed to expand adiabatically and reversibly from $300 \ K$ to $200 \ K$. The work done in the system is $... \ kJ$ $(C_V = 12.5 \ J/K/mol)$.

If a gas expands adiabatically from $1 \, L$ to $12 \, L$ against a constant external pressure of $0.75 \, atm$,the $\Delta U$ of the gas is .... $J$. (in $.9$)

During an isothermal process,which of the following is true?

At constant $T$ and $P$,which one of the following statements is correct for the reaction,$CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)}$?

If $100 \ L$ of an ideal gas at a pressure of $2 \ atm$ is compressed isothermally and reversibly to a final volume of '$X$' $L$ and releases $460.6 \ L \ atm$ of heat,the final volume '$X$' (in $L$) is