$A$ gas absorbs $150 \ J$ of heat and expands by $300 \ cm^3$ against a constant external pressure of $2 \times 10^5 \ N \ m^{-2}$. What is the change in internal energy $(\Delta U)$ of the system (in $J$)?

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 $.9$)

Calculate the change in internal energy of the system if $20 \ kJ$ of work is done on the system and it releases $10 \ kJ$ of heat in a particular reaction. (in $kJ$)

For the reaction $PCl_{5(g)} \to PCl_{3(g)} + Cl_{2(g)}$,which of the following relations is correct?

For which reaction is $\Delta H \neq \Delta U$?

$A$ gas expands against a variable pressure given by $P = \frac{20}{V}$ ($P$ in $atm$ and $V$ in $L$). During expansion from volume of $1 \ L$ to $10 \ L$,the gas undergoes an increase in internal energy of $400 \ J$. How much heat is absorbed by gas during expansion (in $J$)? (Given: $1 \ L \cdot atm = 101.3 \ J$)