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

Which of the following is the correct expression of the first law of thermodynamics for an isothermal process?

$A$ gas absorbs $100 \ J$ of heat and is simultaneously compressed by a constant external pressure of $1.5 \ atm$ from a volume of $8.0 \ L$ to $2.0 \ L$. The change in internal energy for the gas in Joules is $(1 \ L \cdot atm = 101.32 \ J)$.

Calculate the final volume when $2$ moles of an ideal gas expand from $3 \ dm^3$ at constant external pressure $1.6 \ bar$ and the work done in the process is $800 \ J$. (in $dm^3$)

Consider the same expansion,but this time against a constant external pressure of $1 \ atm$.

The $\Delta U^{\theta}$ of combustion of methane is $-X \ kJ \ mol^{-1}.$ The value of $\Delta H^{\theta}$ is