What is the internal energy change when $2$ moles of an ideal gas at $25^{\circ} C$ is compressed isothermally and reversibly from $1.0 \ bar$ to $10.0 \ bar$?

For which of the following systems,the difference between $\Delta H$ and $\Delta U$ is not significant?
$(i)$ Solids
$(ii)$ Gases
$(iii)$ Mixture of gases and liquids
$(iv)$ Liquids

Explain free expansion.

The internal energy change when a system goes from state $A$ to $B$ is $40 \, kJ/mol$. If the system goes from $A$ to $B$ by a reversible path and returns to state $A$ by an irreversible path,what would be the net change in internal energy?

Work done by an ideal gas at a constant volume is

The amount of heat measured for a reaction in a bomb calorimeter is