What is molar enthalpy of vaporization?

What is an exothermic reaction and an endothermic reaction?

During the isothermal expansion of an ideal gas,its enthalpy change is ......

$1 \text{ mole}$ of an ideal gas is compressed isothermally and reversibly from an initial pressure $x \text{ kPa}$ to a final pressure $2x \text{ kPa}$ at $300 \text{ K}$. Find the work done $(R = 8.314 \text{ J K}^{-1} \text{mol}^{-1})$. (in $\text{ J}$)

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 $10.0 \ bar$?

An endothermic reaction is one in which