What is the enthalpy change (in $J$) for converting $9 \ g$ of $H_2O(l)$ at $+10^{\circ}C$ to $H_2O(l)$ at $+20^{\circ}C$? $(C_p(H_2O(l)) = 75 \ J \ mol^{-1} \ K^{-1})$

What is the work done when $2 \text{ mole}$ of an ideal gas are expanded isothermally and reversibly from $5 \text{ m}^{3}$ to $10 \text{ m}^{3}$ at $300 \text{ K}$ (in $\text{ kJ}$)? $(R=8.314 \text{ J K}^{-1} \text{ mol}^{-1})$

$A$ system goes from $A$ to $B$ via two processes $I$ and $II$ as shown in the figure. If $\Delta U_1$ and $\Delta U_2$ are the changes in internal energies in the processes $I$ and $II$ respectively,then:

Explain the measurement of $\Delta U$ and $\Delta H$ by calorimetry.

$A$ $5 \, L$ cylinder contains $10 \, mol$ of $O_2$ gas at $27 \, ^\circ C$. Due to a leak,the gas escapes into the atmosphere until the pressure inside the cylinder equals the atmospheric pressure $(1.0 \, atm)$. What is the work done by the gas?

Five moles of an ideal gas at $1 \ bar$ and $298 \ K$ is expanded into vacuum to double the volume. The work done is :-