The enthalpy of vaporization of water at $100 \, ^\circ C$ is $40.63 \, kJ \, mol^{-1}$. The value of $\Delta U$ for this process is ....... $kJ \, mol^{-1}$.

If $65 \ kJ$ of work is done on the system and it releases $25 \ kJ$ of heat,what is the change in internal energy of the system (in $kJ$)?

In a $1 \, L$ container,$2 \, mol$ of $CO$ and $1 \, mol$ of $O_2$ are taken. They react according to the equation: $2CO(g) + O_2(g) \rightarrow 2CO_2(g)$,$\Delta H = -560 \, kJ$. Given that $1 \, atm \cdot L = 0.1 \, kJ$,and the pressure changes from $70 \, atm$ to $40 \, atm$ at $500 \, K$,calculate the value of $\Delta U$ in $kJ$.

$A$ system is provided with $50 \ J$ of heat and the work done on the system is $10 \ J$. What is the change in internal energy of the system in joules?

$A$ mixture of $2 \ mol$ of carbon monoxide and $1 \ mol$ of oxygen in a closed vessel is ignited to convert the carbon monoxide to carbon dioxide. If $\Delta H$ is the enthalpy change and $\Delta E$ is the change in internal energy,then:

$4.0 \, L$ of an ideal gas is allowed to expand isothermally into vacuum until the total volume is $20 \, L$. The amount of heat absorbed in this expansion is $..... \, L \, atm$.