For the reaction $CaCO_{3(s)} \rightarrow CaO_{(s)} + CO_{2(g)}$ at $977 \, ^\circ C$,$\Delta H = 174 \, kJ/mol$. Calculate $\Delta U$ in $kJ$.

Identify the reaction for which $\Delta H \neq \Delta E$ :

For the reaction $N_2(g) + 3H_2(g) \rightarrow 2NH_3(g)$ at constant temperature and pressure,if $\Delta H$ and $\Delta U$ are the enthalpy and internal energy changes for the reaction,which of the following equations is correct?

The volume of a gas at $STP$ is $1.5 \ L$. When $300 \ J$ of heat is supplied to it at $1 \ atm$ pressure,its volume becomes $2 \ L$. What is the value of $\Delta U$ in $J$ for this process? $(1 \ L \cdot atm = 101 \ J)$

$A$ gaseous sample expands from $200 \, cm^3$ to $500 \, cm^3$ against a constant external pressure of $750 \, torr$ while absorbing $1.5 \, J$ of heat. What is the change in internal energy of the system in $J$? $(1 \, atm \cdot L = 101.3 \, J)$

Calculate $\Delta H$ for the following reaction at $25^{\circ} C$.
$NH_2CN_{(g)} + \frac{3}{2} O_{2_{(g)}} \longrightarrow N_{2_{(g)}} + CO_{2_{(g)}} + H_2O_{(l)}$
$(\Delta U = -740.5 \ kJ, R = 8.314 \ J \ K^{-1} \ mol^{-1})$