The heat of combustion of carbon monoxide at constant volume and at $17 \ ^oC$ is $-283.3 \ kJ$. Calculate its heat of combustion at constant pressure in $kJ$. $(R = 8.314 \ J \ K^{-1} \ mol^{-1})$ (in $.5$)

Given $H_{2(g)} + Cl_{2(g)} \rightarrow 2HCl_{(g)}$; $\Delta H = -44 \, Kcal$ and $2Na_{(s)} + 2HCl_{(g)} \rightarrow 2NaCl_{(s)} + H_{2(g)}$; $\Delta H = -152 \, Kcal$,calculate $\Delta H$ for the reaction $Na_{(s)} + 0.5 Cl_{2(g)} \rightarrow NaCl_{(s)}$ in $Kcal$.

Based on the values of $B.E.$ given,calculate the $\Delta_fH^o$ of $N_2H_4\, (g)$ in $kJ\, mol^{-1}$.
Given : $N-N = 159\, kJ\, mol^{-1};\, H-H = 436\, kJ\, mol^{-1}$
$N \equiv N = 941\, kJ\, mol^{-1};\, N-H = 398\, kJ\, mol^{-1}$

The enthalpy of reaction for the reaction: $2 H_{2(g)} + O_{2(g)} \to 2 H_{2}O_{(l)}$ is $\Delta_{r}H^{\theta} = -572 \ kJ \ mol^{-1}$. What will be the standard enthalpy of formation of $H_{2}O_{(l)}$?

Bond dissociation enthalpy of $H_2, Cl_2$ and $HCl$ are $434, 242$ and $431 \ kJ \ mol^{-1}$ respectively. Enthalpy of formation of $HCl$ is ............... $kJ \ mol^{-1}$

Explain Enthalpy of atomization $\left( \Delta_{a} H^{\theta} \right)$.