Given that bond energies of $H-H$ and $Cl-Cl$ are $430 \ kJ \ mol^{-1}$ and $240 \ kJ \ mol^{-1}$ respectively and $\Delta H_f$ for $HCl$ is $-90 \ kJ \ mol^{-1},$ the bond enthalpy of $HCl$ is ............... $kJ \ mol^{-1}$.

Given that the bond energy of $H-H$ bonds is $436 \ kJ/mol$,$O-H$ bonds is $464 \ kJ/mol$,and $O=O$ bonds is $496 \ kJ/mol$,what is the approximate heat of reaction for $2H_2 + O_2 \longrightarrow 2H_2O$ in $kJ/mol$?

Given that:
$C_{(s)} + O_{2(g)} \to CO_{2(g)}, \Delta H = -394 \ kJ$
$2H_{2(g)} + O_{2(g)} \to 2H_2O_{(l)}, \Delta H = -568 \ kJ$
$CH_{4(g)} + 2O_{2(g)} \to CO_{2(g)} + 2H_2O_{(l)}, \Delta H = -892 \ kJ$
Calculate the heat of formation of $CH_{4(g)}$ in $kJ$.

Given,
$NO_{(g)} + O_{3(g)} \longrightarrow NO_{2(g)} + O_{2(g)}; \Delta H = -198.9 \, kJ/mol$
$O_{3(g)} \longrightarrow 3/2 O_{2(g)}; \Delta H = -142.3 \, kJ/mol$
$O_{2(g)} \longrightarrow 2O_{(g)}; \Delta H = +495.0 \, kJ/mol$
The enthalpy change $(\Delta H)$ for the following reaction is $..... \, kJ/mol$
$NO_{(g)} + O_{(g)} \longrightarrow NO_{2(g)}$

The bond energies of $H-H$ and $Cl-Cl$ are $430 \ kJ \ mol^{-1}$ and $240 \ kJ \ mol^{-1}$ respectively. If the $\Delta H_f$ (enthalpy of formation) of $HCl$ is $-90 \ kJ \ mol^{-1}$,what is the $H-Cl$ bond energy in $kJ \ mol^{-1}$?

For the reactions $(i) \, H_{2(g)} + Cl_{2(g)} \to 2HCl_{(g)} + x \, kJ$ and $(ii) \, H_{2(g)} + Cl_{2(g)} \to 2HCl_{(\ell)} + y \, kJ$,which of the following statements is correct?