Energy required to dissociate $4 \ g$ of gaseous hydrogen into free gaseous atoms is $208 \ kcal$ at $25 \ ^oC$. The bond energy of $H-H$ bond will be

The standard enthalpy of combustion of $C$ (graphite), $H_{2(g)}$ and $CH_3OH_{(l)}$ respectively are $-393 \ kJ \ mol^{-1}$, $-286 \ kJ \ mol^{-1}$ and $-726 \ kJ \ mol^{-1}$. What is the standard enthalpy of formation of methanol?

What is the enthalpy change for the reaction $2C(\text{graphite}) + 3H_{2(g)} \rightarrow C_2H_{6(g)}$ called?

Which of the following reactions satisfies the following conditions?
$(a)$ Heat of combustion reaction
$(b)$ Heat of formation reaction
$(c)$ An exothermic reaction
$(d)$ Not a neutralization reaction

The standard enthalpy of formation of $CO_{(g)}$, $CO_{2(g)}$, $N_2O_{(g)}$ and $N_2O_{4(g)}$ are respectively $-110$, $-393$, $81$ and $-10 \ kJ \ mol^{-1}$. The enthalpy change (in $kJ$) of the following reaction is $N_2O_{4(g)} + 3CO_{(g)} \longrightarrow N_2O_{(g)} + 3CO_{2(g)}$

Based on the following thermochemical reactions:
$H_2O_{(g)} + C_{(s)} \rightarrow CO_{(g)} + H_{2(g)} ; \Delta H = 131 \ kJ$
$CO_{(g)} + \frac{1}{2} O_{2(g)} \rightarrow CO_{2(g)} ; \Delta H = -282 \ kJ$
$H_{2(g)} + \frac{1}{2} O_{2(g)} \rightarrow H_2O_{(g)} ; \Delta H = -242 \ kJ$
$C_{(s)} + O_{2(g)} \rightarrow CO_{2(g)} ; \Delta H = x \ kJ$
The value of $x$ will be: