Given the thermochemical equation,$2 H_{2(g)} + O_{2(g)} \rightarrow 2 H_2O_{(l)}$; $\Delta H = -571.6 \ kJ$. The heat of decomposition of water is:

Enthalpy of sublimation of a substance is equal to

Which of the following values of heat of formation indicates that the product is least stable in $kcal$?

The standard enthalpy of formation of $NH_3$ is $-46.0 \ kJ \ mol^{-1}.$ If the enthalpy of formation of $H_2$ from its atoms is $-436 \ kJ \ mol^{-1}$ and that of $N_2$ is $-712 \ kJ \ mol^{-1},$ the average bond enthalpy of $N-H$ bond in $NH_3$ is ................ $kJ \ mol^{-1}$

The heat of combustion of carbon is $-94 \ kcal$ at $1 \ atm$ pressure. The internal energy of $CO_2$ is .... $kcal$.

The enthalpy change at $298 \ K$ for the decomposition of water is given in the following two steps:
Step $I$: $H_2O_{(g)} \to H_{(g)} + OH_{(g)}$; $\Delta H = 498 \ kJ \ mol^{-1}$
Step $II$: $OH_{(g)} \to H_{(g)} + O_{(g)}$; $\Delta H = 428 \ kJ \ mol^{-1}$
The average bond enthalpy of the $O-H$ bond is $.... \ kJ \ mol^{-1}$