The bond dissociation energy of molecules is.......

What is the value of $\Delta H^{\circ}$ for the formation of ethanol from ethene gas and liquid water from the following data (in $kJ$)?
$(i)$ $C_2H_5OH_{(l)} + 3O_{2_{(g)}} \longrightarrow 2CO_{2_{(g)}} + 3H_2O_{(l)}$ $\Delta H^{\circ} = -1368 \ kJ$
$(ii)$ $C_2H_{4_{(g)}} + 3O_{2_{(g)}} \longrightarrow 2CO_{2_{(g)}} + 2H_2O_{(l)}$ $\Delta H^{\circ} = -1410 \ kJ$

The bond dissociation enthalpy of $H_{2(g)}$ and $N_{2(g)}$ are $436 \ kJ \ mol^{-1}$ and $940 \ kJ \ mol^{-1}$ respectively,and the enthalpy of formation of $NH_{3(g)}$ is $-45 \ kJ \ mol^{-1}$. The enthalpy of atomisation of $NH_{3(g)}$ is ..... $kJ \ mol^{-1}$.

The heats of hydrogenation for $3-$-methylbutene and $2-$-pentene are $-30\, kcal/mol$ and $-28\, kcal/mol$ respectively. The heats of combustion of $2-$-methylbutane and pentane are $-784\, kcal/mol$ and $-782\, kcal/mol$ respectively. All the values are given under standard conditions. Taking into account that combustion of both alkanes gives the same products,what is $\Delta H$ (in $kcal/mol$) for the following reaction under same conditions?
$3-$-methylbutene $\rightleftharpoons$ $2-$-pentene

For a reaction $A + B + 30 \ kcal \longrightarrow \text{Product}$,the energy of activation of its backward reaction is $50 \ kcal$. The energy of activation of its forward reaction is :-

Which of the following equations corresponds to the definition of enthalpy of formation at $298 \ K$?