Heat of transition is the heat evolved or absorbed when a substance is converted from

The heat of combustion of a substance is:

Three thermochemical equations are given below:
$(i) C_{(graphite)} + O_{2(g)} \to CO_{2(g)}; \Delta_r H^\circ = x \ kJ \ mol^{-1}$
$(ii) C_{(graphite)} + \frac{1}{2} O_{2(g)} \to CO_{(g)}; \Delta_r H^\circ = y \ kJ \ mol^{-1}$
$(iii) CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)}; \Delta_r H^\circ = z \ kJ \ mol^{-1}$
Based on the above equations,find out which of the relationship given below is correct.

$AB$,$A_2$ and $B_2$ are diatomic molecules. If the bond enthalpies of $A_2$,$AB$ and $B_2$ are in the ratio $1:1:0.5$ and enthalpy of formation of $AB$ from $A_2$ and $B_2$ is $-100 \, kJ \, mol^{-1}$,what is the bond energy of $A_2$ in $kJ \, mol^{-1}$?

$H^{+}_{(aq)} + OH^{-}_{(aq)} \rightarrow H_2O_{(l)} + 56 \text{ kJ/mol}$. The heat of neutralization for the complete neutralization of $1 \text{ mole}$ of $H_2SO_4$ will be ...... $\text{kJ}$.

The value of $\Delta H_{O-H}$ is $109 \ kcal \ mol^{-1}$. Then,the formation of one mole of water in the gaseous state from $H_{(g)}$ and $O_{(g)}$ atoms is accompanied by: