If the bond formation energy of the $H-H$ bond is $-433 \ kJ \ mol^{-1}$,find the bond dissociation energy for $0.5 \ mol$ of $H_{2(g)}$. (in $kJ$)

Given:
$(i) \, C(\text{graphite}) + O_{2(g)} \to CO_{2(g)}; \Delta_r H^\ominus = x \, kJ \, mol^{-1}$
$(ii) \, C(\text{graphite}) + \frac{1}{2} O_{2(g)} \to CO_{(g)}; \Delta_r H^\ominus = y \, kJ \, mol^{-1}$
$(iii) \, CO_{(g)} + \frac{1}{2} O_{2(g)} \to CO_{2(g)}; \Delta_r H^\ominus = z \, kJ \, mol^{-1}$
Based on the above thermochemical equations,find out which one of the following algebraic relationships is correct?

The standard enthalpies of formation of $CO$ and $CO_2$ are $-110 \, kJ \, mol^{-1}$ and $-394 \, kJ \, mol^{-1}$ respectively. What will be the heat of combustion of $1 \, mol$ of graphite in $kJ$?

If the combustion of $1 \ g$ of graphite produces $20.7 \ kJ$ of heat,what will be the molar enthalpy change? Give the significance of the sign also.

According to Hess's Law,the enthalpy change of a reaction depends on which of the following?

For the reaction $H_{2} + I_{2} \rightarrow 2 HI$,provide the potential energy profile diagram and prove that it is an exothermic reaction.