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 $kJ$)

Calculate the bond enthalpy of the $H-Cl$ bond from the following reaction:
$H_{2(g)} + Cl_{2(g)} \rightarrow 2 HCl_{(g)}$,$\Delta_{r} H^{\circ} = -185 \ kJ \ mol^{-1}$
(Given bond enthalpies of $H-H$ and $Cl-Cl$ bonds are $435.0 \ kJ \ mol^{-1}$ and $244 \ kJ \ mol^{-1}$ respectively.)

Which of the following equations has $\Delta_{f} H^{\circ}$ and $\Delta H^{\circ}$ the same?

In the reaction $S + \frac{3}{2} O_{2} \rightarrow SO_{3} + 2x \ kJ$ and $SO_{2} + \frac{1}{2} O_{2} \rightarrow SO_{3} + y \ kJ$,the heat of formation of $SO_{2}$ is

The bond dissociation energies of gaseous $H_2$,$Cl_2$ and $HCl$ are $104$,$58$ and $103 \ kcal$ respectively. The enthalpy of formation of $HCl$ gas would be $... \ kcal$.

When $50 \ cm^3$ of a strong acid is added to $50 \ cm^3$ of an alkali,the temperature rises by $5 \ ^oC$. If $250 \ cm^3$ of each liquid are mixed,the temperature rise would be $... \ ^oC$.