The heat of reaction does not depend upon

The combustion of carbon produces two oxides,$CO$ and $CO_2$,respectively. Their enthalpies of formation are $26 \ kcal$ and $94.3 \ kcal$ respectively. What is the enthalpy of combustion of carbon in $kcal$?

Which of the following reactions can be used to define the standard enthalpy of formation of $CO_{2_{(g)}}$?

$A$,$B$,$C$ and $D$ are some compounds. The enthalpy of formation of $A_{(g)}$,$B_{(g)}$,$C_{(g)}$ and $D_{(g)}$ is $9.7, -110, 81$ and $-393 \ kJ \ mol^{-1}$ respectively. What is $\Delta_r H$ (in $kJ \ mol^{-1}$) for the given reaction?
$A_{(g)} + 3B_{(g)} \longrightarrow C_{(g)} + 3D_{(g)}$

What is the heat of formation of $HCl_{(g)}$ from the following equation (in $kJ$)?
$H_{2(g)} + Cl_{2(g)} \rightarrow 2HCl_{(g)} \quad \Delta_{r}H = -194 \ kJ$

The reaction for the formation of $NaCl$ is: