The enthalpy change for the reaction $C(s) + O_2(g) \to CO_2(g)$ is:

The standard enthalpies of combustion of $C_6H_{6(l)}$,$C(graphite)$ and $H_{2(g)}$ are respectively $-3270 \ kJ \ mol^{-1}$,$-394 \ kJ \ mol^{-1}$ and $-286 \ kJ \ mol^{-1}$. What is the standard enthalpy of formation of $C_6H_{6(l)}$ in $kJ \ mol^{-1}$?

Match the following allotropes of carbon with their standard enthalpy of formation $(\Delta_f H^{\Theta})$:

Allotrope	$\Delta_f H^{\Theta}$
$i$. Graphite	$b$. $0 \ kJ/mol$
$ii$. Diamond	$c$. $1.90 \ kJ/mol$
$iii$. Fullerene	$a$. $38.1 \ kJ/mol$

Which of the following values of heat of formation (in $kcal$) indicates that the product is less stable?

The heat of complete neutralization of $1 \ mol$ of $H_2SO_4$ with a strong base is ....... $Kcal$.

The heat of formation of $SiO_2$ and $MgO$ is respectively $-48.4 \ kJ$ and $-34.7 \ kJ$. The heat of the reaction $2Mg + SiO_2 \to 2MgO + Si$ is $...... \ kJ$.