$C(\text{diamond}) + O_{2(g)} \to CO_{2(g)}; \Delta H = -395 \text{ kJ}$
$C(\text{graphite}) + O_{2(g)} \to CO_{2(g)}; \Delta H = -393.5 \text{ kJ}$
If graphite is converted into diamond,then the $\Delta H$ for the process is . . . . . . $\text{kJ}$.

The enthalpy change of which reaction corresponds to $\Delta H_f^o$ for $Na_2CO_{3(s)}$ at $298 \ K$?

What will be the enthalpy of formation of benzene in $kJ$ for the reaction: $6C_{(s)} + 3H_{2(g)} \rightarrow C_6H_{6(l)}$? Given that the enthalpy of combustion of benzene is $-3268 \ kJ$, the enthalpy of formation of $CO_{2(g)}$ is $-393.5 \ kJ$, and the enthalpy of formation of $H_2O_{(l)}$ is $-285.8 \ kJ$.

$A$,$B$,$C$ 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?
$A_{(g)} + 3B_{(g)} \longrightarrow C_{(g)} + 3D_{(g)}$

Equal volumes of molar hydrochloric acid and sulphuric acid are neutralized by dilute $NaOH$ solution and $x \ kcal$ and $y \ kcal$ of heat are liberated respectively. Which of the following is true?

The value of ${\Delta _f}{H^o}$ for $HgO$ is $-90.5 \, kJ \, mol^{-1}$. The amount of $Hg$ produced thermally from $HgO$ by $1600 \, kJ$ of heat is ......... (in $, kg$)