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

For which of the following reactions will the value of $\Delta H$ be positive?

If $8.84 \ kJ$ heat is liberated for the formation of $3 \ g$ of ethane,calculate its $\Delta_{f} H^{\circ}$.

Identify the law for the statement "Overall the enthalpy change for a reaction is equal to the sum of enthalpy changes of individual steps in the reaction".

When $10 \ g$ of methane is completely burnt in oxygen, the heat evolved is $560 \ kJ$. What is the heat of combustion (in $kJ \ mol^{-1}$) of methane?

The heat of neutralization of a strong acid and a strong alkali is $57.0 \, kJ \, mol^{-1}$. The heat released when $0.5 \, mol$ of $HNO_3$ solution is mixed with $0.2 \, mol$ of $KOH$ is $.... \, kJ$.