The enthalpy of combustion of propane,graphite and dihydrogen at $298 \ K$ are: $-2220.0 \ kJ \ mol^{-1}$,$-393.5 \ kJ \ mol^{-1}$ and $-285.8 \ kJ \ mol^{-1}$ respectively. The magnitude of the enthalpy of formation of propane $(C_{3}H_{8})$ is ......... $kJ \ mol^{-1}$. (Nearest integer)

The $\Delta H_f^o$ for $CO_{2(g)}$,$CO_{(g)}$ and $H_2O_{(g)}$ are $-393.5$,$-110.5$ and $-241.8 \ kJ \ mol^{-1}$ respectively. The standard enthalpy change (in $kJ$) for the reaction $CO_{2(g)} + H_{2(g)} \to CO_{(g)} + H_2O_{(g)}$ is

Find the standard enthalpy of formation of ammonia from the following reaction:
$N_{2(g)} + 3H_{2(g)} \rightarrow 2NH_{3(g)} ; \Delta_{r}H^0 = -92.0 \ kJ$

The enthalpy changes for the following reactions are given:
$Cl_{2(g)} = 2Cl_{(g)}, 242.3 \, kJ \, mol^{-1}$; $I_{2(g)} = 2I_{(g)}, 151.0 \, kJ \, mol^{-1}$
$ICl_{(g)} = I_{(g)} + Cl_{(g)}, 211.3 \, kJ \, mol^{-1}$; $I_{2(s)} = I_{2(g)}, 62.76 \, kJ \, mol^{-1}$
Given that the standard states of iodine and chlorine are $I_{2(s)}$ and $Cl_{2(g)}$,the standard enthalpy of formation for $ICl_{(g)}$ is $...... \, kJ \, mol^{-1}$.

The heats of combustion of rhombic and monoclinic sulphur are respectively $70960 \ cal$ and $71030 \ cal$. What will be the heat of conversion of rhombic sulphur to monoclinic? $(cal)$

The heat of neutralization of $HCl$ by $NaOH$ is $-57.3 \, kJ/mol$. If the heat of neutralization of $HCN$ by $NaOH$ is $-12.1 \, kJ/mol$,then the enthalpy of dissociation of $HCN$ is $...... \, kJ$.