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 $, kg$)

Equal volumes of methanoic acid and sodium hydroxide are mixed. If $x$ is the heat of formation of water,then the heat evolved on neutralization is

Given
$N_{2(g)} + 3H_{2(g)} \longrightarrow 2NH_{3(g)} \quad \Delta_{r}H^{\theta} = -92.4 \, kJ \, mol^{-1}$
What is the standard enthalpy of formation of $NH_{3}$ gas?

The enthalpy of atomization of $PH_3(g)$ is $228 \, kcal \, mol^{-1}$ and that of $P_2H_4(g)$ is $355 \, kcal \, mol^{-1}$. The $P-P$ bond energy (in $kcal \, mol^{-1}$) is:

If the standard heat of the reaction $Fe_2O_{3(s)} + 3CO_{(g)} = 2Fe_{(s)} + 3CO_{2(g)}$ is $-6.6 \, kcal$,then $\Delta H_f^o$ for $Fe_2O_{3(s)}$ is $...... \, kcal/mol$. [Given: $\Delta H_f^o$ of $CO_{(g)} = -26.4 \, kcal$ and $\Delta H_f^o$ of $CO_{2(g)} = -94 \, kcal$]

The $H-H$ bond energy is $430 \ kJ \ mol^{-1}$ and $Cl-Cl$ bond energy is $240 \ kJ \ mol^{-1}$. $\Delta H$ for the formation of $HCl$ is $-90 \ kJ \ mol^{-1}$. The $H-Cl$ bond energy is about: