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 $, kg$)

$S_{\text{(rhombic)}} + O_{2(g)} \rightarrow SO_{2(g)}; \Delta H = -297.5 \, kJ$
$S_{\text{(monoclinic)}} + O_{2(g)} \rightarrow SO_{2(g)}; \Delta H = -300 \, kJ$
From the given data,which of the following statements is correct?

If the heat of neutralization of an acid-base reaction is $56 \ kJ \ mol^{-1}$,then the substances could be:

In which of the following neutralisation reactions,the heat of neutralisation will be highest?

If $C_{(s)} + O_{2(g)} \rightarrow CO_{2(g)}$,$\Delta H = -X$,and $CO_{(g)} + \frac{1}{2} O_{2(g)} \rightarrow CO_{2(g)}$,$\Delta H = -Y$,calculate $\Delta_f H$ for $CO_{(g)}$ formation.

Calculate the standard enthalpy change of the reaction: $C_2H_{2(g)} + \frac{5}{2}O_{2(g)} \rightarrow 2CO_{2(g)} + H_2O_{(\ell)}$ given the following standard enthalpies of formation:
$\Delta_fH^{\circ}(CO_2) = -393 \ kJ \ mol^{-1}$
$\Delta_fH^{\circ}(H_2O) = -286 \ kJ \ mol^{-1}$
$\Delta_fH^{\circ}(C_2H_2) = 227 \ kJ \ mol^{-1}$