If the enthalpy of combustion of carbon to $CO_{2(g)}$ is $-394.0 \ kJ \ mol^{-1}$,the enthalpy change for the formation of $17.6 \ g$ of $CO_2$ from carbon and dioxygen at the same temperature in $kJ$ is:

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

Average $C-H$ bond energy is $416 \ kJ \ mol^{-1}$. Which of the following is correct?

The $\Delta_f H^{\circ}$ of $AO_{(s)}$,$BO_{2(g)}$ and $ABO_{3(s)}$ is $-635$,$x$ and $-1210 \ kJ \ mol^{-1}$ respectively.
$ABO_{3(s)} \rightarrow AO_{(s)} + BO_{2(g)} ; \Delta_r H^{\circ} = 175 \ kJ \ mol^{-1}$.
What is the value of $x$ (in $kJ \ mol^{-1}$) ?

What is the value of $\Delta H^{\circ}$ for the formation of ethanol from ethene gas and liquid water from the following data (in $kJ$)?
$(i)$ $C_2H_5OH_{(l)} + 3O_{2_{(g)}} \longrightarrow 2CO_{2_{(g)}} + 3H_2O_{(l)}$ $\Delta H^{\circ} = -1368 \ kJ$
$(ii)$ $C_2H_{4_{(g)}} + 3O_{2_{(g)}} \longrightarrow 2CO_{2_{(g)}} + 2H_2O_{(l)}$ $\Delta H^{\circ} = -1410 \ kJ$

If the ratio of bond dissociation energies of $XY$,$X_2$,and $Y_2$ is $1 : 1 : 0.5$ and the enthalpy of formation of $XY$ is $\Delta_f H = -200 \ kJ \ mol^{-1}$,then the bond dissociation energy of $X_2$ in $kJ \ mol^{-1}$ is: