Given that,$C_{(s)} + O_{2(g)} \longrightarrow CO_{2(g)} ; \Delta H^{\circ} = -x \ kJ \ mol^{-1}$ and $2CO_{(g)} + O_{2(g)} \longrightarrow 2CO_{2(g)} ; \Delta H^{\circ} = -y \ kJ \ mol^{-1}$. The enthalpy of formation of $CO$ will be:

The enthalpy change for a reaction does not depend on:

Given that $H_{2(g)} + 1/2 O_{2(g)} \to H_2O_{(g)}; \Delta H_1$ and $H_{2(g)} + 1/2 O_{2(g)} \to H_2O_{(l)}; \Delta H_2$,which of the following is correct?

The bond dissociation energy of molecules is.......

The heats of hydrogenation for $3-$-methylbutene and $2-$-pentene are $-30\, kcal/mol$ and $-28\, kcal/mol$ respectively. The heats of combustion of $2-$-methylbutane and pentane are $-784\, kcal/mol$ and $-782\, kcal/mol$ respectively. All the values are given under standard conditions. Taking into account that combustion of both alkanes gives the same products,what is $\Delta H$ (in $kcal/mol$) for the following reaction under same conditions?
$3-$-methylbutene $\rightleftharpoons$ $2-$-pentene

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