The enthalpies of combustion of carbon and carbon monoxide are $-393.5 \, kJ$ and $-283 \, kJ$ respectively. Calculate the enthalpy of formation of carbon monoxide in $kJ$. (in $.5$)

The heat of hydrogenation of cyclohexene is $28.6 \, kcal$ and that of cyclohexadiene is slightly more than double,$(55.4 \, kcal)$. What will be the heat of hydrogenation of benzene,which contains three double bonds?

Given that the heat of reaction for $A + \frac{1}{2} O_2 \to AO$ is $-50 \ kcal$ and for $AO + \frac{1}{2} O_2 \to AO_2$ is $100 \ kcal$. Find the heat of reaction for $A + O_2 \to AO_2$ in $kcal$.

Which of the following statements is correct?

The heats of combustion of carbon and carbon monoxide are $-393.5 \ kJ \ mol^{-1}$ and $-283.5 \ kJ \ mol^{-1},$ respectively. The heat of formation (in $kJ \ mol^{-1}$) of carbon monoxide per mole is:

For the reaction $Cl_{2(g)} \rightarrow 2Cl_{(g)}$,the value of $\Delta H$ is .......