# Given 2CO(g) + O_2(g) rarr 2CO_2(g) DeltaH^@=-564*kJ*mol^-1...what is the enthalpy associated with the formation of a mass of 44.0*g of carbon dioxide by these means?

$\Delta {H}^{\circ} = - 282 \cdot k J$
${\text{2CO +O"_2rarr"2CO}}_{2}$ ;DeltaH^@=-564*kJ*mol^-1
$\Delta {H}^{\circ}$ is always quoted per mole of reaction as written. That is synthesis of 2 moles of carbon dioxide from 2 moles of carbon monoxide and stoichiometric dioxygen has an associated enthalpy change of $- 564 \cdot k J$. Because we combusted 1 mole of carbon monoxide, rather than 2 moles as specified in the equation, the enthalpy calculation is modified and HALVED.........