Question

Given: C + O2 → CO2 Bond Bond Energy (kJ/mol) C=O 799 O=O 494 Calculate the enthalpy change for the chemical reaction. The change in enthalpy for the given reaction is kilojoules.

Answer 1

First of all, let us write this Reaction in its whole structural form.

C + O = O   ---------⇒ O = C = O

Now, we know the Formula for the Enthaly Change.

Enthalpy Change = Enthalpy of the Formation of Products - Enthalpy of the Formation of Reactants.

Enthalpy of Formation of C = 0 [As per as the IUPAC Rules, for the free state of the elements, Enthaly Change is zero.]

Enthalpy of Formation of O = C = O = 2 × 799

∴ Enthalpy Change = 2 × 799 - (0 + 494)

= 1104 kJ/mole.

Hope it helps.