Given that a chlorine-oxygen bond has an enthalpy of 243 kJ/mol , an oxygen-oxygen bond has an enthalpy of 498 kJ/mol , and the standard enthalpy of formation of ClO2 102.5 kJ/mol , calculate the value for the enthalpy of formation per mole of ClO(g). What is the value for the enthalpy of formation per mole of ClO(g)? Enter your answer numerically, in terms of kJ, and to three significant figures.

Respuesta :

Answer:

Enthalpy of formation of ClO (ΔHf⁰) = 96.5 Kj/mole

Explanation:

Given that

chlorine-oxygen bond has an enthalpy of 243 kJ/mole , an oxygen-oxygen bond has an enthalpy of 498 kJ/mole.

                       [tex]\frac{1}{2}[/tex][tex]Cl_{2}[/tex](g) + [tex]\frac{1}{2} O_{2}[/tex](g) → ClO(g)

ΔHr = ∑ Bond energies

       =  [tex]\frac{1}{2}[/tex] x (Bond enthalpy of oxygen) - (Bond enthalpy of Cl - O bond)

       =  [tex]\frac{1}{2}[/tex] x 498 kj/mole  - 243 kj/mole

        = + 6 kj/mole

                                    ClO(g) + [tex]\frac{1}{2} O_{2}[/tex](g) → ClO₂ (g)

          ΔHr = Enthalpy of formation of ClO₂ - Enthalpy of formation of ClO

⇒Enthalpy of formation of ClO = Enthalpy of formation of ClO₂ - ΔHr

⇒Enthalpy of formation of ClO = 102.5 kj/mole - 6 kj/mole

Enthalpy of formation of ClO = 96.5 kj/mole