Use the enthalpy data for the two halogenation reactions of methane below to…

CHEMISTRY · Subjective · A Level · Chemistry · Energetics · Energetics

Problem

Use the enthalpy data for the two halogenation reactions of methane below to determine the average bond energies of the

\text{C--Cl}

and

\text{C--Br}

bonds. 1.

\text{CH}_4(g)+\text{Cl}_2(g)\rightarrow\text{CH}_3\text{Cl}(g)+\text{HCl}(g)\quad \Delta H_1= -104\,\text{kJ}

\text{CH}_4(g)+\text{Br}_2(g)\rightarrow\text{CH}_3\text{Br}(g)+\text{HBr}(g)\quad \Delta H_2= -68\,\text{kJ}

Average bond energies provided:

\text{C--H}: 413\,\text{kJ mol}^{-1}

\text{Cl--Cl}: 243\,\text{kJ mol}^{-1}

\text{Br--Br}: 193\,\text{kJ mol}^{-1}

\text{H--Cl}: 432\,\text{kJ mol}^{-1}

\text{H--Br}: 366\,\text{kJ mol}^{-1}

Report the values of

E_{\text{C--Cl}}

and

E_{\text{C--Br}}

\text{kJ mol}^{-1}

, separated by a comma.