a) Define the Bond Dissociation Enthalpy of a bond.

b) How does the bond dissociation enthalpy differ from the mean bond enthalpy?

c) The Enthalpy of Atomization of methane, CH4, is 1663 kJ mol-1, while that for chloromethane, CH3Cl, is 1574 kJ mol-1.

i) Explain what is meant by the Enthalpy of Atomization of a substance, using methane as an example.

ii) Use the information given to calculate approximate bond enthalpies for a C-H and a C-Cl bond.

d) Use the mean bond enthalpies below to determine enthalpy of reaction for the following reactions:

i) CH3CH2CH=CH2(g) + HCl(g) CH3CH2CHClCH3(g)

ii) CH3CH2CH3(g) + Cl2(g) CH3CH2CH2Cl(g) + HCl(g)

Bond	Mean Bond Enthalpy / kJ mol-1
C-H	413
Cl-Cl	242
H-Cl	431
C-Cl	338
C=C	612
C-C	348

e) In the reaction in d) ii), CH3CHClCH3 is also produced. Explain whether your calculation would have given a different result for this isomeric product.