Alkanes and Cycloalkanes; Conformational and Geometric Isomerism - Cengage Learning - page 24

CH 3 Br bromomethane (methyl bromide)

CH 2 Br 2 dibromomethane (methylene bromide)

CHBr 3 tribromomethane (bromoform)

CBr 4 tetrabromomethane (carbon tetrabromide)

2.20

2.21 Four monobrominated products can be obtained from heptane, but only one

monobrominated product is obtained from cycloheptane.

2.22 Yes. All the hydrogens are equivalent, and monobromination gives a single product.

2.23 Add the reactants and the products of eqs. 2.16 and 2.17:

R H +Cl R + H Cl (2.16)

R + Cl Cl R Cl +Cl (2.17)

R H +Cl +R + Cl Cl R Cl +Cl +R + H l

The intermediate radicals ( R and Cl ) cancel and what is left is eq. 2.9:

R H + Cl l R Cl + H l (2.9)

2.24 initiation

heat or light

Cl Cl 2Cl

propagation CH 4 +Cl CH 3 + HCl

CH 3 +Cl Cl CH 3 Cl + l

termination

2 Cl Cl Cl

2CH 3 CH 3 CH 3

CH 3 +Cl CH 3 Cl

2.25 The second termination step in the answer to Problem 2.24 accounts for the

formation of ethane in the chlorination of methane. Ethane can also be chlorinated,
which explains the formation of small amounts of chloroethane in this reaction.