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Solutions for The Study of Chemical Reactions
CH3CH2CH(CH3)2 (CH3)3CCH2CH339 (a)
1° 2° 3° 1°
(b)
1° 2° 1°
1°
3°
(c)
All are 2° H except for the
two types labeled.
(d)
3°
1°
All are 2° H except for the
two types labeled.
(e) 3°
All are 2° H except as labeled.
(a) break H–CH2CH3 and I–I, make I–CH2CH3 and H–I
kJ/mole: ( + 410 + + 151) + ( − 222 + − 297) = + 42 kJ/mole
kcal/mole: ( + 98 + + 36) + ( − 53 + − 71) = + 10 kcal/mole
(b) break CH3CH2–Cl and H–I, make CH3CH2–I and H–Cl
kJ/mole: ( + 339 + + 297) + ( − 222 + − 431) = − 17 kJ/mole
kcal/mole: ( + 81 + + 71) + ( − 53 + − 103) = − 4 kcal/mole
(c) break (CH3)3C–OH and H–Cl, make (CH3)3C–Cl and H–OH
kJ/mole: ( + 381 + + 431) + ( − 331 + − 498) = − 17 kJ/mole
kcal/mole: ( + 91 + + 103) + ( − 79 + − 119) = − 4 kcal/mole
(d) break CH3CH2–CH3 and H–H, make CH3CH2–H and H–CH3
kJ/mole: ( + 356 + + 435) + ( − 410 + − 435) = − 54 kJ/mole
kcal/mole: ( + 85 + + 104) + ( − 98 + − 104) = − 13 kcal/mole
(e) break CH3CH2–OH and H–Br, make CH3CH2–Br and H–OH
kJ/mole: ( + 381 + + 368) + ( − 285 + − 498) = − 34 kJ/mole
kcal/mole: ( + 91 + + 88) + ( − 68 + − 119) = − 8 kcal/mole
40
C
CH3
H
CH2CH3CH3C
H3C
H
2°
3°
CH3
H
HH
H
H
H
H H
H
1°
CH3
H
H
H
H H
H
H
H
H
H H 3°
1°
H CH3
CH3
H
H
H
H
H
CH3
CH3H
H
3°
1°
1°
1°
1°
(f)
CH2
CH3
CH2 CHCH2
Cl
CH2Cl
(CH3)3C
CH3
Cl
(CH3)2CH CH3CH2
CH3
Cl
CH3
CH3
Cl
41 Numbers are bond dissociation energies in kcal/mole in the top line and kJ/mole in the bottom line.
> > > > >
 85
356
 87
364
 91
381
 95
397
 98
410
104
435
most stable least stable
+++(b)
Only one product; chlorination would work. Bromination on a 2° 
carbon would not be predicted to be a high-yielding process.
42
(a)
Chlorination would produce four constitutional isomers and would not be a good method to make only one 
of these. Monobromination at the 3° carbon would give a reasonable yield of the pure 3° bromide, in 
contrast to the results from chlorination.
benzyl allyl 3° 1°2° methyl
84