Page 288 - Theory and Problems of BEGINNING CHEMISTRY

CHAP. 18] ORGANIC CHEMISTRY 277

18.33. Explain which hydrogen atom on ethanoic acid, CH 3 CO 2 H, has acidic properties.
Ans. The hydrogen atom attached to the oxygen atom is ionizable.

18.34. Since hexanoic acid is C 5 H 11 CO 2 H, what is the formula for pentanoic acid?
Ans. C 4 H 9 CO 2 H

18.35. The mild oxidation and moderate oxidation of CH 3 CH 2 OH are described in the text. What are the products
of the vigorous oxidation of CH 3 CH 2 OH with excess oxygen gas?
Ans. CO 2 and H 2 O

18.36. Write balanced chemical equations for the reaction of CH 3 CO 2 H with (a)CH 3 OH, (b)CH 3 CH 2 OH,
(c)CH 3 CH 2 CH 2 OH, (d)CH 3 CH 2 CH 2 CH 2 OH, and (e) explain the utility of the symbol R.
Ans. (a) CH 3 OH + HOCOCH 3 −→ CH 3 OCOCH 3 + H 2 O
(b) CH 3 CH 2 OH + HOCOCH 3 −→ CH 3 CH 2 OCOCH 3 + H 2 O
(c) CH 3 CH 2 CH 2 OH + HOCOCH 3 −→ CH 3 CH 2 CH 2 OCOCH 3 + H 2 O
(d)CH 3 CH 2 CH 2 CH 2 OH + HOCOCH 3 −→ CH 3 CH 2 CH 2 CH 2 OCOCH 3 + H 2 O
(e) Each of these reactions corresponds to the equation below. The fact that all four of these and many
more can be represented by this single equation makes R a useful representation.
ROH + HOCOCH 3 −→ ROCOCH 3 + H 2 O

18.37. Ethyl acetate is reduced by hydrogen in the presence of a catalyst to yield one organic compound that
contains oxygen but is not an ether. What is the compound?
Ans. CH 3 CH 2 OH

AMINES
18.38. Write the formulas for (a) ammonium chloride, (b) methyl ammonium chloride, (c) dimethyl ammonium
chloride, (d) trimethyl ammonium chloride, and (e) tetramethyl ammonium chloride.
Ans. (a) NH 4 Cl.
(b) CH 3 NH 3 Cl. (One H atom has been replaced by a CH 3 group.)
(c) (CH 3 ) 2 NH 2 Cl. (Two H atoms have been replaced by CH 3 groups.)
(d) (CH 3 ) 3 NHCl. (Three H atoms have been replaced by CH 3 groups.)
(e) (CH 3 ) 4 NCl. (All four H atoms have been replaced by CH 3 groups.)

18.39. Write balanced chemical equations for the reaction with H 3 O (excess) of aqueous (a)NH 3 ,(b)CH 3 NH 2 ,
+
and (c)NH 2 CH 2 CH 2 NH 2 .
Ans. (a) H 3 O + NH 3 −→ NH 4 + H 2 O
+
+
(b) H 3 O + CH 3 NH 2 −→ CH 3 NH 3 + H 2 O
+
+
(c) 2 H 3 O + NH 2 CH 2 CH 2 NH 2 −→ + NH 3 CH 2 CH 2 NH 3 + 2H 2 O
+
+
AMIDES
18.40. What amide is the product of the reaction of CH 3 CO 2 H and CH 3 CH 2 NH 2 ?
Ans. CH 3 CONHCH 2 CH 3

18.41. Write line formulas for all amides that are isomers of dimethylmethanamide.
Ans. Dimethylmethanamide is HCON(CH 3 ) 2 . The possible isomers are CH 3 CONHCH 3 and CH 3 CH 2 CONH 2 .