Question

HO CH сн. CH2 нс HC CH3 HAC-HC CH CH CH CH d) OH OH 13. The labels have fallen off three bottles. Bottle A contains a gas, bottle B contains a liquid, and bottle C contains a solid. The labels indicate that the compounds have the same number of carbon atoms, one being an alkane, one an alcohol, and the other a carboxylic acid. Suggest the identity of the contents of each bottle, and give reasons for your explanation 14. Draw the following esters a) ethyl butanoate c) propyl 3-ethylhexanoate e) 2,3-dimethylpentyl ethanoate b) pentylpropanoate d) methyl 4-phenylpentanoate 1) butyl 3-hydroxyheptanoate 15. Name the following esters O= HC HC CH CH a) сн. b) CHE c) OH Hoc CHE o) MC CH CH₃ CH₂ HyC-C-CH d) CH, CH, сн. CH, 1) CH, 16. In what way is the functional group of an ester different from that of a carboxylic acid? How does this difference account for any differences in properties? 17. Describe the steps used to name an ester. 18. Draw the following amines a) butan-1-amine d) N-ethyl-hexan-2-amine b) pentan-2-amine e) N,N-dimethyl-pentan-3-amine c) propan-1.2-diamine f) N-methyl-N-propyl-ethanamine 19. Name the following amines CH, сн. HC сн. CH, нс, CH сн CI-CH² нс CH сн. CHHC a) NH2 b) NH NH2 HC CH2 c) HN

Answer 1

13) Alkane with 5 carbon will be gas as intermolecular forces in the compound will be very low. Alcohol with 5 carbon will be liquid. Here inter molecular forces will be intermediate due to presence of hydrogen bonding. The carboxylic acid with 5 carbon will be solid as the intermolecular forces present here are the strongest. 14) a) b Н3С. CH3 CH3 H30 ethyl butanoate pentyl propanoate d Н.С. CH3 Н.С. CH3 H2C propyl 3-ethylhexanoate methyl 4-phenylpentanoate OH CH3 f H3C. H2C. CH3 CH3 CH3 butyl 3-hydroxyheptanoate ethyl 2,3-dimethylpentanoate

15) a) methyl butanoate
b) pentyl acetate
c) 2-methylpropyl acetate
d) 2,3,3-trimethylbutan-2-yl acetate
e) ethyl hexanoate
f) butyl 2,2-dimethylpropanoate

16) Carboxylic acid contains -COOH functional group which is capable of intermolecular hydrogen bonding and also contribute to stronger intermolecular interactions.
Whereas ester contains -COOR functional group which is not capable of intermolecular hydrogen bonding. Hence this does not contribute to stronger intermolecular interactions.
This leads to relatively higher melting and boiling points of carboxylic acid as compared to ester.
Also, the relative density of acid is higher than ester.

17) i) identify the oxygen-bearing carbonyl and alcohol parts of ester.
ii) Begin the numbering of carbons of both sides of oxygen.
iii) Use Formate: [alkyl group from the alcohol part] (space) [alkane on the side with the carbonyl]
iv) Change the ending of alkane on the side with carbonyl from
-e to -oate.
v) When an ester group is attached to a ring, the ester is named as a substituent on the ring.

18) a) b) NH2 c) H3C "NH2 butan-1-amine CH3 H2C pentan-2-amine H2C "NH2 NH2 propane-1,2-diamine CH3 e) H3C CH3 f) H3C d) H2C H2C NH N-ethylhexan-2-amine H2C N-CH3 H2C CH3 N,N-dimethylpentan-3-amine N-ethyl-N-methylpropan-1-amine 19) a) 2,4-dimethylpentan-3-amine b) heptan-4-amine c) 1,4-dichlorobutane-2,3-diamine