A positive Benedict\'s test is indicated by the formation of which a. Cu2O 8. b. Cu c. Cu2+ d metallic mirror 9. Which of the following compounds upon hydrolysis would yield CH,CH,OH and CH3CH2CHO? c. CH3-CHO-CHCH3 b. d. CH3-CH-O-CHCH2 10. What is the correct IUPAC name for the following compound? CH3-CH2 CH-CH-CHs a. 3-ethylbutanoic acid b. 2-ethylbutanoic acid c. 2-pentanoic acid d. 2-ethylpentanoic acid 11. Which of the following is the structure for 2-bromopropanoic acid? a. d. CH3 CH-C-OH b. Br-CHC-o-CH3 What is the correct IUPAC name for 5-bromobenzoic acid? 12. a. 5-bromobenzoate b. 1-bromo-5-benzoic acid c. 2-bromobenzoic acid d. 3-bromobenzoic acid What is the IUPAC name of the compound shown below? 13. CH-CH-CH -O Na+ a. sodium 3-methylbutanonate b. sodium 2-methylbutanonate c. 2-methyl sodium butanonate d. 3-methyl sodium butanonate 14. The IUPAC name of the ester formed from butanoic acid and ethanol is a. butyl ethanate. b. butyl ethanonate. c. ethyl proponoate. d. ethyl butanoate.
Solution
8. (A) In the product side if formed Cu2O then it gives positive test. Enediols decrease the cupric particles (Cu 2+ ) present in Benedict reagent to cuprous particles (Cu+) which forms insoluble red copper oxide (Cu 2 O).
9. (B) on hydrolysis of ester(O) in figure B. we can get ethanol and propanal( via Tautomerism).
10. (B) as COOH is the first priority and nomenclature begin from here.
11. (D) acid group is (COOH) so naming starts from here and Bromine comes to Second Carbon position.
12. (D) since nomenclature is done through lowest carbon chain so it should be 3 bromobenzoic acid.
13. (D) counting is done from higher group (COONa) ,so methyl is attached to third carbon (C-3).
14. (D) removing (H) group from butanoic acid and (OH) from Ethanol we get ethyl butanoate
.
A positive Benedict-'s test is indicated by the formation of which a-.docx
1. A positive Benedict's test is indicated by the formation of which a. Cu2O 8. b. Cu c. Cu2+ d
metallic mirror 9. Which of the following compounds upon hydrolysis would yield CH,CH,OH
and CH3CH2CHO? c. CH3-CHO-CHCH3 b. d. CH3-CH-O-CHCH2 10. What is the correct
IUPAC name for the following compound? CH3-CH2 CH-CH-CHs a. 3-ethylbutanoic acid b. 2-
ethylbutanoic acid c. 2-pentanoic acid d. 2-ethylpentanoic acid 11. Which of the following is the
structure for 2-bromopropanoic acid? a. d. CH3 CH-C-OH b. Br-CHC-o-CH3 What is the correct
IUPAC name for 5-bromobenzoic acid? 12. a. 5-bromobenzoate b. 1-bromo-5-benzoic acid c. 2-
bromobenzoic acid d. 3-bromobenzoic acid What is the IUPAC name of the compound shown
below? 13. CH-CH-CH -O Na+ a. sodium 3-methylbutanonate b. sodium 2-methylbutanonate c.
2-methyl sodium butanonate d. 3-methyl sodium butanonate 14. The IUPAC name of the ester
formed from butanoic acid and ethanol is a. butyl ethanate. b. butyl ethanonate. c. ethyl
proponoate. d. ethyl butanoate.
Solution
8. (A) In the product side if formed Cu2O then it gives positive test. Enediols decrease the cupric
particles (Cu 2+
) present in Benedict reagent to cuprous particles (Cu+) which forms insoluble
red copper oxide (Cu 2 O).
9. (B) on hydrolysis of ester(O) in figure B. we can get ethanol and propanal( via Tautomerism).
10. (B) as COOH is the first priority and nomenclature begin from here.
11. (D) acid group is (COOH) so naming starts from here and Bromine comes to Second Carbon
position.
12. (D) since nomenclature is done through lowest carbon chain so it should be 3 bromobenzoic
acid.
13. (D) counting is done from higher group (COONa) ,so methyl is attached to third carbon (C-
3).
14. (D) removing (H) group from butanoic acid and (OH) from Ethanol we get ethyl butanoate
