110. Why is ortho-nitrophenol less soluble in water than its meta and para isomers?
[AIEEE Chemistry — 2012]
(A) It is more steam-volatile
(B) It has intramolecular hydrogen bonding
(C) It has greater intermolecular hydrogen bonding
(D) It has a lower melting point
Answer: (B) It has intramolecular hydrogen bonding
Explanation: Ortho-nitrophenol can form an intramolecular hydrogen bond between its neighbouring hydroxyl and nitro groups. That internal interaction reduces its tendency to hydrogen-bond with surrounding water. Meta and para isomers are more available for intermolecular hydrogen bonding and are relatively more soluble.
109. Aspirin is chemically known as what?
[AIEEE Chemistry — 2012]
(A) Acetylsalicylic acid
(B) Phenyl salicylate
(C) Acetyl salicylate
(D) Methylsalicylic acid
Answer: (A) Acetylsalicylic acid
Explanation: Aspirin is acetylsalicylic acid, an acetylated derivative of salicylic acid. It contains an aromatic ring, a carboxylic acid and an ester group. Aspirin has analgesic and antipyretic actions and can also inhibit platelet aggregation at appropriate doses.
108. Formaldehyde among the products of alkene ozonolysis confirms the presence of which structural feature?
[AIEEE Chemistry — 2011]
(A) Terminal vinyl group
(B) Isopropyl group
(C) Acetylenic triple bond
(D) Two internal carbon-carbon double bonds
Answer: (A) Terminal vinyl group
Explanation: Ozonolysis cleaves carbon-carbon double bonds to give carbonyl compounds. A terminal methylene unit, CH₂=, produces formaldehyde after reductive work-up. Thus the observation indicates a terminal alkene or vinyl-type structural group rather than merely an isopropyl group or an alkyne.
107. Which material among the following is a polyester?
[AIPMT Prelims Chemistry — 2011]
(A) Terylene
(B) Bakelite
(C) Melamine
(D) Nylon-6,6
Answer: (A) Terylene
Explanation: Terylene, also known as PET or Dacron, contains recurring ester linkages formed from ethylene glycol and terephthalic acid. Nylon-6,6 is a polyamide, whereas Bakelite and melamine resins are generally cross-linked thermosetting polymers. Polyester classification depends on the ester bonds in the backbone.
106. Which one is used as an antihistamine?
[AIPMT Prelims Chemistry — 2011]
(A) Chloramphenicol
(B) Diphenhydramine
(C) Norethindrone
(D) Omeprazole
Answer: (B) Diphenhydramine
Explanation: Diphenhydramine blocks histamine H1 receptors and is used to relieve allergy symptoms. Chloramphenicol is an antibiotic, norethindrone is a progestin and omeprazole reduces gastric acid secretion. Their distinct organic functional groups support different biological targets and therapeutic applications.
105. Reaction of phenol with a potassium bromide–potassium bromate mixture gives chiefly which brominated phenol?
[AIEEE Chemistry — 2011]
(A) 3-Bromophenol
(B) 4-Bromophenol
(C) 2,4,6-Tribromophenol
(D) 2-Bromophenol
Answer: (C) 2,4,6-Tribromophenol
Explanation: Phenol strongly activates its aromatic ring by resonance donation from the hydroxyl group. Brominating species generated from the listed reagents can therefore substitute at both ortho positions and the para position, producing 2,4,6-tribromophenol under the stated conditions.
104. Which of these compounds is the strongest acid?
[AIEEE Chemistry — 2011]
(A) Formic acid
(B) 2-Chlorobutanoic acid
(C) 4-Chlorobutanoic acid
(D) Acetic acid
Answer: (B) 2-Chlorobutanoic acid
Explanation: An electronegative chlorine substituent withdraws electron density through the sigma-bond framework. Its acid-strengthening effect is greatest when chlorine lies adjacent to the carboxyl group. Thus 2-chlorobutanoic acid is more acidic than the distant 4-chloro isomer and unsubstituted acids.
103. What is obtained by reacting sodium ethoxide with acetyl chloride?
[AIEEE Chemistry — 2011]
(A) Butan-2-one
(B) Ethyl chloride
(C) Ethyl ethanoate
(D) Diethyl ether
Answer: (C) Ethyl ethanoate
Explanation: Ethoxide ion attacks the carbonyl carbon of acetyl chloride. Chloride is expelled through nucleophilic acyl substitution, creating the ester ethyl ethanoate, also called ethyl acetate. This is an ester-forming reaction of an acyl chloride with an alkoxide.
102. Which alcohol is formed when chloral (CCl₃CHO) undergoes the Cannizzaro reaction in strong alkali?
[AIEEE Chemistry — 2011]
(A) Trichloromethanol
(B) 2,2,2-Trichloropropanol
(C) Chloroform
(D) 2,2,2-Trichloroethanol
Answer: (D) 2,2,2-Trichloroethanol
Explanation: Chloral lacks an alpha hydrogen suitable for an aldol condensation and can undergo Cannizzaro disproportionation. One chloral molecule gives a trichloroacetate salt, while another is reduced to trichloroethanol, CCl₃CH₂OH, through intermolecular hydride transfer.
101. What is formed when glycerol is treated with excess hydrogen iodide?
[AIPMT Mains Chemistry — 2010]
(A) 2-Iodopropane
(B) Allyl iodide
(C) Propene
(D) Glycerol triiodide
Answer: (A) 2-Iodopropane
Explanation: Excess hydrogen iodide can replace and reduce the hydroxyl-containing framework of glycerol under strongly reducing conditions. The net transformation gives 2-iodopropane in the examination scheme. The reaction should not be confused with simple single-step substitution of every hydroxyl group by iodine.
