101. Which of the following is a characteristic property of alcohols?
a) High boiling points
b) Low solubility in water
c) Non-polar nature
d) They do not participate in hydrogen bonding
Answer: a) High boiling points
Explanation: Alcohols have high boiling points compared to hydrocarbons of similar molecular weight due to hydrogen bonding between alcohol molecules.
102. What is the main product when a primary alcohol undergoes oxidation?
a) Ketone
b) Aldehyde
c) Carboxylic acid
d) Ester
Answer: c) Carboxylic acid
Explanation: Primary alcohols can be oxidized to form carboxylic acids upon complete oxidation.
103. Which of the following statements is true regarding phenols?
a) Phenols are stronger acids than alcohols.
b) Phenols do not undergo electrophilic substitution.
c) Phenols cannot form hydrogen bonds.
d) Phenols are completely non-polar.
Answer: a) Phenols are stronger acids than alcohols.
Explanation: Phenols are indeed stronger acids than alcohols because the resulting phenoxide ion is stabilized by resonance.
104. Which of the following is used as a dehydrating agent to convert alcohols to alkenes?
a) H₂O
b) H₂SO₄
c) NaOH
d) HCl
Answer: b) H₂SO₄
Explanation: Sulfuric acid (H₂SO₄) is commonly used as a dehydrating agent in the elimination reaction to convert alcohols into alkenes.
105. Which of the following compounds is a tertiary alcohol?
a) 1-Butanol
b) 2-Butanol
c) 2-Methyl-2-propanol
d) 3-Pentanol
Answer: c) 2-Methyl-2-propanol
Explanation: 2-Methyl-2-propanol (tert-butyl alcohol) is a tertiary alcohol, as the hydroxyl group is attached to a carbon that is bonded to three other carbon atoms.
106. What happens when a secondary alcohol is treated with potassium dichromate (K₂Cr₂O₇)?
a) It gets oxidized to an aldehyde.
b) It gets oxidized to a ketone.
c) It remains unchanged.
d) It gets reduced to an alcohol.
Answer: b) It gets oxidized to a ketone.
Explanation: Secondary alcohols are oxidized by potassium dichromate to form ketones.
107. Which of the following alcohols is most soluble in water?
a) Butanol
b) Propanol
c) Octanol
d) Methanol
Answer: d) Methanol
Explanation: Methanol is the most soluble in water due to its small size and ability to form hydrogen bonds with water.
108. Which reaction involves the conversion of alcohols to ethers?
a) Esterification
b) Dehydration
c) Williamson ether synthesis
d) Hydrolysis
Answer: c) Williamson ether synthesis
Explanation: The Williamson ether synthesis involves the reaction of an alkoxide ion with a primary alkyl halide to form an ether.
109. What is the main difference between phenols and alcohols?
a) Phenols are aromatic compounds, while alcohols are not.
b) Phenols are less acidic than alcohols.
c) Alcohols cannot form hydrogen bonds.
d) Phenols do not have a hydroxyl group.
Answer: a) Phenols are aromatic compounds, while alcohols are not.
Explanation: Phenols contain a hydroxyl group attached to an aromatic ring, while alcohols contain a hydroxyl group attached to a non-aromatic carbon chain.
110. Which alcohol is produced when 2-butanol is dehydrated?
a) 1-Butene
b) 2-Butene
c) 3-Butene
d) 2-Butanol remains unchanged.
Answer: b) 2-Butene
Explanation: Dehydration of 2-butanol primarily produces 2-butene through an elimination reaction.
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