NEET Chemistry: Alcohols phenols and ethers Practice Questions
14 free multiple-choice questions on Alcohols phenols and ethers (Organics containing Oxygen) for NEET Chemistry, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. Which among the following functional groups generally exhibits the highest degree of acidity compared to alcohols and ethers?
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Correct answer: B — Phenols
Phenols are significantly more acidic than alcohols and ethers because the resulting phenoxide ion is stabilized by resonance involving the aromatic ring. This stabilization lowers the energy of the conjugate base, making the release of the proton easier.
Q2. Which of the following functional groups generally exhibits the highest degree of acidic character compared to simple alcohols?
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Correct answer: A — Phenols
Phenols are more acidic than alcohols because the resulting phenoxide ion is stabilized by resonance involving the benzene ring, leading to greater stability compared to the alkoxide ion derived from alcohols.
Q3. The ability of an alcohol to form hydrogen bonds with itself is primarily due to the presence of which functional group?
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Correct answer: C — Hydroxyl group
The hydroxyl (O-H) group in alcohols allows for the formation of strong intermolecular hydrogen bonds, which is responsible for their relatively high boiling points.
Q4. The reaction of phenol with bromine water (Br₂/H₂O) results in the substitution of the hydrogen atom at the ortho and para positions. This reaction is characteristic of which type of reaction?
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Correct answer: A — Electrophilic substitution
Phenols undergo electrophilic substitution reactions easily because the hydroxyl group activates the benzene ring, making it susceptible to electrophilic attack.
Q5. Which of the following compounds possesses a structure where oxygen is bonded to two alkyl groups, making it an ether?
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Correct answer: B — Diethyl ether
Diethyl ether is an ether formed by the linkage of two alkyl groups (ethyl groups) via an oxygen atom, fitting the definition of an ether. 1-Propanol is an alcohol, Phenol is a phenol, and Ethanal is an aldehyde.
Q6. The compound CH3CH2OH undergoes dehydration upon heating to form an alkene. What type of reaction is this?
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Correct answer: A — Elimination reaction
Dehydration of alcohols, especially when initiated by heating, typically results in the elimination of water to form an alkene, which is an elimination reaction.
Q7. Which compound among the following has the highest boiling point due to the presence of intermolecular hydrogen bonding?
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Correct answer: A — Ethanol
Ethanol exhibits stronger intermolecular hydrogen bonding compared to the other options (methanol, ethanal, phenol in this context), leading to a higher boiling point among the choices.
Q8. Which functional group is characteristic of an alcohol?
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Correct answer: C — C-O-H
Alcohols are characterized by the presence of a hydroxyl group (-OH) attached to a saturated carbon atom.
Q9. When comparing alcohols and phenols, the reason for the lower boiling point of phenol (compared to ethanol of similar molecular mass) is primarily due to:
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Correct answer: B — Lack of O-H hydrogen bonding in phenol (due to resonance stabilization of the lone pair)
Phenol exhibits weaker intermolecular hydrogen bonding compared to alcohols because the oxygen lone pair is delocalized into the benzene ring via resonance, making the molecule less able to form strong H-bonds with itself.
Q10. When an alcohol is treated with sodium metal (Na), the resulting product is:
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Correct answer: A — An alkoxide
Alcohols react with sodium metal to form sodium alkoxides (R-O⁻Na⁺), which are the sodium salts of the alcohols.
Q11. Which functional group among the following exhibits the highest degree of acidity in general?
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Correct answer: A — Phenols
Phenols are more acidic than alcohols because the resulting phenoxide ion is stabilized by resonance, whereas alcohols do not possess this extensive resonance stabilization of the conjugate base.
Q12. Which of the following compounds is an ether?
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Correct answer: B — Diethyl ether
Diethyl ether is an ether, formed from the reaction of ethanol and ethanol. Ethanol and phenol are alcohols, and propan-2-ol is an alcohol.
Q13. Which reaction is typically used to prepare an ether from two alcohols?
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Correct answer: A — Williamson Ether Synthesis
The Williamson Ether Synthesis involves the reaction of an alkoxide ion (or alkyl halide) with an alcohol, which is a common method for synthesizing ethers.
Q14. Phenols are more acidic than alcohols because:
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Correct answer: C — The resonance structure allows the phenoxide ion to be stabilized by resonance.
The negative charge on the phenoxide ion is delocalized over the benzene ring via resonance, making it more stable (and thus the acid stronger) compared to the alkoxide ion of alcohols.
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