Chapter-7 Alcohols — Online MCQ Test
CHEMISTRY · CLASS 12 SECOND PUC · Karnataka State Board
Practice Chapter-7 Alcohols with a free chapter-wise online MCQ test.
This chapter covers: Phenols and Ethers.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-7 Alcohols — Important Questions & Answers
What is the general formula for alcohols?
- A. CnH2n+2O
- B. CnH2nO
- C. CnH2n-2O
- D. CnH2n+4O
Answer: A. CnH2n+2O
Alcohols have the general formula CnH2n+2O, where one hydrogen atom is replaced by an -OH group in alkanes.
Alcohols have the general formula CnH2n+2O, where one hydrogen atom is replaced by an -OH group in alkanes.
Which functional group is characteristic of alcohols?
- A. -CHO
- B. -OH
- C. -COOH
- D. -C=O
Answer: B. -OH
The hydroxyl group (-OH) is the characteristic functional group of alcohols, bonded to a carbon atom.
The hydroxyl group (-OH) is the characteristic functional group of alcohols, bonded to a carbon atom.
Which statement about phenols is correct?
- A. Phenols are more acidic than alcohols
- B. Phenols are less acidic than alcohols
- C. Phenols and alcohols have the same acidity
- D. Phenols show no acidic properties
Answer: A. Phenols are more acidic than alcohols
Phenols are significantly more acidic than alcohols due to the resonance stabilization of the phenoxide ion formed after deprotonation.
Phenols are significantly more acidic than alcohols due to the resonance stabilization of the phenoxide ion formed after deprotonation.
Which alcohol shows the highest boiling point for a given molecular weight?
- A. Primary alcohol
- B. Secondary alcohol
- C. Tertiary alcohol
- D. All show the same boiling point
Answer: A. Primary alcohol
Primary alcohols have the most hydrogen bonding capacity due to less steric hindrance, resulting in higher boiling points compared to secondary and tertiary alcohols.
Primary alcohols have the most hydrogen bonding capacity due to less steric hindrance, resulting in higher boiling points compared to secondary and tertiary alcohols.
When phenol is treated with Br2 in CCl4 (without water), the product is:
- A. 2-bromophenol only
- B. 2,4-dibromophenol only
- C. 2,4,6-tribromophenol
- D. 4-bromophenol only
Answer: C. 2,4,6-tribromophenol
In CCl4 (aprotic solvent), bromine is more electrophilic and phenol undergoes rapid multiple brominations at all three reactive positions (2, 4, and 6), forming 2,4,6-tribromophenol.
In CCl4 (aprotic solvent), bromine is more electrophilic and phenol undergoes rapid multiple brominations at all three reactive positions (2, 4, and 6), forming 2,4,6-tribromophenol.