Practise 22 real Federal Board questions on Alcohols/Phenols/Ethers from 2023 to 2026. See the answer and explanation as soon as you answer.
Alcohols/Phenols/Ethers is one of the 19 main chapters in our Federal Board FSC Chemistry question bank (11th and 12th class), and about 4% of its real questions come from it. Tayyari Karo has 22 real questions on this chapter from 2023 to 2026; 4 are multiple choice and marked instantly, and the rest are short and long questions with a model answer. By difficulty: 15 medium, 6 hard, 1 easy.
Work through the questions below, then open the explanation for each one. Redo the ones you missed a few days later.
These are real past-paper questions. Think of your answer first, then open the explanation.
Which alcohol will yield an oily layer immediately on heating, according to Lucas test?
Answer: A. 2-Methyl-2-Propanol
Tertiary alcohols react fastest with Lucas reagent (immediate turbidity/oily layer, even in the cold) via the stable SN1 carbocation pathway.
Which compound shows Hydrogen Bonding?
Answer: A. C₂H₅OH
Ethanol (C₂H₅OH) has an O-H group capable of hydrogen bonding; the others lack an N-H/O-H/F-H bond.
Phenol can be prepared from benzene sulfonic acid by:
Answer: C. Fusion with NaOH
Benzene sulfonic acid, when fused with NaOH (alkali fusion), converts to sodium phenoxide, which on acidification gives phenol.
Ethers show the phenomenon of:
Answer: C. Metamerism
Ethers of the same molecular formula but different alkyl groups on either side of the oxygen (e.g. diethyl ether vs methyl propyl ether) show metamerism.
Determine whether the following compound is optically active: CH₃-CH(OH)-Br. Justify your answer.
The central carbon in CH₃-CH(OH)-Br is attached to four different groups: -CH₃, -OH, -Br, and -H. Since all four substituents are different, this carbon is a chiral center, and the molecule (lacking any internal symmetry/plane of symmetry) is therefore optically active.
Write down the reactions of 1-Propanol with: a) SOCl₂ b) PCl₅ c) Conc. H₂SO₄/180°
a. CH₃CH₂CH₂OH + SOCl₂ → CH₃CH₂CH₂Cl + SO₂↑ + HCl↑
b. CH₃CH₂CH₂OH + PCl₅ → CH₃CH₂CH₂Cl + POCl₃ + HCl
c. CH₃CH₂CH₂OH --conc. H₂SO₄, 180°C--> CH₃CH=CH₂ (propene) + H₂O
Why phenol is more acidic than alcohol? Explain briefly.
When phenol loses a proton, the resulting phenoxide ion (C₆H₅O⁻) can delocalize its negative charge into the aromatic ring by resonance, spreading the charge over several ring carbons and stabilizing the ion. An alcohol's alkoxide ion (RO⁻) has no such resonance delocalization — the negative charge stays localized on oxygen, making it far less stable. Because the phenoxide ion is more stable, phenol dissociates more readily and is more acidic than an alcohol.
How can Dimethyl ether be prepared by: a. Williamson's synthesis b. From an alkyl halide
a. Williamson's synthesis: CH₃O⁻Na⁺ (sodium methoxide) + CH₃Br (methyl bromide) → CH₃-O-CH₃ + NaBr (SN2 reaction between an alkoxide and an alkyl halide).
b. From an alkyl halide (dry Ag₂O method): 2CH₃Br + Ag₂O → CH₃-O-CH₃ + 2AgBr
| Session | Questions |
|---|---|
| 2026 Annual | 2 |
| 2025 1st Annual | 8 |
| 2025 2nd Annual | 4 |
| 2024 Annual | 5 |
| 2023 Annual | 3 |
22 real Federal Board (FBISE) Chemistry questions on Alcohols/Phenols/Ethers from 2023 to 2026, for 11th and 12th class. Each one shows the session it came from.
No. We could not find an official FBISE marking scheme for these papers, so the answers and explanations are written by Tayyari Karo for practice. Check anything important with your teacher or textbook.
You can start free with no signup. A small set of papers per subject is free, and Premium unlocks the full question bank.
