NCERT MCQ CLASS-12 CHAPTER-11 | CHEMISTRY NCERT MCQ | ALCOHOLS, PHENOLS AND ETHERS | EDUGROWN

In This Post we are  providing Chapter-11 Alcohols, Phenols, and Ethers NCERT MCQ for Class 12 Chemistry which will be beneficial for students. These solutions are updated according to 2021-22 syllabus. These MCQS  can be really helpful in the preparation of Board exams and will provide you with a brief knowledge of the chapter.

NCERT MCQ ON ALCOHOLS, PHENOLS AND ETHERS

Question 1.
Which of the following alcohols gives 2-butenc on dehydration by conc. H₂SO₄?
(a) 2-methyl propene-2-ol
(b) 2-methyl 1 -propanol
(c) Butane-2-ol
(d) Butane 1-ol

Answer: (c) Butane-2-ol

Question 2.
One mole of ethyl acetate on titmen with an excess of LiAlH₄ in dry ether and subsequent acidification produces
(a) 1 mole acetic acid + 1 mole ethyl alcohol
(b) 1 mole ethyl alcohol + 1 mole methyl alcohol
(c) 2 moles of ethyl alcohol
(d) 1 mole of 2-butanol

Answer: (c) 2 moles of ethyl alcohol

Question 3.
Which of the following reagents can not, be used to oxidise primary alcohols to aldehydes?
(a) CrO₃ in anhydrous medium
(b) KMnO₄ in acidic medium
(c) Pyridinium chlorochromate
(d) Heat in the presence of Cu at 573 K

Answer: (b) KMnO₄ in acidic medium

Question 4.
1-Phenylethanol can be prepared by the reaction of benzaldehyde with
(a) methyl bromide
(b) ethyl iodide and magnesium
(c) methyl iodide and magnesium (Grignard reagent’s)
(d) methyl bromide and aluminum bromide

Answer: (c) methyl iodide and magnesium (Grignard reagent’s)

Question 5.
Which of the following alcohols will give the most stable carbocation during dehydration?
(a) 2-methyl-1-propanol
(b) 2-methyl-2-propanol
(c) 1-Butanol
(d) 2-Butanol

Answer: (b) 2-methyl-2-propanol

Question 6.
A compound X with the molecular formula C₂H₈O can be oxidized to another compound Y whose molecular formulae is C₃H₆O₂. The compound X may be
(a) CH₃CH₂OCH₃
(b) CH₃CH₂CHO
(c) CH₃CH₂CH₂OH
(d) CH₃CHOHCH₃

Answer: (c) CH₃CH₂CH₂OH

Question 7.
Order of esterification of alcohols are
(a) 3° > 1° > 2°
(b) 2°> 3° > 1°
(c) 1 ° > 2° > 3°
(d) None of these

Answer: (c) 1 ° > 2° > 3°

Question 8.
What happens when tertiary butyl alcohol is passed over heated copper at 300°C?
(a) Secondary butyl alcohol is formed
(b) 2-methylpropene is formed
(c) 1-butene is formed
(d) Butanol is formed

Answer: (b) 2-methylpropene is formed

Question 9.
Which of the following compounds will be most easily attacked by an electrophile?

Answer: (c)

Question 10.

In the reaction, X is
(a) (CH₃)₂C = CHCH₃
(b) CH₃C = CH
(c) (CH₃)₂CHCH₂CH₃

Answer: (a) (CH₃)₂C = CHCH₃

Question 11.
What would be the reactant and reagent used to obtain 2, 4-dimenthyl pentan-3-ol?
(a) Propanal and propyl magnesium bromide
(b) 3-methylbutanal and 2-methyl magnesium iodide
(c) 2-dimethylpropanone and methyl magnesium iodide
(d) 2-methylpropanal and isopropyl magnesium iodide

Answer: (d) 2-methylpropanal and isopropyl magnesium iodide

Question 12.
The decreasing order of boiling point of the following alcohols is
(a) 3-methylbuan-2-ol > 2-methylbutan-2-ol > pentan-1-ol
(b) Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol
(c) 2-methylbutan-2-ol > 3-methylbutan-2-ol > pentan-1-ol
(d) 2-methylbutan-2-ol > pental-1-ol > 3-methylbutan-2-ol

Answer: (b) Pentan-1-ol > 3-methylbutan-2-ol > 2-methylbutan-2-ol

Question 13.
Acid catalyzed dehydration of t-butanol is faster than that of n-butanol because
(a) tertiary carbocation is more stable than primary carbocation
(b) primary carbocation is more stable than tertiary carbocation
(c) t-butanol has a higher boiling point
(d) rearrangement takes place during dehydration of t- butanol

Answer: (a) tertiary carbocation is more stable than primary carbocation

Question 14.
An unknown alcohol is treated with “Lucas reagent” to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism?
(a) Tertiary alcohol by S_N²
(b) Secondary alcohol by S_N¹
(c) Tertiary alcohol by S_N¹
(d) Secondary alcohol by S_N²

Answer: (c) Tertiary alcohol by S_N¹

Question 15.
An alcohol X when treated with hot cone. H₂SO₄ gave an alkene Y with formula C₄H₈. This alkene on ozonolysis gives single product with molecular formula C₂H₄O. The alcohol is
(a) butan-1-ol,
(b) butan-2-ol
(c) 2-methylpropan-1-ol
(d) 2,2-dimethylbutynal-1-oI

Answer: (b) butan-2-ol

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