Sign in
12thPass logo
New chatPYQ LibraryDoubtsRank report
Sign in to see Recents

Your guest activity stays on this device

Sign in to save progress →
Sign in

Alcohols Phenols and Ethers question

2024 · 31 Jan · Shift 1 · Q8
Guest · filters and generic practice availableBrowsing as a guest · PYQ filters and generic practice are available. Sign in only for personalised features and saved progress.
  1. PYQ Library
  2. /JEE Main
  3. /Chemistry
  4. /Alcohols Phenols and Ethers
  5. /2024 · 31 Jan · Shift 1 · Q8

Alcohols Phenols and Ethers question

2024 · 31 Jan · Shift 1 · Q8

JEE MainChemistryAlcohols Phenols and EthersMCQ+4 / −1
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R: Assertion A: Alcohols react both as nucleophiles and electrophiles. Reason R: Alcohols react with active metals such as sodium, potassium and aluminum to yield corresponding alkoxides and liberate hydrogen. In the light of the above statements, choose the correct answer from the options given below:
  1. A
    AAA is false but RRR is true.
  2. B
    Both AAA and RRR are true but RRR is NOT the correct explanation of AAA.
  3. C
    Both AAA and RRR are true and RRR is the correct explanation of AAA.
  4. D
    AAA is true but RRR is false.
View written solutionFree

Correct answer: B

  1. Check Assertion A: Alcohols react both as nucleophiles and electrophiles.

    This statement is true.

    • As nucleophiles: Alcohols contain lone pairs on oxygen, so they can donate an electron pair. R−OH  acts as a nucleophileR-OH \; \text{acts as a nucleophile}R−OHacts as a nucleophile
    • As electrophiles: In reactions where the C−OC-OC−O bond is attacked, the carbon attached to OHOHOH can behave as an electrophilic center, especially after protonation of the alcohol. For example: R−OH+H+→R−OH2+R-OH + H^+ \rightarrow R-OH_2^+R−OH+H+→R−OH2+​ Now water is a good leaving group, and the carbon can be attacked by nucleophiles.

    Hence, Assertion A is true.

  2. Check Reason R: Alcohols react with active metals such as sodium, potassium and aluminum to yield corresponding alkoxides and liberate hydrogen.

    This statement is also true.

    Example: 2R−OH+2Na→2R−ONa+H22R-OH + 2Na \rightarrow 2R-ONa + H_22R−OH+2Na→2R−ONa+H2​

    This shows the acidic character of alcohols due to the polar O−HO-HO−H bond.

  3. Does R correctly explain A?

    No.

    • Assertion A is about alcohols behaving as nucleophiles and electrophiles.
    • Reason R discusses reaction with active metals, which demonstrates the acidic nature of alcohols, not their dual nucleophilic/electrophilic behavior.

    Therefore, R is true, but it is not the correct explanation of A.

  4. Correct option: B\boxed{B}B​

  5. Comparison with stored correct answer:

    Stored correct answer = B

    My derived answer = B

    So, they agree.

PreviousNext

More from Alcohols Phenols and Ethers

  • Identify the incorrect option from the following2023 · MCQ
  • Decreasing order of dehydration of the following alcohols is Includes diagram2023 · MCQ
  • The graph which represents the following reaction is : Includes diagram2023 · MCQ
  • The strongest acid from the following is2023 · MCQ
  • Among the following, the number of compounds which will give positive iodoform reaction is ​ (a) 1-Phenylbutan-2-one (b) 2-Methylbutan-2-ol (c) 3-Methylbutan-2-ol (d) 1-Phenylethanol (e) 3,3-dimethylbutan-2-one (f)…2023 · Numerical
  • Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Butan -1- ol has higher boiling point than ethoxyethane. Reason R: Extensive hydrogen bonding leads to stronger association…2023 · MCQ
  • The water gas on reacting with cobalt as a catalyst forms2023 · MCQ
  • Suitable reaction condition for preparation of Methyl phenyl ether is2023 · MCQ