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7. Alcohol, phenol and ethers — Chemistry STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 ScienceChemistry7. Alcohol, phenol and ethers1 Mark
MCQ
Given below are two statements: One is labelled as $A$ssertion $A$ and the other is labelled as $R$eason $R$:

Assertion $A$: $\mathrm{pK}_{\mathrm{a}}$ value of phenol is $10.0$ while that of ethanol is $15.9$.

Reason $R$: Ethanol is stronger acid than phenol.In the light of the above statements, choose the correct answer from the options given below:

  • ✓
    $A$ is true but $R$ is false.
  • B
    A is false but $R$ is true.
  • C
     Both $A$ and $R$ are true and $R$ is the correct explanation of $A$.
  • D
    Both $A$ and $R$ are true but $R$ is $NOT$ the correct explanation of $A$.
✓

Answer

Correct option: A.
$A$ is true but $R$ is false.
a
Phenol is more acidic than ethanol because conjugate base of phenoxide is more stable than ethoxide.

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