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MODEL PAPER 4 — Chemistry STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 ScienceChemistryMODEL PAPER 41 Mark
MCQ
Assertion (A): Aqueous solution of phenol is called as carbonic acid.
Reason (R): Increasing order of acidity of phenols is m nitrophenol >o-nitrophenol >p-nitrophenol.
  • A
    Both A and R are true and R is the correct explanation of A.
  • B
    Both A and R are true but R is not the correct explanation of A.
  • C
    A is true but R is false.
  • ✓
    Both A and R are false.
✓

Answer

Correct option: D.
Both A and R are false.
(d) Both A and R are false.
Explanation:
Aqueous solution of phenol is called carbolic acid. Electron withdrawing groups such as -NO2, -CN, -X- increase the acidity.
The increase is more at o and p - positions than at m-position.
i.e. p-nitrophenol >o-nitrophenol >m-nitrophenol.

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