Given below are two statements : Statement (I) : p-nitrophenol is more acidic than m-nitrophenol and…

Given below are two statements :

Statement (I) : p-nitrophenol is more acidic than m-nitrophenol and o-nitrophenol.

Statement (II) : Ethanol will give immediate turbidity with Lucas reagent.

In the light of the above statements, choose the correct answer from the options given below :

  1. Statement I is true but Statement II is false
  2. Both Statement I and Statement II are true
  3. Both Statement I and Statement II are false
  4. Statement I is false but Statement II is true

Solution

p-Nitrophenol is more acidic than m-nitrophenol and o-nitrophenol.
The electron withdrawing group -NO2 stabilizes phenoxide ion through -R effect at para and ortho
position.
-NO2 group in meta position will show -I effect.
Presence of -NO2 group at ortho position it form hydrogen bonding with -OH group. Hence, acidity is less than p-nitrophenol order of acidic strength.

Acidic strength

Ethanol give lucas test after long time

Lucas reagent helps in the distinction of primary, secondary and tertiary alcohols. A small quantity of unknown alcohol is added to Lucas reagent (anhyd. ZnCl2 + conc. HCl) at room temperature and the mixture is shaken. A tertiary alcohol forms turbidity immediately, secondary alcohol forms turbidity within five minutes and primary alcohol shows no turbidity at room temperature.

So, Statement I is correct, but Statement II is incorrect.

Asked in: JEE Main 2024 (27 Jan Shift 1)

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