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JEE Advanced levelOne or more correct optionsDifficulty 3 of 3g2108

An ether solution contains aniline, benzoic acid (pKa 4.20), phenol (pKa 10.0) and toluene. Using pKaH of anilinium 4.6 and pKa of 6.4, which statements about extraction with aqueous solutions are correct?

  1. ADilute HCl extracts aniline into the aqueous layer as anilinium chloride
  2. BAqueous extracts benzoic acid but not phenol
  3. CAqueous (after the earlier extractions) can extract phenol
  4. DAqueous extracts phenol as well as benzoic acid

Answer: A, B, C

Aniline is basic enough to be protonated by dilute HCl. Bicarbonate (conjugate acid pKa 6.4) deprotonates benzoic acid (4.20) but not phenol (10.0). Hydroxide (15.7) deprotonates phenol. D is false, and toluene remains in the ether.
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