KCET2018ChemistryAlcohols Phenols and Ethers
What is the increasing order of acidic strength among the following? (i) p-methoxy phenol (ii) p-methyl phenol (iii) p-nitro phenol
Options
- A( ii < iii < i )
- B( iii < ii < i )
- C( i < ii < iii )
- D( i < iii < i )
Correct answer
C. ( i < ii < iii )
Step-by-step solution
Presence of ( - NO ₂ ) group increases the acidic character of phenol, because it is an electron withdrawing group, it withdraws the electron towards itself thereby decreasing the ( e⁻ )density on the conjugate base so formed and stabilizes by resonance, whereas the electron releasing groups increases the ( e⁻ )density on conjugate base and destabilizes it. Therefore, the increasing order of acidic strength is : ( | < | < ||| ).