Question

Draw structures 01 conjugate bases of monochloroacetic acid and dichloroacetic acid. Which one is more stabilized by -I effect?

Answer 1

1. \[\ce{\underset{Acid}{CiC}H2 - COOH + H2O <=> \underset{Conjugate base}{ClCH2 –COO ^–} + H3O^+}\]
   ClCH₂COO ^– is a conjugate base of ClCH₂COOH
2. \[\ce{Cl2CH - COOH + H2O <=> \underset{Conjugate base}{ClCHCOO –} + H3O^+}\]
   ClCHCOO ^– is a conjugate base of Cl₂CHCOOH
3. 
   
   The dichloroacetate ion formed gets stabilised due to electron-withdrawing effect of two chlorine atoms ( – I effect).