What is the correct increasing order of extent of deprotonation of the following acids in its aqueous solution?

(I) (CH₃)₂CHCOOH                   (II) CH₃CH₂COOH                (III) Cl₂CHCH₂COOH                (IV) CH₃CCl₂COOH

 

detailed solution

Correct option is A

Electron withdrawing group (Cl) increases acidic strength while electron donating group (CH3) decreases acidic strength.Also magnitude of inductive effect decreases drastically on increasing distance, IV is stronger acid than III. Two methyl groups (in I) gives greater +I effect than one methyl group (in II), hence I is a weaker acid than IITwo -Cl from closer position in IV exert greater -I effect than the same from larger distance in III, hence IV is stronger acid than III.