The correct order of decreasing acid strength of trichloroacetic acid $(A)$, trifluoroacetic acid $(B)$, acetic acid $(C)$ and formic acid $(D)$ is

• Correct answer
  A

  $B>A>D>C$
• B

  $B>D>C>A$
• C

  $A>B>C>D$
• D

  $A>C>B>D$

Solution

If an electron withdrawing group ( $-I$ showing group) is present, it makes the removal of proton more easy by stabilising the remaining carboxylate ion and thus, makes the acid more acidic. The order of acidity of given compounds is

Hence, the correct answer is option: 'A'.