Question

The increasing order of $p{K}_a$ values for the following carboxylic acids is
(1) Acetic acid
(2) Formic acid
(3) Benzoic acid
(4) Trichloroacetic acid

• A. $(4)<(2)<(3)<(1)$
• B. $(3)<(1)<(2)<(4)$
• C. $(2)<(4)<(3)<(1)$
• D. $(3)<(1)<(4)<(2)$

Answer 1

Answer: (A)

The order of acidic strength is :
Trichloroacetic acid $>$ formic acid $>$ benzoic acid $>$ acetic acid
Hence, the increasing order of $pKa$ values is:
Trichloroacetic acid $<$ formic acid $<$ benzoic acid $<$ acetic acid