Question

The $p{K}_a$ values of four carboxylic acids are $4.76,4.19,0.23$ and $3.41$ respectively. The $p{K}_a$ value of strongest carboxylic acid among them is:

• A. $4.19$
• B. $3.41$
• C. $0.23$
• D. $4.76$

Answer 1

Answer: (C)

$0.23$

$K_a$ values is directly proportional to the strength of acid.
Whereas :
$p{K}_a$ value is inversely proportional to the strength of acid.
Means more the $K_a$ value, more will be acidic strength , whereas :
Lesser the $p{K}_a$ values , more the acidic strength.
Hence strongest acid is for the , $p{K}_a=0.23$ and weakest acid is for the $p{K}_a=4.76$.