Question

Which acid exhibits the lowest value for its pKa?
a) Acetic acid
b) 2- chlorobutanoic acid
c) 3- chlorobutanoic acid
d) tri-chloro acetic acid​

Answer 1

Option “A” is correct i.e. CH3COOH (Acetic acid)

• Among the given acids, the acetic acid has the lowest pKa value because of the reason that when R increases, then the pKa value also increases.

• The pKa value is one technique used to specify the strength of an acid. pKa is mainly defined as the negative log of the Ka value or the acid dissociation constant. A lower pKa value designates a stronger acid.  

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