Answer: Option (b) is the correct answer.
Explanation:
Relation between [tex]K_{a}[/tex] and [tex]pK_{a}[/tex] is as follows.
[tex]pK_{a} = -log K_{a}[/tex]
where, [tex]K_{a}[/tex] is the acid dissociation constant.
As value of [tex]K_{a}[/tex] is given as [tex]10^{-11}[/tex]. Therefore, calculating teh value of [tex]pK_{a}[/tex] as follows.
[tex]pK_{a} = -log K_{a}[/tex]
= -log ([tex]10^{-11}[/tex])
= - (-11 × log (10))
= 11
Thus, we can conclude that the [tex]pK_{a}[/tex] of an acid whose [tex]K_{a} = 10^{-11}[/tex] is 11.
