Explanation:
Relation between [tex]pK_{a}[/tex] and [tex]pK_{b}[/tex] is as follows.
[tex]pK_{a} + pK_{b}[/tex] = 14
Hence, putting the given values of [tex]pK_{a}[/tex] in order to calculate the value of [tex]pK_{b}[/tex] as follows.
For [tex]CH_{3}NH^{+}_{3}[/tex] : [tex]pK_{a} + pK_{b}[/tex] = 14
10.6 + [tex]pK_{b}[/tex] = 14
[tex]pK_{b}[/tex] = 14 - 10.6
= 3.4
For [tex](CH_{3})_{2}NH^{+}_{2}[/tex] : [tex]pK_{a} + pK_{b}[/tex] = 14
10.7 + [tex]pK_{b}[/tex] = 14
[tex]pK_{b}[/tex] = 14 - 10.7
= 3.3
Hence, smaller is the value of [tex]pK_{b}[/tex] of a specie more will be the value of its [tex]K_{b}[/tex]. Therefore, stronger will be the base.
Thus, we can conclude that [tex](CH_{3})_{2}NH^{+}_{2}[/tex] will be the stronger base.
