The compound $HCl$ behaves as $...$ in the reaction,$HCl + HF \to H_2Cl^{+} + F^{-}$

Which of the following species are only Lewis acids but not Bronsted acids from $CO_{2}$,$BCl_{3}$,$NH_{3}$,$CH_{3}NH_{2}$,$NO_{2}^{+}$,and $C_{6}H_{5}NH_{3}^{+}$?

Calculate the dissociation constant of a $0.001 \ M$ weak monoacidic base undergoing $2 \%$ dissociation.

Which of the following is the strongest conjugate base?

Which of the following is a Lewis acid?

Which acid among the following has the highest $pK_a$ value?