The strength of an acid depends on its tendency to

Which of the following is a Lewis base?

Which of the following cannot act both as Bronsted acid and as Bronsted base?

Consider the following reaction involving two acids shown below: formic acid and $HF$.
$K^+F^- + HCOOH \rightleftharpoons HCOO^-K^+ + HF$
Given: $pK_a$ of $HCOOH = 3.8$ and $pK_a$ of $HF = 3.2$.
Which of the following statements about this reaction are true?
$(A)$ Formic acid is the strongest Bronsted acid in the reaction
$(B)$ $HF$ is the strongest Bronsted acid in the reaction
$(C)$ $KF$ is the strongest Bronsted base in the reaction
$(D)$ $KO_2CH$ is the strongest Bronsted base in the reaction
$(E)$ The equilibrium favours the reactants
$(F)$ The equilibrium favours the products
$(G)$ Formic acid has a weaker conjugate base
$(H)$ $HF$ has a weaker conjugate base

Give the conjugate acid and conjugate base of the following:
$(i)$ $(CH_3)_2NH$
$(ii)$ $HPO_4^{2-}$
$(iii)$ $HS^{-}$

Which of the following is the correct order of acidity?