Among the following,the dissociation constant $(K_a)$ is highest for:

The value of enthalpy of neutralization is the lowest for the reaction between:

The compound that is not a Lewis acid is

The conjugate bases for $HCO_3^-$ and $NH_3$,respectively,are

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