Which one is not an acid salt?

For the following two acid-base reactions,which statement is True?
$(I) CH_3CH_2^- + CH_3NH_2$ $(pK_a = 35)$ $\rightleftharpoons CH_3CH_3$ $(pK_a = 50)$ $+ CH_3NH^-$
$(II) F^- + H_2O$ $(pK_a = 15.7)$ $\rightleftharpoons HF$ $(pK_a = 3.2)$ $+ HO^-$

Which of the following salts is acidic?

Which of the following is not a conjugate acid-base pair?

Identify the conjugate acid-base pair in the following reaction.
$H_2O + HCl \rightarrow H_3O^{+} + Cl^{-}$

When $KHSO_4$ is added into a concentrated solution of $H_2SO_4$,the acidity of the solution