Which of the following fertilizers increases the acidity of the soil upon regular use?

The conjugate acid of $HS^{-}$ is

$BF_3$ acts as an acid according to .............

The species: $H_{2}O$,$HCO_{3}^{-}$,$HSO_{4}^{-}$,and $NH_{3}$ can act both as Bronsted acids and bases. For each case,give the corresponding conjugate acid and conjugate base.

Which of the following is not a Lewis acid?

When $HClO_4$ is dissolved in the weak acid $HF$,the following equilibrium is established:
$HF + HClO_4 \rightleftharpoons H_2F^+ + ClO_4^-$
Which of the following is the correct set of conjugate acid-base pairs?