$NH_4OH$ is a weak base because

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

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 base.

What is the conjugate base of $OH^{-}$?

$A$ solution of ammonia in water contains

Which of the following is not a Lewis base?