# Question c3d97

May 9, 2016

Ammonia is a compound , but the word "ammonium" relates only to the positive ion ($N {H}_{4}^{+}$)
Ammonia relates to the compound $N {H}_{3}$, whether it is in the gaseous state, or liquefied - but we're talking about the pure substance $N {H}_{3}$ here, not a solution or mixture with anything else.
When ammonia is mixed with water, however, it deprotonates the water to a small extent, forming the ions $N {H}_{4}^{+}$+ and $O {H}^{-}$ as follows: NH_3 + H_2O ⇌ NH_4^+ + OH^−#
$N {H}_{4}^{+}$ ions are known as " ammonium ions ", so the solution of ammonia in water (commonly called "household ammonia" or "ammonia solution") should really be referred to as " ammonium hydroxide ".