Answer – Yes, ammonia (NH3) is a base. It is, however, a weak base.
Explanation:
A molecule of ammonia is composed of one nitrogen (N) atom and three hydrogen (H) atoms. Thus, its chemical formula is (NH3). This combination leaves the nitrogen atom with one free pair of electrons.
When dissolved in water, this free pair attracts a hydrogen atom (or proton) from water, and this produces an ammonium ion (NH4+) and a hydroxide ion (OH–).
NH3 (aq) + H2O (l) NH4+ (aq) + OH– (aq)
However, this is a highly reversible reaction. Thus, when in an aqueous solution, instead of dissociating completely into ammonium and hydroxide ions, a large percentage of ammonia molecules remain unchanged. This results in a smaller concentration of hydroxide ions relative to the quantity of ammonia. This incomplete dissociation and low level of hydroxide ions in an aqueous solution means that ammonia is a weak base.
