# Identifying nucleophiles and electrophiles in an acid-base reaction

Is ammonia a nucleophile and hydrogen the electrophile in the Brønsted-Lowry acid-base reaction of acetic acid with ammonia? $$\ce{CH3COOH + NH3 <=> CH3COO- + NH4+}$$

I say that ammonia is the nucleophile because I drew a curved arrow from the lone pair on the ammonia to the ionizable hydrogen on acetic acid, and I drew a curved arrow from the bonding pair in the hydroxyl group to the oxygen in the hydroxyl group of acetic acid. It seems that ammonia is the nucleophile because it is attacking the hydrogen proton (a bare proton) and that hydrogen is the electrophile because it likes the lone pair on ammonia.

So if the above is right, this would make ammonia a Lewis base and the hydrogen proton a Lewis acid? Or do we say the entire acetic acid molecule is a Lewis acid?

$$\ce{\underset{Lewis acid}{Me3B} + \underset{Lewis base}{:\!NH_\phantom{3}} -> \underset{Lewis adduct}{Me3\overset{-}{B}-\overset{+}{N}H3}}$$