Answer: It combines with H+ions.
Explanation: It combines with H+ions.
Ammonia releases [tex]OH^-[/tex] ions.
According to Arrhenius concept, a base is defined as a substance which donates hydroxide ions [tex](OH^-)[/tex] when dissolved in water and an acid is defined as a substance which donates hydronium ions [tex](H_3O^+)[/tex] in water.
According to the Bronsted Lowry conjugate acid-base theory, an acid is defined as a substance which donates protons and a base is defined as a substance which accepts protons.
According to the Lewis concept, an acid is defined as a substance that accepts electron pairs and base is defined as a substance which donates electron pairs.
[tex]NH_3+H^+\rightarrow NH_4^+[/tex]
[tex]NH_4OH(aq)\rightarrow NH_4^++OH^-[/tex]
Ammonia being a lewis base donates lone pair of electrons and thus combines with [tex]H^+[/tex]. Also aqueous solution of ammonia gives [tex]OH^-[/tex] ions in water, thus act as Arrhenius base.
