Question

which compound is not a base? a nh₃ b naoh c hclo₄ d nh₄oh

Explanation:

• A base is a substance that accepts protons (Bronsted - Lowry) or donates hydroxide ions (Arrhenius) or donates electron pairs (Lewis).
• \(NH_3\) is a Lewis base (donates electron pair), \(NaOH\) is an Arrhenius base (\(NaOH

ightarrow Na^++OH^-\)), \(NH_4OH\) (or \(NH_3\cdot H_2O\)) is a base (\(NH_3\cdot H_2O
ightleftharpoons NH_4^++OH^-\)).

• \(HClO_4\) is perchloric acid, it donates \(H^+\) ions (\(HClO_4

ightarrow H^++ClO_4^-\)), so it is an acid, not a base.

Answer:

C. \(HClO_4\)