Question

which of the following reactions is an acid - base reaction? answer: a agno₃(aq) + kf(aq) → agf(s) + kno₃(aq) b nh₃(aq) + hf(aq) → nh₄⁺(aq) + f⁻(aq) c no₂⁻(aq) + al(s) → nh₃(g) + alo₂⁻(aq) d ch₄(g) + 2o₂(g) → 2h₂o(g) + co₂(g)

Explanation:

An acid - base reaction involves the transfer of a proton ($H^+$). In reaction B, $HF$ (an acid) donates a proton to $NH_3$ (a base) to form $NH_4^+$ and $F^-$. Reaction A is a precipitation reaction, reaction C is a redox reaction, and reaction D is a combustion reaction.

Answer:

B. $NH_3(aq)+HF(aq)
ightarrow NH_4^+(aq) + F^-(aq)$