Question

7) For the chemical reaction NH3(aq) + HCl(aq) → NH- (aq) + CH(aq) the acid and conjugate buse are a) NH3 (acid); NHÀ (Conjugate base) b) NH, (acid), CI (conjugate base) c) HCI (acid); NH; (conjugate base) d) HCI (acid); NHA (conjugate base) e) HCI (acid), CI (conjugate base)

Answer 1

7. This is an application of Bronsted-Lowry Theory of acids and bases.

Bronsted acid-bases only differ by a proton (H⁺).

i) If an acid loses its proton, it becomes conjugate base.

ii) If a base accepts a proton, it becomes conjugate acid.

Coming to the problem,

$NH_3(aq)+HCl(aq)\rightarrow NH_4^+(aq)+Cl^-(aq)$

We know that NH₃ is a base, and HCl is an acid.

So by rule (i), Cl^- is the conjugate base.

By rule (ii), NH₄⁺ is the conjugate acid.

So only the combination in option (e) is correct. HCl (acid), Cl^- (conjugate base).

So option (e) is the correct option.

Hope this helps, thanks!