What do you understand by conjugate pairs of acid and base? Sort out the conjugate pairs in the following reactions.
`NH_4 ^(+) (aq) +S^(2-) (aq) hArr HS^(-) (aq) + NH_3 (aq)`

Explanation

To understand conjugate pairs of acids and bases, we need to recognize that they are pairs of compounds that differ by a single proton (H⁺). In the context of acid-base reactions, when an acid donates a proton, it forms its conjugate base, and when a base accepts a proton, it forms its conjugate acid.

Let's analyze the given reaction step by step:

**Given Reaction:**
\[ \text{NH}_4^+ (aq) + \text{S}^{2-} (aq) \rightleftharpoons \text{HS}^- (aq) + \text{NH}_3 (aq) \]

### Step 1: Identify the Acid and Base
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