To determine which pairs in the given reaction are acid-conjugate base pairs, we need to identify which substances can be considered an acid and its corresponding conjugate base.
Given reaction:
[tex]$NH_4^+ + H_2O \rightarrow NH_3 + H_3O^+$[/tex]
In this reaction, let's analyze each species:
1. [tex]\(NH_4^+\)[/tex] (Ammonium ion): This substance donates a proton ([tex]\(H^+\)[/tex]) to water, indicating that it is acting as an acid.
2. [tex]\(NH_3\)[/tex] (Ammonia): This substance is formed after [tex]\(NH_4^+\)[/tex] donates a proton, meaning it is the conjugate base of [tex]\(NH_4^+\)[/tex].
3. [tex]\(H_2O\)[/tex] (Water): This substance accepts a proton ([tex]\(H^+\)[/tex]) from [tex]\(NH_4^+\)[/tex], meaning it is acting as a base.
4. [tex]\(H_3O^+\)[/tex] (Hydronium ion): This substance is formed when water accepts a proton, meaning it is the conjugate acid of [tex]\(H_2O\)[/tex].
Acid-conjugate base pairs are pairs of compounds that differ by one proton. Once we analyze the reaction, we can pair the substances as follows:
- [tex]\(NH_4^+\)[/tex] (acid) and [tex]\(NH_3\)[/tex] (conjugate base)
- [tex]\(H_2O\)[/tex] (base) and [tex]\(H_3O^+\)[/tex] (conjugate acid)
Now, let's look at the provided options:
1. [tex]\(NH_4^+\)[/tex] and [tex]\(NH_3\)[/tex]
2. [tex]\(NH_4^+\)[/tex] and [tex]\(H_3O^+\)[/tex]
3. [tex]\(H_2O\)[/tex] and [tex]\(NH_3\)[/tex]
4. [tex]\(H_2O\)[/tex] and [tex]\(H_3O^+\)[/tex]
From our analysis:
- [tex]\(NH_4^+\)[/tex] and [tex]\(NH_3\)[/tex] is a correct pair (acid-conjugate base).
- [tex]\(H_2O\)[/tex] and [tex]\(H_3O^+\)[/tex] is another correct pair (base-conjugate acid).
Considering the question asks for an acid-conjugate base pair:
[tex]$\text{The correct answer is: } NH_4^+ \text{ and } NH_3$[/tex]
Therefore, the correct answer is: [tex]$NH_4{ }^{+}$[/tex] and [tex]$NH_3$[/tex].
