The balanced chemical equation given is:
[tex]\[ \text{H}_2\text{SO}_4 + 2 \text{NaOH} \rightarrow 2 \text{H}_2\text{O} + \text{Na}_2\text{SO}_4 \][/tex]
In this equation, we need to identify the acid and its conjugate base.
### Step-by-Step Analysis:
1. Identify the Acid:
- Sulfuric acid ([tex]\(\text{H}_2\text{SO}_4\)[/tex]) donates protons (H^+) in a chemical reaction and is therefore an acid.
2. Identify What the Acid Turns Into After the Reaction:
- When sulfuric acid ([tex]\(\text{H}_2\text{SO}_4\)[/tex]) dissociates, it produces [tex]\( \text{HSO}_4^- \)[/tex] and [tex]\( \text{SO}_4^{2-} \)[/tex]; in the reaction, it’s completely dissociated into [tex]\( \text{SO}_4^{2-} \)[/tex].
- In the product side of the reaction, [tex]\( \text{SO}_4^{2-} \)[/tex] is found in the compound [tex]\( \text{Na}_2\text{SO}_4 \)[/tex].
3. Determine the Conjugate Base:
- The conjugate base of an acid is what is left after the acid has donated a proton (H^+).
- For [tex]\(\text{H}_2\text{SO}_4\)[/tex], the conjugate base is [tex]\(\text{SO}_4^{2-}\)[/tex].
- In the product, [tex]\(\text{SO}_4^{2-}\)[/tex] is part of [tex]\(\text{Na}_2\text{SO}_4\)[/tex].
4. Match Acid and Conjugate Base to Given Answer Choices:
- [tex]\(\text{H}_2\text{SO}_4 / \text{H}_2\text{O}\)[/tex]: [tex]\( \text{H}_2\text{O} \)[/tex] is not related to [tex]\(\text{H}_2\text{SO}_4\)[/tex] as a conjugate base.
- [tex]\(\text{H}_2\text{SO}_4 / \text{Na}_2\text{SO}_4\)[/tex]: Correct match. [tex]\(\text{Na}_2\text{SO}_4\)[/tex] contains the conjugate base of [tex]\(\text{H}_2\text{SO}_4\)[/tex], which is [tex]\(\text{SO}_4^{2-}\)[/tex].
- [tex]\(\text{NaOH} / \text{H}_2\text{O}\)[/tex]: [tex]\( \text{NaOH} \)[/tex] is a base and [tex]\( \text{H}_2\text{O} \)[/tex] is neutral.
- [tex]\(\text{NaOH} / \text{Na}_2\text{SO}_4\)[/tex]: [tex]\(\text{NaOH}\)[/tex] is a base and does not have [tex]\(\text{Na}_2\text{SO}_4\)[/tex] as its conjugate acid/base pair.
### Conclusion:
The correct acid-conjugate base pair in the given balanced equation is:
[tex]\[ \text{H}_2\text{SO}_4 / \text{Na}_2\text{SO}_4 \][/tex]
So, the correct answer is:
[tex]\[\boxed{\text{H}_2\text{SO}_4 / \text{Na}_2\text{SO}_4}\][/tex]
