To solve this problem and identify the conjugate acid-base pairs, let's break down the given chemical reaction:
[tex]\[
H_3PO_4 + H_2O \rightleftharpoons H_2PO_4^- + H_3O^+
\][/tex]
We'll start by identifying which substances are acids and which are bases in this reaction. Recall that an acid is a substance that donates a proton (H⁺), and a base is a substance that accepts a proton.
### Step-by-Step Solution
1. Identifying the Acid and Conjugate Base Pair:
- Acid: Phosphoric acid ([tex]\(H_3PO_4\)[/tex]) is donating a proton to become dihydrogen phosphate ion ([tex]\(H_2PO_4^-\)[/tex]). Therefore, [tex]\(H_3PO_4\)[/tex] is the acid.
- Conjugate Base: After donating a proton, [tex]\(H_3PO_4\)[/tex] becomes [tex]\(H_2PO_4^-\)[/tex], which is the conjugate base of [tex]\(H_3PO_4\)[/tex].
2. Identifying the Base and Conjugate Acid Pair:
- Base: Water ([tex]\(H_2O\)[/tex]) is accepting a proton to become the hydronium ion ([tex]\(H_3O^+\)[/tex]). Thus, [tex]\(H_2O\)[/tex] is the base.
- Conjugate Acid: After accepting a proton, [tex]\(H_2O\)[/tex] becomes [tex]\(H_3O^+\)[/tex], which is the conjugate acid of [tex]\(H_2O\)[/tex].
Using this information, we can now categorize each substance appropriately:
- Acid (donates a proton):
- [tex]\(H_3PO_4\)[/tex]
- Conjugate Base (what the acid becomes after donating a proton):
- [tex]\(H_2PO_4^-\)[/tex]
- Base (accepts a proton):
- [tex]\(H_2O\)[/tex]
- Conjugate Acid (what the base becomes after accepting a proton):
- [tex]\(H_3O^+\)[/tex]
### Summary of Bins
1. Acid:
- [tex]\(H_3PO_4\)[/tex]
2. Conjugate Base:
- [tex]\(H_2PO_4^-\)[/tex]
3. Base:
- [tex]\(H_2O\)[/tex]
4. Conjugate Acid:
- [tex]\(H_3O^+\)[/tex]
Thus, we have correctly identified the acid-base pairs in the chemical reaction.
