To identify the acid-conjugate base pair in the given reaction:
[tex]$
HI + H_2O \rightarrow H_3O^+ + I^-
$[/tex]
we need to determine which species donates and accepts protons (H⁺).
1. An acid is a species that donates a proton.
2. A base is a species that accepts a proton.
3. The conjugate base is what remains after the acid donates its proton.
4. The conjugate acid is what is formed when the base accepts a proton.
Let's analyze each component of the reaction:
1. HI:
- HI donates a proton (H⁺) to become I⁻.
- In this case, HI is the acid because it donates a proton.
- I⁻ is the conjugate base, as it is what remains after HI donates the proton.
2. H₂O:
- H₂O accepts a proton to become H₃O⁺.
- H₂O is acting as a base here because it accepts a proton.
- H₃O⁺ is the conjugate acid as it is formed when H₂O accepts the proton.
Now, we look at the pairs:
- HI and I⁻ form an acid-conjugate base pair.
- H₂O and H₃O⁺ form another pair, but this is not in the list of options.
The correct acid-conjugate base pair from the given options is:
HI and I⁻