In the reaction: `[Cu(H_(2)O)_(3)(OH)]^(+) + [AI(H_(2)O)_(6)]^(3+) to [Cu(H_(2)O)_(4)]^(2+) + [AI(H_(2)O)_(5)(OH)]^(2+)`

Options

A. C is the conjugate acid of A and D is the conjugate base of B
B. A is an acid and B is the base
C. A is a base and B is the salt
D. C is the conjugate base of A and D is the conjugate acid of B

Answer

To analyze the given reaction and determine the roles of the species involved, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- Reactants: \([Cu(H_2O)_3(OH)]^+\) (let's call this A) and \([Al(H_2O)_6]^{3+}\) (let's call this B).
- Products: \([Cu(H_2O)_4]^{2+}\) (let's call this C) and \([Al(H_2O)_5(OH)]^{2+}\) (let's call this D).

2. **Determine Acid-Base Roles**:
- In this reaction, A (the copper complex) acts as a base because it accepts a proton (H⁺) from B (the aluminum complex).
- B acts as an acid because it donates a proton (H⁺) to A.

3. **Identify Conjugate Acid and Base**:
- After A accepts a proton, it transforms into C. Therefore, C is the conjugate acid of A.
- After B donates a proton, it transforms into D. Therefore, D is the conjugate base of B.

4. **Summarize the Acid-Base Pairs**:
- A (base) → C (conjugate acid)
- B (acid) → D (conjugate base)

5. **Evaluate the Options**:
- Option 1: A is a base, B is an acid (Correct).
- Option 2: A is an acid, B is a base (Incorrect).
- Option 3: A is a base, B is a salt (Incorrect).
- Option 4: C is the conjugate base of A and D is the conjugate acid of B (Incorrect).

6. **Conclusion**:
- The correct option is that A is a base and B is an acid, making option 1 the right answer.