1. Write the balanced chemical equation:

3Ca(OH)₂(aq) + 2H₃PO₄(aq) → Ca₃(PO₄)₂(s) + 6H₂O(l)

2. Determine the mole ratio from the balanced equation:

The balanced equation shows that 3 moles of calcium hydroxide (Ca(OH)₂) react with 2 moles of phosphoric acid (H₃PO₄).

3. Calculate the moles of phosphoric acid:

* Moles = Molarity × Volume (in liters)

* Moles of H₃PO₄ = 0.0215 M × 0.03276 L = 0.000705 moles

4. Calculate the moles of calcium hydroxide needed:

* Use the mole ratio from the balanced equation: (3 moles Ca(OH)₂ / 2 moles H₃PO₄)

* Moles of Ca(OH)₂ = (0.000705 moles H₃PO₄) × (3 moles Ca(OH)₂ / 2 moles H₃PO₄) = 0.0010575 moles Ca(OH)₂

5. Calculate the volume of calcium hydroxide solution:

* Volume = Moles / Molarity

* Volume of Ca(OH)₂ = 0.0010575 moles / 0.03455 M = 0.0306 L

6. Convert the volume to milliliters:

* Volume in mL = 0.0306 L × 1000 mL/L = 30.6 mL

Therefore, you would need 30.6 mL of the 0.03455 M calcium hydroxide solution to completely react with 32.76 mL of the 0.0215 M phosphoric acid solution.