1. Write the complete balanced molecular equation:
3Ca(OH)₂(aq) + 2H₃PO₄(aq) → Ca₃(PO₄)₂(s) + 6H₂O(l)
2. Identify the soluble ionic compounds:
* Calcium hydroxide (Ca(OH)₂) is slightly soluble, but we'll treat it as soluble for this reaction.
* Phosphoric acid (H₃PO₄) is soluble.
* Calcium phosphate (Ca₃(PO₄)₂) is insoluble.
* Water (H₂O) is a liquid.
3. Write the complete ionic equation:
3Ca²⁺(aq) + 6OH⁻(aq) + 6H⁺(aq) + 2PO₄³⁻(aq) → Ca₃(PO₄)₂(s) + 6H₂O(l)
4. Identify and cancel spectator ions:
* Spectator ions are present on both sides of the equation and do not participate in the reaction. In this case, there are no spectator ions.
5. Write the net ionic equation:
3Ca²⁺(aq) + 6OH⁻(aq) + 6H⁺(aq) + 2PO₄³⁻(aq) → Ca₃(PO₄)₂(s) + 6H₂O(l)
Therefore, the balanced net ionic equation for the reaction of aqueous calcium hydroxide with phosphoric acid is:
3Ca²⁺(aq) + 6OH⁻(aq) + 6H⁺(aq) + 2PO₄³⁻(aq) → Ca₃(PO₄)₂(s) + 6H₂O(l)
