Answer:
3Ca(OH)2 + 2H3PO4 → Ca3(PO4)2 + 6H2O
Explanation:
This a proper way to balance the equation:
- Count the OH from the base (2)
- Count the H from the acid (3)
We can make 2 molecules of H₂O but we still have one more H
H₃PO₄ → dissociates in → 3H⁺ + PO₄³⁻
Ca(OH)₂ → dissociates in → Ca²⁺ + 2OH⁻
So, to form the salt, you must have 3 Ca²⁺ to react with 2 (PO₄³⁻) to make global charge of +6/-6
Therefore, if you have 3 Ca in the salt, you may have 3 Ca in the base.
So, if you have 2 phosphate in the salt, you must have 2 PO₄³⁻ in the acid.
Now you have 6 protons in the acid (6H) and 6 (OH) in the base; in conclussion you can make 6 H₂O.
Finally the ballance equation is:
3 Ca(OH)₂ + 2 H₃PO₄ → Ca₃(PO₄)₂ + 6H₂O
