Answer:
6 moles
Step-by-step explanation:
Let's consider the unbalanced reaction between phosphoric acid and calcium hydroxide.
H₃PO₄ + Ca(OH)₂ = Ca₃(PO₄)₂ + H₂O
We start by balancing the elements that are just in one compound in each side of the reaction, that is, Ca and P.
2 H₃PO₄ + 3 Ca(OH)₂ = Ca₃(PO₄)₂ + H₂O
Finally, we add moles of water for balancing H and O.
2 H₃PO₄ + 3 Ca(OH)₂ = Ca₃(PO₄)₂ + 6 H₂O
As we can see, 6 moles of water are produced per mole of calcium phosphate.