The balanced chemical equation for the reaction between aqueous phosphate (PO43-) and aqueous zinc ions (Zn²+) to form solid zinc phosphate (Zn3(PO4)2) is:
3 PO43- (aq) + 2 Zn²+ (aq) → Zn3(PO4)2 (s)
This balanced equation shows that three moles of phosphate ions react with two moles of zinc ions to produce one mole of solid zinc phosphate.