Choose the correct net ionic equation for the reaction in water of CaCl₂ and Na₃PO₄.

Question

Quizplus · Accepted Answer

The two soluble salts (CaCl2 and Na2S) will dissociate into their respective ions. The Ca2+ and S2- ions will combine to form an insoluble precipitate of CaS. The net ionic equation is:

3 Ca2+ (aq) + 2 S2- (aq) + 2 Na+ (aq) + 2 PO43- (aq) → Ca3(PO4)2 (s) + 2 Na+ (aq) + 6 Cl- (aq)

After simplification, we get:

3 Ca2+ (aq) + 2 S2- (aq) + 2 Na+ (aq) + 2 PO43- (aq) → CaS (s) + 2 Na+ (aq) + 6 Cl- (aq)

This matches choice C.

Choose the Correct Net Ionic Equation for the Reaction in Water