Question

List the spectator ions (by name) from the reaction of sodium phosphate and copper (II) bromide.

Answer 1

Ans :- Spectator ions are : Sodium ion (Na⁺)  and Bromide ion (Br^-) .

Explanation :-

Spectator ions are those which appear on both the sides in complete ionic equation and are cancel out while writing the net ionic equation.

Balance chemical equation when sodium phosphate and copper (II) bromide reacts with each other.

2 Na₃PO₄ (aq) + 3 CuBr₂ (aq) ----------------> Cu₃ (PO₄)₂ (s) + 6 NaBr (aq)

Complete ionic equation is : Completely dissociate the strong electrolytes while weak electrolytes are partially dissociated.

Cu₃ (PO₄)₂ (s) is insoluble in water thus behave like weak electrolyte.

6 Na⁺ (aq) + 2 PO₄^3- (aq) + 3 Cu²⁺ (aq) + 6 Br^- (aq) ----------------> Cu₃ (PO₄)₂ (s) + 6 Na⁺ (aq) + 6 Br^- (aq)

Net ionic equation is : cancel the spectator ions on both the sides.

2 PO₄^3- (aq) + 3 Cu²⁺ (aq) ----------------> Cu₃ (PO₄)₂ (s)