Answer – In a chemical reaction, spectator ions are ions that do not participate in the overall chemical change.
Explanation:
Spectator ions remain unchanged on both sides of the equation, hence the name “spectator”. They do not contribute to the formation of products or the consumption of reactants. They are typically found in ionic compounds dissolved in a solution.
In the reaction of aqueous solutions of sodium chloride (NaCl) and copper (II) sulfate (CuSO4), the sodium (Na+) and sulfate (SO4−2) ions are spectator ions.
NaCl dissociates into Na⁺ ions and Cl⁻ ions: Na⁺ (aq) + Cl⁻ (aq)
CuSO₄ dissociates into Cu²⁺ ions and SO₄²⁻ ions: Cu²⁺ (aq) + SO₄²⁻ (aq)
The ionic form of this reaction is: 2 Na+ (aq) + 2 Cl– (aq) + Cu2+ (aq) + SO42- (aq) → 2 Na+ (aq) + SO42- (aq) + CuCl2 (s).
Copper ions (Cu²⁺) from CuSO₄ combine with chloride ions (Cl⁻) from NaCl to form solid copper (II) chloride (CuCl₂). After the reaction, the solution contains the spectator ions Na⁺ and SO₄²⁻.
