would there still be a visible reaction if we used NaNO3 rather than AgNO3?

Question

Since the indicator is Na2CrO4

Answer 1

When AgNO₃ is added to Cl^-, a white precipitate of AgCl forms. This reaction can be written as:

Molecular equation:

AgNO₃ (aq) + Cl^- (aq) → AgCl (s) + NO₃^- (aq)

Since AgNO₃ is water soluble, it will exist as Ag⁺ and NO₃^- ions in solution. NO₃^- is a spectator ion since it is present on both sides of the equation. Canceling NO₃^- from the equation gives the following net ionic equation.

Ag⁺ (aq) + Cl^- (aq) → AgCl (s)

Similarly, the reaction of chloride ions (Cl^-) in water with NaNO₃ can be written as:

Molecular equation:

NaNO₃ (aq) + Cl^- (aq) → NaCl (aq) + NO₃^- (aq)

Since NaNO₃ and NaCl are water soluble, they will exist only in ionic form in solution. All the ions are spectators, and therefore cancel, resulting in no reaction between NaNO₃ and Cl^-.

Na⁺ (aq) + NO₃^- (aq) + Cl^- (aq) → Na⁺ (aq) + Cl^- (aq) + NO₃^- (aq) ==> NO REACTION

In the 2nd phase of the analysis, the addition of Na₂CrO₄ (a yellow-colored dye) also confirms whether AgNO₃ and/or NaNO₃ reacts with Cl^- in water.

Since we know NaNO₃ + Cl^- gives no reaction, the addition of Na₂CrO₄ will show no change in color to the solution.

However, when Na₂CrO₄ is added to the solution containing AgCl, a red-brown precipitate will form confirming the formation of insoluble Ag₂CrO₄. The molecular and net ionic equations can be written as:

2AgCl (s) + Na₂CrO₄ (aq) → Ag₂CrO₄ (s) + 2NaCl (aq)

2AgCl (s) + CrO₄^2- (aq) → Ag₂CrO₄ (s) + 2Cl^- (aq)