The correct answer is a. Ag+ (aq) + Cl- (aq) -> AgCl (s)
Explanation:
When an aqueous solution of sodium chloride (NaCl) is mixed with an aqueous solution of silver nitrate (AgNO3), a double displacement reaction occurs, resulting in the formation of a precipitate of silver chloride (AgCl).
In this reaction, the sodium (Na+) and nitrate (NO3-) ions remain in the aqueous state as spectator ions, while the silver (Ag+) and chloride (Cl-) ions participate in the reaction to form the insoluble silver chloride precipitate.
The balanced net ionic equation represents only the ions that are directly involved in the formation of the precipitate. The spectator ions (Na+ and NO3-) are omitted from the net ionic equation.
Therefore, the balanced net ionic equation for the formation of the silver chloride precipitate is:
Ag+ (aq) + Cl- (aq) → AgCl (s)
The other options are incorrect because:
b. Na+ (aq) + NO3- (aq) -> NaNO3 (s) – This equation represents the formation of solid sodium nitrate, which is not the product of the given reaction.
c. NaCl (aq) + AgNO3 (aq) -> NaNO3 (s) + AgCl (aq) – This equation represents the overall balanced molecular equation, but it does not show the formation of the solid silver chloride precipitate.
d. NaCl (aq) + AgNO3 (aq) -> NaNO3 (aq) + AgCl (s) – This equation is the overall balanced molecular equation, but it does not represent the net ionic equation, which should only include the ions involved in the precipitation reaction.