When aqueous solutions of AgNO_3 and NaCl are mixed, a precipitate forms. What is the chemical formula for the precipitate?

• A. NaCl
• B. AgNO_3
• C. NaNO_3
• D. AgCl

Answer: (D)

Verified step by step guidance

1. Identify the ions present in each aqueous solution. AgNO_3 dissociates into Ag^{+} and NO_3^{-} ions, while NaCl dissociates into Na^{+} and Cl^{-} ions.
2. Determine which ions can combine to form an insoluble compound (precipitate). Use solubility rules: most nitrates (NO_3^{-}) and sodium salts (Na^{+}) are soluble, so they remain in solution.
3. Check the combination of Ag^{+} and Cl^{-} ions. According to solubility rules, silver chloride (AgCl) is insoluble in water and will form a precipitate.
4. Write the chemical formula of the precipitate formed by the combination of Ag^{+} and Cl^{-} ions, which is AgCl.
5. Confirm that the other possible combinations (NaNO_3, AgNO_3, NaCl) remain dissolved in solution and do not form precipitates.