Precipitation of Silver Chloride
When clear, colorless silver nitrate solution is added to clear, colorless sodium chloride solution, white silver chloride precipitates.
This demo is typically performed when solubility rules are being presented. Allow two minutes for this demo.
Almost all alkali metal compounds and nitrates are soluble, but most silver compounds are insoluble (except for acetates, perchlorates, chlorates, and nitrates). Therefore, when the soluble salts silver nitrate and sodium chloride are mixed, insoluble silver chloride forms and precipitates out. (Ksp = 1.77 x 10-10)1 AgNO3(aq) + NaCl(aq) --> AgCl(s) + NaNO3(aq) or Ag+(aq) + Cl-(aq) --> AgCl(s) Silver nitrate is used in photography, medicine, silver plating and refining, and in making mirrors and indelible ink.2
1 James C. Chang. "Solubility Product Constants." Handbook of Chemistry and Physics. Weast, Robert C., ed. 67th ed. Boca Raton, FL: CRC Press, Inc., 1986. p.B208. 2The Chemistry Hall of Fame
- about 500mL 1M sodium chloride solution
- dropper bottle of 0.1M silver nitrate solution
- glass cylinder
- background box
Place the glass cylinder in front of the background box to provide better visibility. The black background works best for this demo. Fill the cylinder about halfway with sodium chloride solution. Add several droppers full of silver nitrate solution to the cylinder. Immediately a white precipitate forms.
Silver nitrate is a strong oxidizer, but the solution is fairly dilute. Wear goggles. Avoid getting silver nitrate solution on your skin. If your skin comes into contact with silver nitrate solution, immediately wash thoroughly with soap and water. If you get silver nitrate solution in your eyes, flush with water for 15 minutes and seek medical help. (But don't worry too much, this solution is about 1.5% by weight and 1% solution is used to treat eye infections.)
