Silvering Glass

Create Silver-Mirrored Christmas Ornaments with a Redox Reaction

Create silver ornaments with your students using a chemical process similar to antique mirroring techniques. In this festive activity, silver is plated onto the interior surface of a glass vial via a redox reaction. In the reaction, dextrose is oxidized to gluconic acid, and silver ions are reduced to metallic silver.

Topics covered: redox reactions, Lewis acids and bases, organic structures, complexes, and stoichiometry.

Materials

• Acetone
• 0.5 M Silver Nitrate
• 1.5 M Ammonium Nitrate (prepare fresh for each demo)
• 5% Dextrose Solution
• 3 M Sodium Hydroxide
• Sodium Chloride (for waste)
• Disposable Pipets
• Glass Vials, 2 dram
• Beaker, 600 mL
• Glass Stir Rod
• Deionized Water
• Tap Water
• Curling ribbon (optional)
• Ornament hangers or paper clips (optional)

Safety

• Keep acetone away from heat, sparks, and flame.
• Keep ammonium nitrate away from clothing and other combustible materials.
• Sodium hydroxide causes skin and eye burns; avoid contact with skin, eyes, and clothing.
• The waste products from this activity can form explosive silver compounds. After the demonstration, mix the silver waste produced in this activity in a saturated sodium chloride solution to produce stable silver chloride.
• The mirrored silver vial made in this activity is for decorative purposes only and should not be used for food or drink.

Additional Reading: Investigating Phenomena: How Is the Silver Formation Explained?

Teacher preparation

1. Put on safety glasses and gloves.
2. Combine about 100 mL of tap water and 40 g of sodium chloride in a 600-mL beaker. Stir to dissolve most of the salt. This beaker of saltwater serves as the waste container for all silver-containing waste.

Student procedure

1. Put on safety glasses and gloves.
2. Combine about 100 mL of tap water and 40 g of sodium chloride in a 600-mL beaker. Stir to dissolve most of the salt. This beaker of saltwater serves as the waste container for all silver-containing waste.
3. Prepare a 5% dextrose solution by adding 30 mL of deionized water to 1.5 g of dextrose. Prepare the ammonium nitrate.
4. Using a pipet, transfer about 2 mL of acetone to the vial, and secure the lid. Shake the vial to distribute the acetone and cover the interior of the vial. Remove the lid, empty the vial into a waste container, and allow the lid and vial to air dry.
5. Using a pipet, transfer 2.0 mL of silver nitrate to the vial.
6. Using a pipet, transfer 2.0 mL of ammonium nitrate to the vial.
7. Using a pipet, transfer 2.0 mL of dextrose solution to the vial.
8. Using a pipet, transfer 2.0 mL of sodium hydroxide to the vial.
9. Put the lid on the vial, and swirl the vial for about 2 minutes to distribute the solution over the entire interior surface of the vial. You should begin to see a silver coating form on the inside of the vial.
10. After swirling for 2 minutes, remove the lid from the vial, and pour the vial’s contents into the waste beaker of saltwater. Important: To prevent formation of explosive silver compounds, it is important that the waste container contain a saturated sodium chloride solution. See step 4.
11. Rinse the inside of the vial with tap water and pour the contents into the waste beaker. Allow the inside of the bottle to dry before sealing lid.
12. The silver vials can easily be strung into holiday decorations using twine, wire, or string.