Silver Tree

Purpose:

To demonstrate the basic redox properties of an electrochemical cell.

Materials:

• Copper wire
• Large beaker

Reagents:

• 0.1M Silver nitrate (AgNO₃)

Hazards and PPE:

• Silver nitrate is toxic and contact with skin should be avoided.
• Wear approved safety goggles and gloves.

Protocol:

Preparation

1. Bend copper wire into the desired tree shape. Be creative!
2. Place your 'tree' in a beaker of appropriate size or hang it from a stir rod placed over the top.

Demonstration

1. Pour AgNO₃ solution into the beaker until the tree is covered.
2. After several minutes, silver crystals will form on the copper wire, and the solution will begin to turn blue.
   1. More crystals will form over the ensuing minutes, giving your tree a fuzzy appearance.

Disposal:

• Shake copper wire into the AgNO₃ solution to knock silver crystals off into the beaker.
• Dispose of copper wire in the trash.
• Vacuum filter used AgNO₃ solution through Buchner funnel to extract solid crystals.
• Allow crystals to dry and set aside for use in making future AgNO₃ solution.
• Remaining solution should be placed in a proper waste container and disposed of.

Reactions:

• Ag⁺ + e^- → Ag (E^o=0.80V)
• Cu²⁺ + 2e^- → Cu (E^o=0.34V)
• Cu_(s) + 2Ag⁺ → Cu²⁺ + Ag_(s) (E_cell=0.46V)

Citations:

1. This demo adapted from the demo library of the Chemistry department at the University of Illinois at Urbana-Champaign.

Videos:

• Silver Tree, Part 1

  mrhomescientist

  While this video features less of a tree and more of a spiral, you'll find the chemistry isn't dependent on the shape of the copper- we still see beautiful thermodynamically favorable redox chemistry!