Baby Battery

Chemicals and Solutions

  • Strips of Magnesium and Copper
  • 0.5 M copper sulfate
  • 0.5 M sodium sulfate

Materials

  • 600 mL beaker with one holed rubber stopper to fit
  • dialysis tubing
  • two alligator/alligator leads
  • flash light bulb in a small lamp holder

Procedure

  1. Cut about 6 inches of dialysis tubing and soften it in water. Tie off one end with a double knot to make a leak proof bag.
  2. Fill the bag 2/3 full with 0.5 M copper sulfate solution. Then place a long thin strip of copper into the copper sulfate solution such that one end of the strip sticks out of the bag.
  3. Place the prepared bag in a 600 mL beaker.
  4. Fill the beaker about half full with 0.5 M sodium sulfate.
  5. Place a long strip of magnesium in the sodium sulfate solution such that one end of the strip is above the lip of the beaker.
  6. Stopper the apparatus such that the dialysis bag and the metal strips are held in place. The top of the bag and the tops of the metal strips will be sticking out.
  7. Use alligator leads to connect the metal strips to the light bulb. The bulb will light up.

Discussion

The reaction:

\( \ce{ Mg_{(s)} + Cu2+_{(aq)} -> Mg2+_{(aq)} + Cu_{(s)} + 1.5V } \)

Electrolysis of water produces bubbles of hydrogen and oxygen gas.