Materials

• 9V transistor battery
• 9V transistor battery connector with color coded lead wires
• (2) small alligator clips
• 250ml beaker
• 175ml of 3M KCl
• 1 roll of 36g silver wire (0.005” dia)
• #2 pencil
• dental wax or clay
• forceps

Procedure

1. Attach an alligator clip to the each lead of the 9V transistor battery connector.
2. Pour the 3MKCl solution into the beaker.
3. Wrap a 30cm length of the silver wire around the pencil to form a coil of ten turns. At one end of the coil, there should be a straight segment about 3cm long. Make two coils for each chloriding session.
4. Put two 1” long beads of dental wax or clay on opposite sides of the rim of the beaker.
5. Attach a coil of silver wire to each lead of the battery connector by clamping the straight segment of the wire in the jaws of the alligator clip.
6. Position each alligator clip in the wax or clay on opposite sides of the rim of the beaker, so that the two wire coils are in solution.
   NOTE: It is important that one wire coil does not touch the other, and that the alligator clips or the lead wires of the battery connector are not in solution!
7. Attach the 9V transistor battery to the battery connector. The solution near the coils will bubble and the coils will change color during the chloriding procedure.
8. Chloride the coils for 8 minutes.
9. Disconnect the 9V battery from the connector.
10. Reverse the chloriding process by putting each coil of silver wire on the other alligator clip. Use the forceps to hold a coil as it is removed from an alligator clip and moved to the other.
11. Position the alligator clips back on the wax and make sure the wire coils in the solution.
12. Attach the 9V battery to the connector and chloride the wire coils in this polarity for another 8 minutes.
13. At the end of the second 8-minute period of chloriding, put the wire coils back on the alligator clips to which they were initially attached and chloride the coils in this configuration for 5 minutes.
14. Finally, reverse the chloriding of the coils, as performed in Steps 9 and 10, for 5 minutes.
15. At the end of the 5 minutes, disconnect the battery, remove the wire coils from the clips, and rinse the coils with deionized water.
16. The coils of chlorided silver wire are now ready to be used as electrodes.