I am working on an experiment with a voltaic cell and I want to build one that has two half cells one with zinc and zinc sulfate in solution and the other with copper and a copper sulfate solution, and a salt bridge connecting the two half cells. Can someone tell me how to build a salt bridge? I would rather not buy a kit.
See attached link to and have fun!
Preparation Of Salt Bridge
Option 1: If you have access to a lab, you can use a glass U-tube. Fill it up with a solution of something like ammonium nitrate, or some other salt whose ions do not form precipitates with any other ions. Use two cosmetic cotton puffs to plug in both ends, and invert it quickly into both solutions (presumably in separate glass beakers) taking care not to allow any air to enter the U-tube. When the circuit is complete by connecting the zinc and copper electrodes to a voltmeter, the current will flow showing you the cell voltage. Option 2: If you do not have beakers and U-tube, you can use any type of cups or glasses for each solution. The simplest salt bridge could be just a rolled up sheet of paper towel with each end inserted in different solution. When the capillary action causes each liquid to travel up the paper towel rope, the circuit will be complete when the two solutions meet. Option 3: Another alternative is to use a piece of Tygon clear plastic tubing about 1/2 inch in diameter that you can probably get in any hardware store. Bend it into a U-tube shape using some wire to keep it in that shape. Then do the procedure described in option 1.
