Electroplating involves using electric current to reduce metal ions in a solution and thereby to coat an electrode. Electroplating copper in a zinc sulphate solution coats the copper in a thin patina of zinc. By covering the copper with masking tape first, you can create a design on the surface of the copper. A simple experiment with a small copper sheet is a good place to start. If you've mastered this experiment and want to move on, you might try electroplating copper pennies as well.
Put on your lab coat, chemical splash goggles and gloves to ensure your personal safety.
Mix up a zinc sulphate solution by adding 12 grams of ammonium citrate, 7.5 grams of ammonium chloride and 30 grams of zinc sulphate heptahydrate to 300 millilitres of water.
Polish both sides of the copper sheet with the steel wool. The cleaner you can get the copper, the better.
Rinse the copper then dry it and polish it some more. Finally, rinse the copper again and dry it.
Drill a hole in the copper sheet. You'll use this hole to hang the copper plate from a hook later on. Be very careful when drilling through the copper--make sure you clamp it in place before you try to drill it, and do not attempt to carry out this part of the procedure if you've never used an electric drill before or are unfamiliar with its use.
Cover the copper completely on both sides with masking tape. The tape should cover not only the two surfaces but also the edges.
Draw a design of your choice on the masking tape with a pen. Remove the masking tape in the area of your design with a razor blade. Be careful not to cut yourself--a razor blade is extremely sharp.
Clean the exposed copper surface with a cotton swab and rubbing alcohol.
Bend a 10-cm long piece of heavy gauge copper wire into a hook and insert it through the hole in the copper plate. It's essential that the copper hook makes contact with the plate itself and not just the tape. Inspect the copper plate to make sure the hook is in direct contact with the copper.
Add some of your zinc sulphate solution to the 250-mL beaker. Don't fill the beaker; just add enough that the design on your copper plate will be completely covered once it's submerged.
Bend the zinc strip so it's shaped like a hook and hang it from the lip of the beaker, with the hanging end submerged in the zinc sulphate solution.
Connect a wire from the zinc to the positive terminal of your battery. Connect the other wire from the negative terminal to the copper wire hook attached to the copper plate.
Suspend the copper plate in the solution in your beaker on the side opposite the zinc strip. Do not allow the zinc strip and the copper sheet to come in direct contact.
Check your progress at intervals by removing the copper plate and examining it to see how much zinc has been deposited. Once the copper has accumulated the amount of zinc you want, place paper towels beneath a ring stand in a well-ventilated area, then hang the copper sheet from the ring stand to dry.
Always be careful when working with an electric current. Do not ingest any of the chemicals named in this procedure or solutions of these chemicals; do not allow them to come in prolonged contact with your skin either. Work in a well-ventilated area and clean up properly once you are done.
Tips and warnings
- Always be careful when working with an electric current.
- Do not ingest any of the chemicals named in this procedure or solutions of these chemicals; do not allow them to come in prolonged contact with your skin either. Work in a well-ventilated area and clean up properly once you are done.
Things you need
- Razor blade
- Masking tape
- Steel wool
- 4-cm-square piece of copper
- Electric drill and 3/32 drill bit
- 250-mL beaker
- 500-mL beaker
- Rubbing alcohol
- 4 inches of bare heavy copper wire
- C battery and wire leads
- Cotton swabs
- Ammonium citrate
- Ammonium chloride
- Zinc sulphate heptahydrate
- Chemical splash goggles
- Lab coat
- Zinc strip