Where the
world gathers for metal finishing
Q&As since 1989


-----

Electroplating from CuCl solution

I am trying to refine an old experiment that never behaved very well. Students plate copper using copper screen electrodes, two plating cells in series, one containing acidic CuSO4 and other containing acidic CuCl (with KCl added).

The CuSO4 solution behaves beautifully, giving a tight coating that survives rinsing and oven drying. The CuCl solution behaves poorly, quickly producing a barely-adhering, fluffy deposit of copper that falls off the cathode if you just look at it cross-ways.

I have solved the problem of making and keeping the CuCl solution but this is a different situtation. I know that many things are often added to plating baths to improve the quality of the plating, but I don't know where to begin.

I have about 0.5-1.0 A running through the two cells (it varies all over the place) and this gives me a resonable mass change for the CuSO4 in about 15 minutes (around 0.9 g). I can't go much slower and have a viable experiment for the students.

Any suggestions?

Steve Marsden
chemistry teacher - Studio City, California, USA
2005