Problem
A Haring-Blum cell was used to evaluate the deposition power (TP) of a copper plating bath whose composition can be simplified to 195 g/L copper sulfate, 50 g/L sulfuric acid, thiourea as brightener, and surfactants. The separation between the brass cathodes and the nickel anode was 1.5 cm and 12 cm respectively, the area of the two cathodes is 6 cm2. The current density applied to the cell is 3 A/dm2, for 8 minutes and the conductivity of the bath is 0.09 -1cm-1. The amount by mass of the deposit in the nearest cathode was 0.22 g and the furthest 0.08 g.
1. Estimate the resistance of the solution between each of the cathodes and the anode,
2. Calculate the power of the deposit,
3. Is the power of the tank adequate?
4. How does elevated temperature affect the copper bath?
5. List the possible causes of burning in the zone of high current density.