Abstract
The reaction of the formation of complex salt between cupric and citrate ions was investigated with spectrophotometer. It was found that stable cupric citrate was formed in the range of pH 5.5-12.0, and its dissociation constant was 7.80×10-6 at pH 7.0.
By the application of the above complex salt solution to the electroplating bath for copper, adherent and lustrous deposit of copper was obtained on steel.
The composition of the electrolyte and the conditions of electrolysis are as follows.
Cupric sulfate 0.5mol/l
Sodium citrate 1.0mol/l
pH 4.0-5.0
Temperature 40-50°C
Cathode current density 0.3-0.8A/dm2
