Cu; Titrated with EDTA during warm by using PAN as indicator.
P₂O₇; After Cu was estimated, the solution was adjusted at pH=3.8-4.0 with CH₃COOH, and made Zn₂P₂O₇ to precipitate by adding Zn. The precipitate was filtered off, and the excess of Zn⁺⁺ in the filtrate was titrated with EDTA during warm at pH=10.
PO₄; After P₂O₇ was estimated, the solution was added with Mg⁺⁺ to precipitate MgNH₄PO₄⋅6H₂O.
After the precipitate was filtered off, the excess of Mg⁺⁺ was titrated with EDTA during hot.
End point of the titration of P₂O₇ and PO₄ was determined with Cu-PAN indicator. The indicator was the mixture of PAN, added for Cu-estimation, with Cu-EDTA, produced by the titration.
In the process of electrolysis, a part of P₂O₇ was converted into PO₄, and some other parts were separated with the electrodeposited copper (its content of P was about 0.09%).

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Evaluation was made on the corrosion resistance of lead and lead alloys (containing each of Bi, Zn, Sn, Sb, Te, Ni, Ag, and Cu) in 50°Bé sulfuric acid by immersion test during a considerably long period. The period required was more than 10 weeks at minimum, especially 25 weeks at optimum.
The change of weight by corrosion with time shown in curves, was classified into the following 3 types.
(1) The resistance was lower than that of pure lead; Alloys containing each of Bi and Zn.
(2) The resistance was almost the same as that of pure lead; Alloys containing each of Sn and Sb (in the limit of solid solution).
(3) The resistance was higher than that of pure lead; Alloys containing each of Te, Sb (over the limit of solid solution), Ni, Ag, and Cu.

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Experiments were conducted to study the relations between concentration and brightness range, current efficiency, or throwing power, etc. in potassium cyanide baths for high-speed and high-efficiency copper plating.
The comparison of the above data was made between potassium and sodium cyanide baths.
As the results, the plating in potassium cyanide bath was superior to that in sodium cyanide on brightness range, current efficiency, and throwing power. Accordingly, potassium cyanide bath is preferable to high-speed and high-efficiency plating.
No significant differences were observed between the both baths on hardness and stress.

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