The consumption of ammonia, which had been added to a copper pyrophosphate plating bath, was investigated, and the following conclusions were drawn.
The consumption of ammonia per unit time was greater with the increase of its content in the bath. The changes in the amount of ammonia with the lapse of time in the bath were expressed by an exponential function.
Its amount of consumption depended upon temperature and pH of the bath and conditions of agitation (flow rate of air), but little upon the current. The amount was greater with higher temperature, higher value of pH, and more violent agitation.

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The sorption of coconut-core active carbon for automatic elimination of organic impurities, oxidized or reduced substances of 2-butyne-1·4-diol, in bright nickel plating bath was investigated.
The results obtained were as follows:
1) The sorption points of acidic impurities and alcoholic ones were different each other.
2) Much more 2-butyne-1·4-diol (brightener) was sorbed than its oxidized or reduced substances (acidic or alcoholic impurities).
3) The process of automatic or semi-automatic elimination of the organic impurities was preferable to conduct in the following order of sequence.
(a) Passing through 30g/l of coconut-core active carbon of 30-50 mesh about 5 times for elimination of the brightener.
(b) Adding 0.1g/l of KMnO₄ to the solution.
(c) Dissolving the precipitate obtained (MnO₂) with 0.143ml/l of 30% H₂O₂.
(d) Passing through the active carbon layer, used in the process of (a), more than 9 times for more than 1hr.

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The chemical films of chromate conversion treatment were formed on galvanized iron sheets under various conditions.
The surface potentials were approximately constant at about 1.15V vs. Au surface under any conditions. The surface potential was decreased with higher temperature and an approximate relation was observed between the surface potential and adhesive properties of organic coatings.

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The comparison of electrolytic characteristics of gold plating and corrosion resistance of the deposits was studied between cyanide and citrate baths under various conditions.
The following results were obtained.
(1) The optimum conditions for good adhesion of gold in cyanide striking bath were as follows:
KAu(CN)₂……more than 3g/l Bath temperature……lower than 50°C
Free KCN…… more than 60g/l Dk……less than 0.75 Amp./dm²
K₂CO₃…… more than 30g/l Plating time less than 20sec.
(2) The optimum conditions for good brightness, good color tone, and high current density in cyanide bath were as follows:
KAu(CN)₂……5g/l pH……12
Free KCN……50g/l Bath temperature……60°C
K₂CO₃……30g/l Dk……0.1Amp./dm²
K₂HPO₄……20g/l Violent stirring
The above optimum conditions in citrate bath were as follows:
KAu(CN)₂……10g/l pH……4.5
Na citrate……50g/l Bath temperature……60°C
Citric acid……30g/l Dk……0.5Amp./dm²
KH₂PO₄……140g/l Violent, stirring
Free KCN……1.5g/l
(3) Throwing power of deposits from cyanide bath was superior to that from citrate bath. High power was obtained at 50g/l of free cyanide in cyanide bath and at pH of 4-5 in citrate bath.
(4) Porosity of deposits from citrate bath was far lower than that from cyanide bath. It was increased with the increase of pH or free cyanide.
(5) Corrosion resistance depended upon porosity. Rusting rate of deposits from citrate bath was lower than that from cyanide bath by the results of salt spray and nitric acid fume tests. The results of salt spray tests showed that the rate was 50% or more in the deposits from cyanide bath and 50% or less in those from citrate bath.
(6) Heat resistance did not depend upon the porosity, but depended upon the discoloration due to diffusion of the substrate metal. Gold deposits except for on nickel substrate were discolored by heating at above 300°C.

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It has been about 10 years since the titanium electrode plated with platinum appeared in electrochemical industry, and it has been evaluated as an excellent insoluble electrode. It is said that more than dozens of patents on the manufacturing method of this electrode have been published. However, the electrode having very high corrosion resistance has never been manufactured.
The activation energy for the interface reaction between titanium and the acid was calculated from the measured rate of dissolution of titanium in hydrofluoric acid, and the mechanism of dissolution of titanium was estimated as an essential factor in plating platinum on titanium in aqueous solution.
The following results were obtained.
1) The change in activation energy of titanium in hydrofluoric acid with the concentration of acid was as follows:
Concentration Activation energy 2% 9.5Kcal.mol^-1
1% 9.7Kcal.mol^-1
0.5% 9.3Kcal.mol^-1
2) The change of energy, when the solution was being stirred, was as follows:
Concentration Activation energy
2% 9.7Kcal.mol^-1
1% 9.6Kcal.mol^-1
0.5% 9.4Kcal.mol^-1
3) Almost the same values of activation energy were obtained between the solution with and without stirring, even though the reaction rate was not determined owing to the diffusion by stirring. Therefore, it was concluded that the reaction rate is not determined by the diffusion process.

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