Why not use chromium as chromium plating anodes?

A: The use of soluble chromium chrome not as an anode, mainly it is highly soluble chromium plating process. Dissolved chromium anode current efficiency is greatly higher than the cathode current efficiency of the deposition of chromium. Thus, as for the plating process, will inevitably result in higher and higher chromium content in the bath, makes it impossible to achieve normal plating. And with chromium as an anode, it is mainly in the form of trivalent chromium ions dissolved into solution, the plating solution of trivalent chromium ion accumulation. And because the chromium is brittle, difficult to process into various shapes, it is not used as an anode whole chromium, generally used as a lead or lead alloy anode chromium plating process.
20 chrome plated layer brown film produced in part, this is why?
A: The chrome layer produced some brown film, mainly caused by insufficient sulfate. In addition, the bath temperature is too low or by impurities (such as Cl-) interference, but also in chrome plating to produce a brown film.
21 What is electrolysis?
A: When the current through the electrolyte, the electrode redox reactions occurring in the current role of the electrolyte by the electrolytic process is called decomposition. Energized toward the cathode electrolyte cations and electrons in the cathode is reduced to obtain new substances; anion towards the anode, and the loss of electrons at the anode is oxidized to the new substances. Sometimes also occurs on the anode oxidation of the electrode material. Such as electrolysis of molten sodium chloride.
NaCl → Na + + Cl-
Cathode Na + + e → Na
Anode 2Cl - 2e → Cl2 ↑
Electrolysis industry in the national economy plays a huge role in many non-ferrous and rare Molybdenum tube smelting, chemical industrial products, preparation and electroplating, electrolytic polishing, anodizing, etc. are to be achieved through electrolysis.
22 What is electroplating?
Answer: By the electrolysis, the metal is deposited on the workpiece surface a thin layer of another metal method, called plating. Plating including pre-plated (degreasing, rust), plated metal plating layer and post-treatment (passivation, except hydrogen) and other processes. Used to prevent metal corrosion, repair of worn parts, increased durability, reflectivity, conductivity and aesthetic. Plating the metal parts as a cathode, the plated metal plates or rods as an anode, were hanging in the bar at a copper electrode immersed in the electrolyte containing the coating composition, which leads to direct current.
In individual cases, but also useful insoluble anode, for example, chromium plating with lead or lead-antimony alloy anode.