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Copper(II) bromide (Cu Br 2) is a chemical compound that forms an unstable tetrahydrate CuBr 2 ·4H 2 O. It is used in photographic processing as an intensifier and as a brominating agent in organic synthesis .
Electrode potentials of successive elementary half-reactions cannot be directly added. However, the corresponding Gibbs free energy changes (∆G°) must satisfy ∆G° = – z FE°, where z electrons are transferred, and the Faraday constant F is the conversion factor describing Coulombs transferred per mole electrons. Those Gibbs free energy ...
The reaction at the anode results in chlorine gas from chlorine ions: 2 Cl − → Cl 2 + 2 e −. The reaction at the cathode results in hydrogen gas and hydroxide ions: 2 H 2 O + 2 e − → H 2 + 2 OH −. Without a partition between the electrodes, the OH − ions produced at the cathode are free to diffuse throughout the electrolyte to the ...
The exact relationship depends on the nature of the reactions at the two electrodes. For the electrolysis of aqueous copper(II) sulfate (CuSO 4) as an example, with Cu 2+ (aq) and SO 2− 4 (aq) ions, the cathode reaction is the reduction Cu 2+ (aq) + 2 e − → Cu(s) and the anode reaction is the corresponding oxidation of Cu to Cu 2+.
Copper at red heat (300-400°C) combines directly with chlorine gas, giving (molten) copper(II) chloride. The reaction is very exothermic. [8] [15] Cu(s) + Cl 2 (g) → CuCl 2 (l) A solution of copper(II) chloride is commercially produced by adding chlorine gas to a circulating mixture of hydrochloric acid and copper. From this solution, the ...
Reaction 1 is discarded as it has the most negative value on standard reduction potential thus making it less thermodynamically favorable in the process. When comparing the reduction potentials in reactions 2 and 4, the oxidation of chloride ion is favored over oxidation of water, thus chlorine gas is produced at the anode and not oxygen gas.
This reaction is accomplished with the use of copper(II) chloride (CuCl 2) as a catalyst and is performed at high temperature (about 400 °C). The amount of extracted chlorine is approximately 80%. Due to the extremely corrosive reaction mixture, industrial use of this method is difficult and several pilot trials failed in the past.
Electrorefining copper. Electrowinning is the oldest industrial electrolytic process. The English chemist Humphry Davy obtained sodium metal in elemental form for the first time in 1807 by the electrolysis of molten sodium hydroxide. Electrorefining of copper was first demonstrated experimentally by Maximilian, Duke of Leuchtenberg in 1847. [2]