Potassium carbonate developing agents

Uses As a developing agent used in conjunction with sodium or potassium carbonates or with caustic alkali. The sodium salt of this is the developing agent in the concentrated solution of prepared developer. It is marketed under the trade name of Rodinal by Agfa. 

In all of these reactions, the diaryl tellurium oxide is reduced to the diaryl tellurium. To make the conversion of thiocarbonyl to carbonyl groups catalytic with respect to the diaryl tellurium oxide, the diaryl tellurium must be converted back to the diaryl tellurium oxide. A catalytic cycle was developed with 1,2-dibromotetrachloroethane as the agent oxidizing the diaryl tellurium to the diaryl tellurium dibromide and 20% aqueous potassium carbonate as the base hydrolyzing the tellurium dibromide to the tellurium oxide1. 

Applications Potassium hydroxide is utilized in the manufacture of other potassium compounds (potassium carbonate, potassium phosphates e.g. tetrapotassium pyrophosphate, potassium permanganate, potassium bromate, potassium iodate, potassium cyanide etc.), of dyes, special soaps and battery liquids. It is also used in photographic developers, in glass manufacture and as a drying and absorption agent. In many of these applications its use is declining. 

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