When cadmium cyanide complexes are oxidized, which form of cadmium precipitates out of the solution?

When cadmium cyanide complexes undergo oxidation, the oxidation process breaks down the cyanide ligand from the cadmium complex. As a result of this reaction, cadmium is freed and can combine with various anions present in the solution. The significant outcome of this process is the formation of cadmium oxide.

Cadmium oxide is an insoluble precipitate that occurs due to the reaction of cadmium ions with oxygen or hydroxide ions that may be present during the oxidation process. This precipitation is a common result of cadmium being converted from its soluble complex form to a solid state, effectively removing it from the solution and thus reducing its toxicity in wastewater.

In contrast, other potential forms such as cadmium sulfate, cadmium chloride, and cadmium hydroxide do not typically form under oxidative conditions involving cadmium cyanide. The specific conditions and chemistry of the oxidation process favor the formation of cadmium oxide as the stable precipitate in this scenario.