I made a batch of sodium aluminate by mixing sodium hydroxide solution with pure aluminum pellets. I added an excess of aluminum just to make sure all the sodium hydroxide was gone. Once done I added a copper sulfate solution to it and got a dark bluish green solid. However I saw this on wikipedia and worried this might effect my results. "Sodium aluminate is also formed by the action of sodium hydroxide on elemental aluminium which is an amphoteric metal. The reaction is sometimes written as: 2 Al + 2 NaOH + 2 H2O → 2 NaAlO2 + 3 H2however the species produced in solution is likely to contain the [Al(OH)4]? ion or perhaps the [Al(H2O)2(OH)4]" So I was concerned that I made copper hydroxide instead of copper aluminate. As a test I know I can heat the hydroxide and see if it turns to black copper oxide. But I don't know what will happen if I heat copper aluminate. What should I do to make sure I made copper aluminate?
System copper oxide-alumina [that is CuO + Al2O3 →Δ→ ] By Misra, S. K.; Chaklader, A. C. D. From Journal of the American Ceramic Society (1963), 46(10), 509. The cmpd. Cu(AlO2)2 forms at about 800° presumably by a solid-state reaction, and is stable to about 1000° in air, then is converted to CuAlO2, which is stable to about 1260° in air. CuO and CuO2 coexist between 900 and 1000°. CAS Registry Number: 12042-92-1 copper aluminate Could find nothing that looks like your synthesis so my guess is that your prep yields Cu(OH)2 ~20
