Question

An unknown containing only cations of group III yields, after Step 1, a precipitate and solution. Step 1 B results in the formation of a gray black solid. Treatment with aqua regia ( HCl and hno3 mixture), Step2 leads to a Green Solution. step 3 leads to a deeply colored precipitate. Treatment of the color is supernate with nitric acid, then with aqueous ammonia, does not produce a precipitate. the step 3 precipitate is treated by step for then dissolved via step 5. addition of KSCN 2 one portion of the solution leads to a blood red color. treatment of a second portion with NaF(s) and KSCN leads to a blue solution. step 8 leads to a negative result. Based on these observations what cations are present and which are absent? Show any cations eliminated for each test.

Answer 1