GROUP II PRELAB

The $pH$ is adjusted to $0\mathrm{.}5$ and thioacetamide is added to an unknown containing Group II

cations. A black precipitate is formed, insoluble in NaOH but completely soluble in

$HN{O}_3.$ When $N{H}_3$ is added, a white precipitate forms and the solution turns deep blue.

What ion$($s$)$ is$/$are clearly absent$?$

What ion$($s$)$ is$/$are almost certainly present?

Write net ionic equations for all observations.