Qualitative Analysis?

Question

If a group III unknown produces a pink precipitate with a basic solution of thioacetamide, which cations are probably absent?

Group III cations are Ni +2, Co +2, Fe +2, and Mn +2

Please explain why

Answer 1

The ones probably absent are Ni2+, Co2+, and Fe2+. The one present is Mn2+. In old qual. books, MnS is described as "flesh colored," meaning the color of caucasian skin. After people realized how offensive that could be, descriptions changed.

Thioacetamide, CH3-C(S)NH2, reacts with base to form H2S, NH3, and CH3CO2-Na+. It is a replacement for H2S itself, which was used in the 19th and 20th Cents.