Most common oxidation state = Bi³⁺ The free ion is strongly hydrolyzed, forming insoluble basic saltsOnly common oxidation state in aqueous systems Halides, nitrates, sulfate, and acetate of Cadmium are soluble in water Most cadmium salts are colorless CdS = Yellow CdO = Yellow brown Forms complex ions with common ligands (Halides, CN⁻, NH₃

1. Separation and Analysis of
Group II Ions
The Group II ions are
separated from those in Group
III by adding hydrogen sulfide
to the mixture in acidic
solution. We use an organic
precursor, thioacetamide
(CH3CSNH2), which decomposes to hydrogen
sulfide in the presence of acid according to the net
reaction
CH3CSNH2 + 2 H2O CH3CO2- + NH4+ + H2S
The Group II ions precipitate as sulfides on reaction
with S2- from H2S

2. Group 2 The copper group
Bi3+, Cu2+, Sn2+, Sn4+

3. Bi3+, Cu2+, Sn2+, Sn4+
These ions precipitate as the sulfides
from0.3M HCl containing H2S.
Group 2 The copper group
Bi3+, Cu2+, Sn2+, Sn4+
These ions precipitate as the sulfides
from0.3M HCl containing H2S.

4. Rationale: Soft acids react with a very
soft base.