Antimony, Sb3+
Most common oxidation states: +3, +5
M.P. 630o
B.P. 1380o
Density 6.69 g/cm3
Characteristics: Brittle, silvery. Not very active, but reacts with oxygen, sulfur and chlorine at high temperatures.
Characteristic reactions of Sb3+:
(Sb(III) is the more stable oxidation state.)
Chloride Ion:
No reaction observable, but will be present as SbCl4.
Aqueous Ammonia:
Sb(III) reacts with aqueous ammonia to precipitate white Sb(OH)3.
Sodium Hydroxide:
Sodium hydroxide also precipitates Sb(OH)3, which is amphoteric and dissolves in an excess of hydroxide and in acids.
Hydrogen Sulfide:
Under moderately acidic conditions, H2S precipitates red Sb2S3.
This sulfide is soluble in solutions of hot NaOH which contain excess sulfide ion and in hot, concentrated (12 M) HCl.
Water:
Solutions of antimony(III) chloride in HCl react when added to excess water to form the basic, white, insoluble salt SbOCl.
Reducing Agents:
In the presence of HCl, either aluminum or iron will reduce Sb3+ to Sb metal, which will be deposited as black particles.
No Reaction:
SO42-