Precipitation and reduction of thiosulfate with silver nitrate

Chemicals needed

distilled water

sodium thiosulfate

silver nitrate solution, diluted  GSGESUND.gif (476 Byte) Xi GSUMWELT.gif (758 Byte)  N    R 34-50/53     S (1/2)-26-45-60-61

Necessary equipment

test tube

Test procedure


The residues are to be disposed of as silver-containing waste.


At first poorly soluble silver thiosulfate is precipitated, this then reacts quickly with water to form black silver sulfide and sulphuric acid.

S2O32- + 2 Ag+ -->  Ag2S2O3

Ag2S2O3 + H2O --> AgS + H2SO4


Precipitation of silver thiosulfate/sulfide


derived from experiment 3., "Nachweis mit AgNO3", p.126,[7]