Redox Lab Manual
Test for Oxidising and Reducing
The concept of redox reactions is
used to test for the presence of oxidising and reducing
A reducing agent is added to the
unknown substance to detect it's oxidising nature. The
reducing agent brings about reduction of an oxidising
agent. Common reducing agents used in QA are potassium
iodide, sodium sulphite and sodium thiosulphate.
An oxidsing agent is added to the unknown substance
to detect its reducing nature. The oxidising agent brings
about oxidation of a reducing agent. Common oxidising
agents used in QA are acidified potassium dichromate(VI),
acidified potassium manganate(VII), hydrogen peroxide,
reactive metals and oxygen.
In both cases, the reaction between
reducing and oxidising agent and vice versa result in
observable changes in colour, formation of precipitates
or liberation of gases.