[shehri]

Hi friends,

              Plz. tell me the purpose behind using reducing & oxidizing flames in Borax-bead tests seperately.Thanks.

[shelanachium]

In an oxidising flame a metal is converted to a high oxidation state if it has several e.g copper will be Cu2+, iron Fe3+ and so on. In a reducing flame a lower oxidation state or even free metal will be produced. The colours of the bead produced will therefore be different, often revealing the metal which is present. For example iron gives Fe2+ (green) in a reducing flame, but Fe3+ (brown or yellow) in an oxidising flame; easily reducible metals such as Pb, Ag give grey or black in a reducing flame (finely divided free metal) and colourless in oxidising.

[shehri]

Thanks for giving worthwhile infos.