Question

Some articles made of silver, copper and iron get coloured coating over them when they are exposed to air. Identify the colour and chemical name of the substance of coating in each case.

Plzzzz answer fast....

Answer 1

Hi,

The process is called Corrosion

Different metals have different colours whet it is corroded,

• Silver  - Black colour when corroded - 2Ag + O2 = Ag2O ( Silver Oxide )
• Copper - Green colour when corroded - 4Cu + O2 = 2Cu2O (Copper Oxide)
• Iron - Reddish - Brown colour when corroded - 4Fe + 6H2O = 2Fe2O3 + 6H2 ( Iron Oxide or Rust )

Thanks

MENTOR90