REMOVING SILVER TARNISH

 

Silver is such a lovely metal to work with and has some stunning results. Over time however the initial lustre can tarnish, and the surface covered with a black coating of silver sulphide. A common way to remove this is to polish it off. This is an abrasive method and can remove small amounts of silver too, and after many years you can notice the difference.

 

To avoid this gradual removal of silver, chemistry has a fantastic hack using things you would already have in the kitchen. Line a bowl with aluminium foil, add roughly 1 teaspoon of bicarbonate soda, a pinch of salt and add boiling water. Place the tarnished silver object in the water making sure it is in contact with the aluminium foil and the tarnish will disappear.

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~ Science snippet! ~

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Silver is tarnished when in contact with hydrogen sulphide in the air as follows.

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2 Ag(s) + H2S(g) → Ag2S(s) + H2(g)

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The sulphur prefers to be on the aluminium, so under the correct conditions, it will jump from the silver following this reaction.

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3 Ag2S(s) + 2 Al(s) → 6 Ag(s) + Al2S3(s)

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