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Silver ornaments become black after some time because silver reacts with ________ present in the air.
oxygen
nitrogen
sulphur
carbon dioxide
sulphur
Silver ornaments turn black over time due to a chemical reaction known as tarnishing, which occurs when silver reacts with sulphur compounds present in the air. This process results in the formation of a thin layer of silver sulphide on the surface of the metal.
Silver ornaments turn black over time due to a chemical reaction known as tarnishing, which occurs when silver reacts with sulphur compounds present in the air. This process results in the formation of a thin layer of silver sulphide on the surface of the metal.
Just as iron rusts when exposed to moisture and air, silver 'rusts' (tarnishes) when exposed to sulphur, like a slow-motion chemical skin change.
Ag-S (Silver-Sulphur) = Black Smudge
2Ag+H2тАЛS+21тАЛO2тАЛтЖТAg2тАЛS+H2тАЛO тАФ The corrosion reaction of silver
The corrosion of silver is a chemical process where silver (Ag) reacts with hydrogen sulphide (H2тАЛS) present in the atmosphere, often as a pollutant. The chemical equation for this reaction is 2Ag+H2тАЛS+21тАЛO2тАЛтЖТAg2тАЛS+H2тАЛO. The product, Ag2тАЛS, is a black-colored compound that forms a protective, though unsightly, layer over the silver ornament.
Silver is a noble metal but reacts readily with sulphur.
The black layer is specifically silver sulphide (Ag2тАЛS).
Tarnishing is a form of surface corrosion.
Understanding metal preservation techniques.
Cleaning of silverware using electrochemical reduction.
Sulphur in the air is often released from industrial processes or the decomposition of organic matter.
Option A (oxygen) causes iron rusting but not the blackening of silver. Option B (nitrogen) is inert at room temperature. Option D (carbon dioxide) does not react with silver.
C is correct тАФ Silver ornaments become black due to the formation of silver sulphide upon reaction with sulphur compounds in the air.
Always remember that different metals show different oxidation products: Iron forms reddish-brown iron oxide, while silver forms black silver sulphide.
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