Corrosion is the process of deterioration of materials, primarily metals, by chemical or electrochemical reaction with their environment. - Black coating on Silver: This is silver tarnish, caused by the reaction of silver with sulfur compounds in the air to form silver sulfide (Ag₂S). This is a form of corrosion. - Green coating on Copper: This green layer, known as patina, is formed when copper reacts with atmospheric moisture, carbon dioxide, and sulfur dioxide. It is primarily basic copper carbonate [Cu₂(OH)₂CO₃] and basic copper sulfate [Cu₂(OH)₂SO₄]. This is a form of corrosion. - Brown coating on Iron: This is rust, formed when iron reacts with oxygen and moisture in the air to form hydrated iron(III) oxide (Fe₂O₃·nH₂O). This is a common example of corrosion (rusting).
Example of corrosion is
Asked in CGPSC Prelims Exam 2016 · Topic: Metals, Minerals, Ores: Properties, Uses (Corrosion of metals: causes, mechanism (rusting), and prevention methods (galvanization, anodizing, electroplating, alloying, painting))
More Chemistry questions
- Rusting of iron is :
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- Which one of the following elements corrodes rapidly?
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- To protect steel and iron from rusting, a thin layer of which one of the following metals is applied ?
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