Paheli bought a statue made of copper. To her surprise it acquired a dull green coating after a couple of months. Explain the reason.
When a copper statue is exposed to moist air for along period of time it acquires a dull green coating. This dull green coating is due to formation of Copper Hydroxide[Cu(OH)2] and Copper carbonate[CuCO3] formed when copper reacts with moist air.
This Green coating is commonly known as ‘Basic Copper Carbonate’ and the process of formation of green coating on copper objects is known as corrosion of copper.
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