If copper is kept open in air, it slowly loses its shining brown surface and gains a green coating. It is due to the formation of

(A) CuSO 4

(B) CuCO 3

(C) Cu(NO 3 ) 2

(D) CuO



Copper corrodes in the presence of air and moisture

Because of the CO 2 and O 2 present in the air, Cu reacts with them to form CuCO 3  which is green in color.

The reactions take place as:

Reaction for Corrosion of Copper - Teachoo.png


So, the correct answer is (b) CuCO 3

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Maninder Singh

CA Maninder Singh is a Chartered Accountant for the past 14 years and a teacher from the past 18 years. He teaches Science, Economics, Accounting and English at Teachoo