Question 16 - MCQs from NCERT Exemplar - Chapter 3 Class 10 - Metals and Non-Metals

Last updated at August 4, 2026 by

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

 

Answer

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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