JEE Main 2014 · 12 Apr · Shift 1 · Chemistry Q44

ChemistrySingle correct+4 / -1Question 44 of 90

Copper becomes green when exposed to moist air for a long period. This is due to :

the formation of a layer of cupric oxide on the surface of copper.

the formation of a layer of basic carbonate of copper on the surface of copper.

the formation of a layer of cupric hydroxide on the surface of copper.

the formation of basic copper sulphate layer on the surface of the metal.

Answer and worked solution

Official answer: B

Moist air with $\ce{CO2}$ forms a green layer of basic copper carbonate, $\ce{CuCO3.Cu(OH)2}$ .

JEE Main 2014 · 12 Apr · Shift 1, Chemistry question 44