Container made of Copper metal on exposure to air for longtime turns green. The green layer is due to
CuO
CuCO3.Cu(OH)2
CuSO4.3Cu(OH)2
All of the above
Container made of Copper metal on exposure to air for longtime turns green. The green layer is due to
CuO
CuCO3.Cu(OH)2
CuSO4.3Cu(OH)2
All of the above
The correct option is B CuCO3.Cu(OH)2
Corrosion of metals
The reaction of metal atoms on the surface of a metal with the atmospheric gases when exposed to air is called corrosion. The atmospheric gases include Oxygen (O2), Carbon dioxide (CO2), moisture etc. This causes a gradual degradation of the metal and change in its appearance.
Corrosion of Copper
When Copper (Cu) is exposed to air for a long time, the metal reacts with different atmospheric gases to form more than one products which forms a layer on the surface of the metal. The reaction of copper with Carbon dioxide, Oxygen and moisture in air produces Copper carbonate (CuCO3) and Copper hydroxide [Cu(OH)2].
The chemical equation for the reaction is:
(Copper) (Oxygen) (Carbon (Moisture) (Cupric (Copper
dioxide) hydroxide) carbonate)
The presence of Cupric hydroxide makes the Copper carbonate basic. Basic Copper carbonate is green in colour and forms a layer on the copper surface .
Since Cupric oxide (CuO) is not formed in the reaction, option (A) is incorrect.
Cupric hydroxide and Copper carbonate is formed in 1:1 ratio. Therefore, option (B) is correct and (C) is incorrect.
The correct option is (B) CuCO3.Cu(OH)2
CuCO3.Cu(OH)2
Corrosion of metals
The reaction of metal atoms on the surface of a metal with the atmospheric gases when exposed to air is called corrosion. The atmospheric gases include Oxygen (O2), Carbon dioxide (CO2), moisture etc. This causes a gradual degradation of the metal and change in its appearance.
Corrosion of Copper
When Copper (Cu) is exposed to air for a long time, the metal reacts with different atmospheric gases to form more than one products which forms a layer on the surface of the metal. The reaction of copper with Carbon dioxide, Oxygen and moisture in air produces Copper carbonate (CuCO3) and Copper hydroxide [Cu(OH)2].
The chemical equation for the reaction is:
(Copper) (Oxygen) (Carbon (Moisture) (Cupric (Copper
dioxide) hydroxide) carbonate)
The presence of Cupric hydroxide makes the Copper carbonate basic. Basic Copper carbonate is green in colour and forms a layer on the copper surface .
Since Cupric oxide (CuO) is not formed in the reaction, option (A) is incorrect.
Cupric hydroxide and Copper carbonate is formed in 1:1 ratio. Therefore, option (B) is correct and (C) is incorrect.
The correct option is (B) CuCO3.Cu(OH)2
