8 grade science> why is copper when exposed to moist air t...

why is copper when exposed to moist air turn their layer into green coating ?

suraj , 8 Years ago

Grade 8

5 Answers

Arun

Dear Suraj
green coating appears on the surface of copper vessel because the copper on getting exposed to moist air slowly forms calcium carbonate and copper hydroxide which is called tarnish . the statue of liberty has turned green because of tarnish
it can be reprsented as :- h²o +co² +o² +cu = cu {oh}² +caco³
Regards
Arun (askIITians forum expert)

Last Activity: 8 Years ago

Akachdeep Medhi

Copper develops a green coating when it s exposed to humid air containing CO2.A reaction takes place with CO2 and moist air (H2O) and forms basic copper carbonate{CuCO3.Cu(OH)2}.This compound is green in colour.

With regards Akash.

Last Activity: 7 Years ago

amisha

copper turned into green coating because of corrosion

coroision is a process in which metal layer is eaten up when exposure to air and water .

hence due to exposure the copperstarts corroding and turned into green coating

Last Activity: 7 Years ago

Siddharth Singh

Dear Surajgreen coating appears on the surface of copper vessel because the copper on getting exposed to moist air slowly forms calcium carbonate and copper hydroxide which is called tarnish . the statue of liberty has turned green because of tarnishit can be reprsented as :- h2o +co2 +o2 +cu = cu {oh}2 +caco3Regards

Last Activity: 7 Years ago

Scholr Boy

Copper metal when exposed to air turns green in colour due to corrosion. When copper vessel is exposed to air in rainy season, the metal reacts with gases and moisture and atmospheric gases to form a mixture of copper carbonate and copper hydroxide. This gives a green colour to the surface of copper metal.

The reaction is as follows:

2Cu + H₂O + CO₂ + O₂ → Cu(OH)₂ + CuCO₃

Last Activity: 7 Years ago