Question

Copper does not burn but the hot metal is coated with a black coloured layer of copper 2 oxide why

Answer 1

Hey dear,

● Explanation -
Copper metal when exposed to hearing in air, oxygen reacts with copper surface forming thin layer of copper oxide over it.
2Cu + O2 --> 2CuO

This cupric oxide is already burnt and can't go reaction further. This layer being coated on pure copper, protects it from oxygen.

Therefore, whole copper doesn't burn, instead black coat of copper oxide is formed over it.

Hope this helps you...

Answer 2

Answer:

At normal temperature, the surface of copper is covered with copper oxide. The thin layer of copper oxide is a protective cover which protects copper from further oxidation. Thus this copper oxide does not burn as it is already reacted with the oxygen in the air.