Question

Which one of the following processes involve chemical reactions?

पर्याय

• Storing of oxygen gas under pressure in a gas cylinder

•  Liquefaction of air

• Keeping petrol in a china dish in the open

• Heating copper wire in the presence of air at high temperature.

Answer 1

Heating copper wire in the presence of air at high temperature.

Explanation -

Copper will react with oxygen present in air upon strong heating to form copper (II) oxide or cupric oxide.

`2"Cu"+ underset(("Air"))("O"_2) overset("Heat")(->) 2"CuO"`