Question

Identify the type of chemical reaction taking place and also write the balanced chemical equation for: heating copper powder in air in a china dish, the surface of copper turns black.

Answer 1

Hint: We must know that any reaction in which heating is taking place in presence of air is known as oxidation reaction. When oxygen atoms are added or hydrogen atoms are removed, this reaction will be oxidation reaction type. When we heat copper in the presence of air it becomes black due to the formation of other elements.

Complete answer:
We have to remember that when copper is heated in the presence of air that is oxygen, it converts itself into copper oxide and the color of the copper powder turns black due to the formation of its oxide.
On heating copper in china dish, it turns black as copper oxide is formed the equation can be represented below:
\[2Cu + {O_2} \to 2CuO\]
We must have to know that a chemical equation is said to be balanced if the number of moles is the same for reactants and products. This chemical equation is the balanced equation for this reaction as the number of moles in the left hand side is equal to the number of moles in the right hand side for each element involved in a chemical reaction. The copper oxide so formed is black in color and the oxidation state of copper is \[ + 2\].

Note:
We must have to remember that when copper is heated in china dish in presence of air, copper oxide is formed and this is an oxidation reaction, but also copper can reduced itself into its metal , this process is known as reduction and when both these processes takes place simultaneously these reactions are termed as redox reaction.