Question

when the powder of a common metal is heated in an open china dish, its colour turns black.however when hydrogen is passed to the black hot substance so formed,it regains its orginal colour.name the metal initially taken in the powder form.write balanced chemical equations for both reactions
what type of chemical reaction takes place in each of the two given steps?
name the metal initially takes in the power form​

Answer 1

the metal initially takes in the power form​ is copper.

when the powder of a common metal is heated in an open china dish:

    2Cu+O₂------>2CuO

when hydrogen is passed to the black hot substance:

   CuO+H₂------>Cu+H₂O

Redox reaction took place in each of the two given steps.

the first reaction is a Combination reaction.

the second reaction is a Displacement reaction.