Question

class 10 science question

please answer​

Answer 1

Answer:

When the “copper powder” is heated in a ‘china dish’, the copper powder surface becomes coated with “black colour substance” due to the formation of ‘copper oxide’ by surface oxidation.

EXPLANATION:

Copper reacts with oxygen in the air upon heating and forms copper oxide. The black colour is due to the formation of this copper (II) oxide.

The copper oxide thus formed can be reduced to its basic metal form by reducing it with hydrogen or carbon monoxide.

The equation of ‘copper (II) oxide’ formation is:

$</p><p>\bold{2 C u(s)+O_{2}(g) \rightarrow 2 C u O(s)}2Cu(s)+O </p><p>2$

Answer 2

Answer:

$\huge\underline\mathtt\purple{Answer:-}$

Explanation:

(A) The 1 symbol represent Copper powder

and the 2 symbol represent the China dish

(B) It's shows the oxidation reaction I which the copper gets oxidized to copper oxide.

(C) Balanced chemical equations

CuO + H↓2 ------------- Cu + H↓2O

In this reaction Copper metal is heated in air , it gets oxidised to form copper oxide. This reaction can be reserved by passing hydrogen gas over heated copper oxide to get back copper metal

(D) Thus, if hydrogen gas is passed over heated copper oxide , then the black copper oxide is reduced and red - brown copper metal is obtained

CuO + H2. →. Cu + H2O

(hydrogen)

( copper oxide)

In this reaction , copper oxide is reduced to copper metal whereas hydrogen is oxidised to water.

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