Question

what happens when hydrogen gas is passed over the hot copper (ll)oxide

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Answer 1

The brown substance' X' is copper .When it is heated copper oxide is formed .

Hence compound 'Y' is copper oxide.

The reaction is as follows.It is a combination reaction.

2Cu + O2 -----> 2CuO

As during this reaction the copper(II) oxide is losing oxygen and is being reduced. The hydrogen is gaining oxygen and is being oxidised.In other words, one reactant gets oxidised while the other gets reduced.

Answer 2

Answer:

When hydrogen gas is passed over heated copper oxide, then the black copper oxide is reduced and brown copper metal is obtained.

CuO + H2 → Cu + H2O(water)

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