Question

When hydrogen gas is passed through heated black-coloured metal oxide(X), X is reduced to a metal(Y) which is brown in colour. Identify X and Y and write the balanced reaction involved.

Answer 1

Given:-

Hydrogen gas is passed through metal oxide X, after which X is reduced to a metal Y which is brown in colour.

To identify:-

X and Y

Solution with equation:-

We know, that if X gets reduced to Y on reacting with H₂, then Y(whose oxide is X) is less reactive than H in the reactivity series.

The metal which is less reactive than H and whose oxide is black-coloured is obviously Copper.

So, the oxide X is Copper-oxide [copper(II) oxide].

So,

X - Copper(II) oxide or Cupric oxide or CuO

Y - Copper

The reaction is as follows:-

CuO(s) + H₂(g) → Cu(s) + H₂O(l)