Question

What happens when Hydrogen gas is added to Copper oxide?

Answer 1

We have to know that hydrogen is a chemical element having the atomic number one with symbol $'H'$. The standard atomic weight of hydrogen is equal to $1.008$. It is the lightest element which is present in the periodic table. The hydrogen is a non – metallic element with no odor and color. The copper oxide is a chemical element having formula, $CuO$. And it contains two elements which are copper and oxygen atoms. The copper oxide is widely used as a precursor.

Complete answer:
When Hydrogen is added to Copper oxide, there will occur the reduction of copper oxide to copper metal. Then the black copper oxide will become brown-colored copper metal. And the hydrogen gas undergoes the oxidation reaction to form water. Let’s see the reaction,
$CuO + {H_2}O \to Cu + {H_2}O$
The reduction process takes place by the loss of oxygen. Here, the copper oxide will lose the oxygen and it will be reduced to copper. And the oxidation is taken by gaining the oxygen atom. Therefore, there is a formation of water by the oxidation of hydrogen atoms. And the hydrogen acts as a reducing agent. Because, from copper oxide, it removes the oxygen. The oxidation and the reaction can be written as,
$CuO\xrightarrow{{reduction}}Cu$
${H_2}\xrightarrow{{oxidation}}{H_2}O$

Note:
This reaction is a redox reaction. Because, it takes place both oxidation and reduction reaction. The copper oxide acts as the oxidizing agent and hydrogen gas acts as the reducing agent. The copper oxide is usually black in colour. When it is reacted with hydrogen, it loses oxygen and there is a formation of copper metal which is black in colour.