CBSE Class 10 Science
Question 28 of 28
Chemical Reactions and Equations — Question 3
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Question Question 3
Identify the substances that are oxidised and the substances that are reduced in the following reactions.
(i) 4Na (s) + O2 (g) ⟶ 2Na2O (s)
(ii) CuO (s) + H2 (g) ⟶ Cu (s) + H2O (l)
(i) 4Na (s) + O2 (g) ⟶ 2Na2O (s)
- Sodium (Na) is oxidised to Na2O as it gains oxygen.
- Oxygen (O2) is reduced to Na2O as one atom of oxygen is removed from O2.
(ii) CuO (s) + H2 (g) ⟶ Cu (s) + H2O (l)
- Copper oxide (CuO) is reduced to copper (Cu) as oxygen is lost.
- Hydrogen (H2) is oxidised to water as it gains oxygen.