Explain the following in terms of gain or loss of oxygen with two examples each. (a) Oxidation (b) Reduction
Answers
(a) Oxidation: A chemical reaction in which a substance gains oxygen is called oxidation. ... (b) Reduction: A chemical reaction in which a substance loses oxygen is calledreduction. ZnO + C → Zn + CO, ZnO isreduced to Zn. CuO + H2 → Cu + H2O, CuO is reduced to Cu.
Answer- The above question is from the chapter 'Redox Reactions'.
Given question: Explain the following in terms of gain or loss of oxygen with two examples each. (a) Oxidation (b) Reduction.
Answer: The word 'Redox' has been derived from 'Red' which means Reduction and 'ox' meaning Oxidation.
It suggests that Oxidation and Reduction reactions go hand in hand.
The process of reduction involves-
1. Removal of oxygen from a substance.
2. Addition of hydrogen to a substance.
3. Gain of electrons in a substance.
4. Gain of electropositive element in a substance.
5. Removal of electronegative element from a substance.
6. Decrease in the oxidation number of a substance.
The process of oxidation involves-
1. Addition of oxygen to a substance.
2. Removal of hydrogen from a substance.
3. Loss of electrons in a substance.
4. Removal of electropositive element from a substance.
5. Gain of electronegative element in a substance
6. Increase in the oxidation number of a substance.
Example:
ZnO + C → Zn + CO
Here, ZnO has been reduced as oxygen is removed from it.
C has been oxidised.
Fe₂O₃ + Al → Al₂O₃ + Fe
Here, Fe₂O₃ has been reduced as oxygen is removed from it.
Al has been oxidised.