Q30 of 152 Page 46

What is a decomposition reaction? Give an example of a decomposition reaction. Describe an activity to illustrate such a reaction by heating.

When in a reaction compound splits two or more simpler substance the reaction is called decomposition reaction.


Cacium carbonate decomposes when heated into calcium oxide and carbon dioxide.


Activity: Potassium chlorate decomposes to give Potassium chloride and oxygen, when heated in presence of catalyst manganese dioxide.



Potassium Chlorate a single compound, is splitting up into two simpler substances, potassium Chloride and oxygen. This decomposition reaction is used to prepare oxygen gas in laboratory.



More from this chapter

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28 (a) Give an example of an oxidation reaction.

(b) Is oxidation an exothermic or an endothermic reaction?


(c) Explain, by giving an example, how oxidation and reduction proceed side by side.

 29 (a) What is the colour of ferrous sulphate crystals? How does this colour change after heating?

(b) Name the product formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?

 31 Zinc oxide reacts with carbon, on heating, to form zinc metal and carbon monoxide. Write a balanced chemical equation agent, and

(i) Oxidising agent


(ii) reducing agent, in this reaction.

 32 Give one example of a oxidation -reduction reaction which is also:

(a) a combination reaction


(b) a displacement reaction