Question

Explain the following types of chemical reactions giving two examples for each of them.

(a) Combination reaction

(b) Decomposition reaction

Answer 1

A combination reaction is a reaction in which two or more substances combine to form a single substance.

A+B→AB

E.g. (i) When iron and sulphur are heated together, they combine to form iron sulphide.

(ii)When carbon bums in oxygen to form a gaseous compound called carbon dioxide.


In a decomposition reaction, a compound breaks up due to the application of heat into two or more simple substances.

CaCO₃ when heated decomposes to calcium oxide and carbon dioxide.