Which among the following is (are) double displacement reaction(s)?

(i) Pb + CuCl2 PbCl2 + Cu


(ii) Na2SO4 + BaCl2 BaSO4 + 2NaCl


(iii) C + O2 CO2


(iv) CH4 + 2O2 CO2 + 2H2O

The reaction (i) is a type of displacement reaction as Pb displaces Cu and form a new compound PbCl2


The reaction (ii) is a type of double displacement reaction in which exchange of ions takes place.


The reaction (iii) is a type of combination reaction in which carbon and oxygen are combined together to form a single product that is CO2.


The reaction (iv) is a type of exothermic reaction as the burning of


natural gas (CH4) releases a large amount of energy.

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