What is the difference between double displacement and singe displacement reaction?

In Double displacement reaction, ion of two compound switch there places to form two new compounds.

NaCl(aq)+ AgNO3NaNO3 (aq)+AgCL(s)


In single displacement reaction in which more reactive element takes up the place of another element in a compound.


Zn (s)+CuSO4 (aq) ZnSO4 (aq)+ Cu(s)


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