Question

Explain what are double displacement reactions with an example?

Answer 1

Those reactions in which two compounds react by an exchange of ions to form new compounds are called double displacement reactions.

General representation of a double displacement reaction:

AB + CD 🡪 AD + CB

For example,

$\mathrm{NaSO}4\left(\mathrm{aq}\right)+\mathrm{BaCl}2\left(\mathrm{aq}\right)🡪\mathrm{BaSO}4\left(s\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)$

NaSO4 (aq)	Sodium sulphate
BaCl2 (aq)	Barium chloride
BaSO4 (s)	Barium sulphate
2NaCl (aq)	sodium chloride