Question

Give one example of a double decomposition reaction.

Answer 1

1. Double decomposition reaction:

Reaction in which both the reactants interchange their ions and form two new compounds.

$\mathrm{AB}+\mathrm{CD}\to \mathrm{AD}+\mathrm{CB}$
Here $\mathrm{A}$ and $\mathrm{C}$ are interchanging their place.

2. Example:

a. When an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride white precipitate of barium sulphate is formed.
b. Reaction:
${\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)+{\mathrm{BaCl}}_2\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{s}\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)$
Sodium sulphate Barium chloride Barium sulphate Sodium chloride
c. In this $\mathrm{Na}$and $\mathrm{Ba}$ are interchanging their place it is a double decomposition reaction.