Question

A double displacement reaction involves the breaking of old bonds and the formation of new bonds. Do you agree? Justify your answer with an example.

Answer 1

Double decomposition reaction:

A chemical reaction in which two ionic compounds in the solution react to form two other compounds by the mutual exchange of ions is called a double decomposition reaction.

It is also called a partner exchange reaction.

An example of double decomposition would be,

$\underset{(Sodiumhydroxide)}{\underbrace{NaOH\left(aq\right)}}+\underset{\left(Hydrochloricacid\right)}{\underbrace{HCl\left(aq\right)}}\to \underset{(SodiumChloride)}{\underbrace{NaCl\left(aq\right)}}+\underset{\left(Water\right)}{\underbrace{H_{2}O\left(l\right)}}$

Here, there are two ionic compounds Sodium hydroxide $\left(NaOH\right)$ and Hydrochloric acid $\left(HCl\right)$ reacting to form a salt Sodium chloride $\left(NaCl\right)$ and Water $\left(H_{2}O\right)$. This is also an example of a Neutralization reaction.

The ionic bond between Sodium ion $\left(N{a}^{+}\right)$ and hydroxide ion $\left(O{H}^{-}\right)$ is first broken, again the polar covalent bond of $HCl$gets dissociated into a Hydrogen ion $\left(H^{+}\right)$ and Chloride ion

Then on the product side, the Cation $\left(N{a}^{+}\right)$gets paired with the anion $\left(C{l}^{-}\right)$ to form $NaCl$, and the same is happening to form water.

Yes, a double displacement reaction involves the breaking of old bonds and the formation of new bonds.