Question

Are Double Displacement Reactions Redox ?

Answer 1

Definition of double displacement reaction:

1. A chemical reaction in which ions get exchanged between two reactants to form new compounds is called a double displacement reaction.
2. Example:$\mathrm{Pb}{\left({\mathrm{NO}}_3\right)}_2\left(\mathrm{aq}\right)+\hspace{0.17em}2\mathrm{KI}\left(\mathrm{aq}\right)\to {\mathrm{PbI}}_2\left(\mathrm{s}\right)+2{\mathrm{KNO}}_3\left(\mathrm{aq}\right)$

Definition of redox reaction:

1. Redox(reduction-oxidation) reactions are defined as chemical reactions that involve a change in the oxidation state of the reacting species.
2. Reduction involves the gain of electrons by the substrate thus leading to a decrease in the oxidation state.
3. Oxidation involves the loss of electrons by the substrate thus leading to an increase in the oxidation state.
4. Example: ${\mathrm{H}}_2+\hspace{0.17em}{\mathrm{F}}_2\to 2\mathrm{HF}$

Explanation:

1. In the case of double displacement reactions, none of the reactants undergo either oxidation or reduction rather there occurs only an exchange of ions between the two reactants.
2. So, double displacement reactions are not redox reactions.