Question

What are elementary reactions involving two reactants called?

Answer 1

Elementary reactions

• A single-step reaction is known as an elementary reaction.
• The elementary reaction is divided into unimolecular, bimolecular, and termolecular.

Bimolecular reaction

• The elementary reactions in which two reactants participate are called bimolecular reactions.
• An example of a bimolecular reaction is as follows:-

$$\begin{gathered} \mathrm{A}+\mathrm{A}\to \mathrm{P} \\ \mathrm{A}+\mathrm{B}\to \mathrm{P} \end{gathered}$$

• In the first reaction, two reactants(A, A) are involved and in the second reaction, two reactants (A, B) are involved in the formation of product(P). So, this reaction is a bimolecular reaction.
• ${\mathrm{SN}}_2$ is a bimolecular reaction whose rate depends on the concentration of alkyl halide and the concentration of nucleophile,

Hence, bimolecular reactions are elementary reactions involving two reactants.