Question

The number of molecules involved in an elementary reaction is termed as ____

(a) Molecularity

(b) Order of reaction

(c) Unimolecular reaction

(d) Rate of reaction

The question was posed to me in class test.

The doubt is from Reaction Rates in section Basic Concepts of Chemical Reaction Engineering

Answer 1

Right choice is (a) Molecularity

To explain: Molecularity of an elementary reaction is the number of molecules of the reactant taking part in the reaction. Order of a reaction is the sum of the powers of the concentrations of all the reactants. Unimolecular reactions involve only one reactant. Rate of a reaction is the number of moles of the reactant component disappearing per unit volume per unit time.