MP NEET PG 2025 Round 1 Allotment: Counselling Revised Merit List

Elementary and Complex Reactions MCQ - Practice Questions with Answers

Edited By admin | Updated on Sep 25, 2023 25:23 PM | #NEET

Syllabus

Quick Facts

9 Questions around this concept.

Solve by difficulty

EASY

for a reaction with molecularity is $\mathrm{x}$ , then what will rate low equation of the reaction:

$\mathrm{Rate =k(A)}$

$\mathrm{Rate =k(A)^{x}}$

$\mathrm{Rate =k(A)^{2}}$

$\mathrm{Rate =k}$

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Concepts Covered - 2

Complex Reaction

Complex reactions are those reactions when a sequence of elementary reactions or single-step reactions gives us the products. Since the complex reactions occur in multiple steps thus, molecularity for such reactions cannot be determined. It can only be determined for elementary reactions.
For example:

$\mathrm{NO_{2}\: +\: CO\: \rightarrow \: NO\: +\: CO_{2}}$

The rate of the reaction is given experimentally as follows:

$\mathrm{rate\: =\: k[NO_{2}]^{2}}$

Now, clearly the order of this reaction is 2 but since it is a complex reaction, thus the molecularity of this reaction cannot be determined.

NOTE: For any complex or elementary reaction, it has been found that:

$\mathrm{Molecularity\: \leq\: 3 }$

Because the probability of simultaneous and effective collision of three molecules is very low. Thus, termolecular or higher molecularity reaction is rarely observed.

Order of Reaction vs Molecularity

Difference between Order of Reaction and Molecularity

Order of Reaction	Molecularity
Experimentally determined	Theoretically determined
Defined for elementary as well as complex	Defined only for elementary reactions
Can be -ve, 0, +ve or fractional	Always a positive integer
Can be greater than 3	Always less than or equal to 3