# What is order and molecularity of reaction?

## What is order and molecularity of reaction?

The terms order and molecularity are common in chemical kinetics. Hint: Order of reaction is the sum of the concentration term on which the rate of reaction actually depends and while molecularity is the number of atoms, ions or molecules that must collide to result into a chemical reaction.

How do you determine molecularity?

The molecularity of the chemical reaction is equal to the sum of the stochiometric coefficients of the reactants in the chemical equation of the reaction. It is also defined as the number of reactant molecules taking part in a single step of the reaction.

What is molecularity of a reaction Class 12?

MOLECULARITY OF REACTION: The minimum number of reacting particles that take part in a rate determining step to form product is called molecularity of reaction.

### Why molecularity is not more than 3?

Molecularity cannot be greater than three because more than three molecules may not mutually collide with each other effectively.

Is molecularity same as order?

Solution: Order and molecularity can be same only for elementary reaction and it is different for complex reaction. Order is determined experimentally and molecularity is the sum of the stoichiometric coefficient of rate-determining elementary step. Hence, Option “E” is the correct answer.

How does molecularity affect rate of reaction?

Molecularity gives the number of molecules or ions that participate in the rate-determining (slowest) step of a reaction. If a reaction is unimolecular, only a single species is involved in the reactants side of the rate-determining step. If a reaction is bimolecular, the rate depends on two species.

## What is the value of molecularity?

Four is the answer The value of molecularity cannot be zero, negative, fractional, infinite, and imaginary. So, it can only be positive integer. The value of molecularity cannot be greater than 3 as more than three molecules may not mutually collide or come closer during the course of the chemical reaction.

What is the meaning of molecularity?

Molecularity in chemistry is the number of molecules that come together to react in an elementary (single-step) reaction and is equal to the sum of stoichiometric coefficients of reactants in the elementary reaction with effective collision (sufficient energy) and correct orientation.

Why are high molecularity reactions rare?

Reactions of higher molecularity (molecularity > 3) are rare. This is because a reaction takes place by collision between reactant molecules and as number of reactant molecules i.e. molecularity increases the chance of their coming together and colliding simultaneously decreases.

### Is molecularity defined for a complex reaction?

Molecularity has no meaning for a complex reaction.

Can molecularity be determined experimentally?

Assertion : Molecularity of a reaction cannot be determined experimentally. Reason : Molecularity is assigned to the reactions on the basis of mechanism.

What are the steps in a chemical reaction?

A reaction step of a chemical reaction is defined as: “An elementary reaction, constituting one of the stages of a stepwise reaction in which a reaction intermediate (or, for the first step, the reactants) is converted into the next reaction intermediate (or, for the last step, the products) in the sequence of intermediates between reactants and

## Do all chemical reactions occur at the same rate?

Not all chemical reactions occur at the same rate. Some happen very quickly like explosions, while others can take a long time, like metal rusting. The speed that the reactants turn into products is called the reaction rate. The reaction rate can be changed by adding energy such as heat, sunlight, or electricity.

What is an unimolecular reaction?

A unimolecular reaction is an elementary reaction in which the rearrangement of a single molecule produces one or more molecules of product.

What is the role of catalyst in a chemical reaction?

Role of a catalysts in chemical reactions: Catalyst is a substance, usually used in small amounts relative to the reactants, that modifies and increases the rate of a reaction without being consumed in the process.