Statement I: Molecularity of a reaction cannot be more than three

Statement II: Probability of simultaneous collision between more than three particles is very less.

Statement I and statement II are correct and statement II is correct explanation of statement I

The correct answer is option 1. Statement I and statement II are correct and statement II is correct explanation of statement I.

Statement I: Molecularity of a reaction cannot be more than three.

This statement is correct. The molecularity of a reaction refers to the number of reactant molecules that come together and collide simultaneously to produce products in an elementary step. Due to steric hindrance (the physical repulsion between atoms) and geometric factors, it's highly improbable for more than three molecules to collide effectively and react in a single step.

Statement II: Probability of simultaneous collision between more than three particles is very less.

This statement is also correct. The probability of simultaneous collisions between more than three particles is very low. As the number of particles increases, the chances of them all being in the correct orientation and having sufficient energy to react at the same time become statistically less likely.

Relationship between the statements:

While both statements are true, Statement II doesn't explain Statement I. The limitation on molecularity arises not only from the difficulty of a multi-particle collision but also from the reaction mechanism itself.

Elementary reactions are defined as reactions that occur in a single step. If a reaction requires more than three molecules to come together, it likely proceeds through a multi-step mechanism involving multiple elementary steps. The overall molecularity would then be undefined.

In essence:

Statement I is a fundamental principle about elementary reactions.

Statement II is a general probability statement that supports the improbability of high molecularity reactions but isn't the sole reason behind the limitation.