Collision theory chemical kinetics class 12th

 Collision Theory  

In each reaction there are two types of reactant molecule: 

1. Active molecule 
2. Passive molecule.

1.Active Molecule : Active molecule show effective collision they can achieve their energy level up to a certain limit barrier which is known as threshold energy level. 

2. Passive Molecule: Passive molecule cannot effective collision because there energy level cannot reach up to threshold energy level. 

Due to effective collision between active reactant molecule product formation take place it means that passion molecule are not responsible for product formation. 

Catalyst 

Catalyst are those chemical  which can effect the rate of reaction depending upon its nature without participating in chemical reaction. 

Functions of Catalyst  

There are two main functions of catalyst:

Catalyst provider surface for react and molecule to reactant on over it and I will to form product and finally left it in the region is that the surface of any catalyst is porus in nature. It is also a reason why catalyst in powered form so it's better action. 

Defending upon the nature of catalyst that is catalyst increase the rate of reaction where is negative the rate of reaction. The reason is that up positive catalyst can decrease the level threshold energy (activation energy barrier) that's why more and more react and molecule can jump and cross these energy level and become active molecule their number of effective collision become increase product formation will become easy and fast that's rate of reaction increase. 

Where is in case of negative catalyst increase the threshold energy level (activation energy barrier) that's why less reactant molecule can jump and cross these energy level and number of active collision becoming decrease their effective collision become also in decrease product formation become slow that's why the rate of reaction decrease.