Mechanism of Chemical Reaction Chemistry Notes
Mechanism of a Chemical Reaction :
→ As we know that complex reactions do not take place in one step. These reactions take place in many steps. The step in these reactions, which takes place at slowest rate, is called rate determining step of complete reaction. So, these molecules are necessarily used in slowest step at which the rate of reaction depends. With the help of these various steps, we can determine the mechanism of chemical reactions.
Here, step-I is rate determining step in above mechanism and order of reaction is 1.
→ Table 4.1: Differences between Molecularity and Order of Reaction
|Molecularity of Reaction
|Order of Reaction
|The molecularity of reaction can be determined only fort one step.
|Order of reaction can be determined for complete reaction.
|This is a theoretical vaiuer which can be determined on the basis of reaction.
|This is an experimental value which can not be determined on the basis of reaction.
|Its value can not be zero.
|Its value can be zero.
|Its value is always a wholel number.
|Its value. can be whole number as well as fractional.
|Its value is always positive.
|Its value may be positive as well as negative.
|The molecularity of reaction projects the mechanism of reaction.
|The order of reaction does not project the mechanism of reaction.