Molecularity of reaction
Number of reactive molecules collide simultaneously and change into product is called molecularity of reaction.
2NH3→ N2 + 3H2 ,Molecularity=Co-efficient of reactant is 2, So molecularity of reaction= 2
Order of reaction
It is the sum total of Stoichiometry concept in the expression of rate law is called order of reaction .
xA + yB → pC + q D
A/c to rate law , Rate= K[A]x [B]y
Order of reaction=x+y
Difference between molecularity and Order of reaction
| Molecularity | Order of reaction |
| It is theoretical concept. | It is theoretical experimental concept. |
| It is number of reacting molecules participated in simultaneous collision and change into product. | It is the sum total of stoichiometric concept in the expression of rate law is called order of reaction . |
| It never be Zero. | It may be Zero |
| It never be in fraction. | It may be in fraction. |
| Example 2NH3→ N2 + 3H2 Molecularity=Co-efficient of reactant is 2,So molecularity of reaction= 2 | Rate= K[A]x [B]y Total concentration term=x+y, Order of reaction=x+y |
Order of reaction and Molecularity of reaction FAQ.
Q Molecularity of reaction may be zero yes or not.
Ans- No
Q Order of reaction may be experimental concept Yes or No
Ans- Yes
