Pseudo Unimolecular Reactions Chemistry Notes
Pseudo Unimolecular Reactions :
The reactions whose molecularity is two or more but order of reaction is one, are called pseudo unimolecular reactions.
Example : Inversion of cane sugar
→ The order of above reaction is one but molecularity is two. The rate of this reaction depends on concentration of sugar only. Here, the amount of water is in excess. So. there is no measurable change in the concentration of H2O during the reaction. This reaction is called first order reaction.
Example : Acidic hydrolysis of ethyl Acetate
→ Here, H.O is also in excess, so there is no specific change in the concentration of water during completion of reaction. So, its concentration is taken as constant and rate of reaction depends only on the concentration of ethyl acetate. So. Rate = k [CH3COO2CH5]