Question

Explain pseudo first order reaction with examples ?

Answer 1

Hey there,

The chemical reaction that appears to be of higher order but it's actually first order reaction. so, as the name suggests (Pseudo : False) is known as Pseudo First order reaction.


C12H22O11+ H2O -----> Glucose(C6H12O6) + Fructose(C6H12O6)

Rate = k (C12H22O11)¹

order = 1+0 = 1

Answer 2

Pseudo First Order Reaction

Reactions with appears to be higher order but actually follow lower order kinetics (first order) are known as pseudo first order reaction.

Examples for Pseudo First Order Reaction:

1) Hydrolysis of sucrose

C₁₂ H₂₂ O₁₁ + H₂O ------------ C₆ H₁₂ O₆ + C₆ H₁₂ O₆

Rate = k [C₁₂ H₂₂ O₁₁]¹ [H₂O]⁰

This reaction appears to be second order but is first order, since water does not have any effect on rate.

Similarly, Hydrolysis of Ester also seems to be second order but water (H₂O) does not have any effect on rate so it is an example for pseudo first order reaction