Which among the following reactions is an example of pseudo first order reaction ?

Question

Which among the following reactions is an example of pseudo first order reaction ? (A) Inversion of cane sugar (B) Decomposition of H2O2 (C) Conversion of cyclopropane to propene (D) Decomposition of N2 O5

Tardigrade Admin · Accepted Answer

Inversion of cane sugar is an example of pseudo first-order reaction as water is present in large excess. Hence,

[H_{2} O]

remains constant and does not appear in the rate law expression.

C_{12} H_{22} O_{11} + H_{2} O \to C_{6} H_{12} O_{6}

(glucose )

+ C_{6} H_{12} O_{6}

(fructose )
Another example is the hydrolysis of methyl acetate.
The following are the examples of first-order reaction.
(B) Decomposition of

H_{2} O_{2}

(C) Conversion of cyclopropane to propene
(D) Decomposition of

N_{2} O_{5}

Q. Which among the following reactions is an example of pseudo first order reaction ?

Inversion of cane sugar

Decomposition of H2​O2​

Conversion of cyclopropane to propene

Decomposition of N2​O5​

Decomposition of $H_{2} O_{2}$

Decomposition of $N_{2} O_{5}$