Which of the following is an example of pseudo unimolecular reaction ?

Options

A. `CH_(3)COOCH_(3)+H_(2)Ooverset(H^(+))(to)CH_(3)COOH+CH_(3)OH`
B. `CH_(3)COOCH_(3)+H_(2)Ooverset(H^(-))(to)CH_(3)COOH+CH_(3)OH`
C. `2FeCl_(3)+SnCl_(2)toSnCl_(4)+2FeCl_(2)`
D. `NaOH+HCl to NaCl+H_(2)O`

Answer

A

Explanation

When in any chemical reaction, one of the reactant is present in large excess, then the second order reaction becomes first order reaction and is known as pseudo unimolecular reaction e.g.,
`CH_(3)COOCH_(3)+H_(2)Ooverset(H^(+))(to)CH_(3)COOH+CH_(3)OH`
in this reaction molecularity is 2 but order of reaction is found to be first order experimentally, so it is an example of pseudo unimolecular reaction .