Question

The process which is catalysed by one of the products is called :
A. Acid-base catalysis
B. Autocatalysis
C. Negative catalysis
D. Homogeneous catalysis

Answer 1

Hint: Catalyst makes a reaction hurry up and doesn't get used up in the process. This process is called catalysis. When one of the products of a reaction behaves as a catalyst as well, then it is known as autocatalysis.

Complete Step by Step Answer:
A reaction usually happens at much quicker than its initial rate after the addition of a catalyst.
The catalyst continues to be as it was in terms of the chemical composition and mass when the reaction gets completed.
The amount of the catalyst at the end of the reaction was found to be the exact as the amount taken at the beginning of the reaction. So, it does not get used up during the reaction.
Its physical state like size, colour, etc., may change.
Hydrolysis of ester results in carboxylic acid and alcohol. Carboxylic acid functions as a catalyst for the reaction.
When one of the products of a reaction functions as a catalyst it is known as autocatalysis. The catalyst is known as an autocatalyst.
For example,
The rate of oxidation of oxalic acid in presence of acidified potassium permanganate gains as the reaction proceeds.
This is due to the presence of \[{\rm{M}}{{\rm{n}}^{{\rm{2 + }}}}\]
ions which are formed during the reaction. Thus, \[{\rm{M}}{{\rm{n}}^{{\rm{2 + }}}}\]
ions work as auto-catalyst.

The reaction happens as follows:
\[{\rm{2KMn}}{{\rm{O}}_{\rm{4}}}{\rm{ + 3}}{{\rm{H}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}{\rm{ + 5}}{\left( {{\rm{COOH}}} \right)_{\rm{2}}} \to {{\rm{K}}_{\rm{2}}}{\rm{S}}{{\rm{O}}_{\rm{4}}}{\rm{ + 2MnS}}{{\rm{O}}_{\rm{4}}}{\rm{ + 8}}{{\rm{H}}_{\rm{2}}}{\rm{O + 10C}}{{\rm{O}}_{\rm{2}}}\]
So, the process which is catalysed by one of the products is called autocatalysis.
So, option B is correct.

Note: A reaction usually happens at much quicker than its initial rate after the addition of a catalyst. The amount of the catalyst at the end of the reaction was found to be the exact as the amount taken at the beginning of the reaction. So, it does not get used up during the reaction. In autocatalysis, one of the products functions as a catalyst. Firstly, the reaction is unhurried but with the formation of the products the reaction rate upsurges.