Question

Explain the functioning of Inhibitor.

Answer 1

Activation energy

• It is described as the minimum amount of energy needed to activate or energize molecules or atoms so that they can undergo a chemical reaction.
• Positive catalyst decreases the energy barrier, so, the activation energy is low, whereas in negative catalyst activation energy will be high.

Fig: Diagram of Activation energy.(negative value shows increase in Activation and energy and positive value shows decrease in activation energy)

• Negative catalyst increases activation energy by taking a longer alternative path and hence, slows down the reaction.

Functioning of Inhibitor

Inhibitors are chemical compounds that slow down the reaction. They sometimes even stop the reaction. They work exactly opposite of catalysts.

Catalyst and Inhibitors

• Catalyst enhances the rate of reaction without participating in the reaction, whereas Inhibitors stop or slow down the reaction.
• Inhibitors reduce the activity of catalysts. Therefore, they are also called “ negative catalysts”.
• Catalyst decreases the activation energy of the reaction, whereas inhibitors tends to increase it.
• Example of catalyst: In the cracking of petroleum zeolites are used as a catalyst.
• Example of inhibitor: Penicillin acts as an inhibitor, it blocks the active site of the enzyme.

Hence, Inhibitors work as the negative catalyst they either slow down the reaction or stop them completely.