Question Video: Determining How a Catalyst Affects the Energy Profile of a Chemical Reaction Science

The diagram shows the energy needed for a chemical reaction to occur. How does a positive catalyst affect this energy? [A] It will increase it. [B] It will not affect it. [C] It will decrease it.

02:01

Video Transcript

The diagram below shows the energy needed for a chemical reaction to occur. How does a positive catalyst affect this energy? (A) It will increase it, (B) it will not affect it, or (C) it will decrease it.

The diagram provided is an energy level diagram. It shows the relative energy of the reactants and products. It also shows the amount of energy that must be supplied in order for a reaction to occur. The question asks how a positive catalyst would affect this amount of energy.

A positive catalyst is a substance that increases the rate of a reaction without undergoing a permanent chemical change. Lactase is an example of a positive catalyst. Lactase serves an important role in biological systems. Its job is to help break down lactose, a large sugar molecule that is difficult for our bodies to digest. Lactose could break into smaller sugars on its own, but this reaction is very slow because it requires a large amount of energy. That’s where lactase comes in. Lactose binds to lactase, which then breaks the large lactose molecule into smaller sugars. The reaction using lactase, a positive catalyst, is much faster. This is because less energy is required for the reaction to occur.

On an energy level diagram, the energy at which a reaction occurs will be lower when a positive catalyst is used. This means that when using a positive catalyst, the energy needed for a reaction to occur will be lower. So, how does a positive catalyst affect the energy needed for a reaction to occur? The answer is (C). It will decrease it.

Nagwa uses cookies to ensure you get the best experience on our website. Learn more about our Privacy Policy.