Video Transcript
What name is given to a catalyst
that can slow down a chemical reaction? (A) Block catalyst, (B) negative
catalyst, (C) stop catalyst, (D) slow catalyst, or (E) decelerating catalyst.
A catalyst is a substance that
changes the rate of a reaction without undergoing a permanent chemical change. Lactase is an example of a
biological catalyst, also called an enzyme. Lactose is a large sugar molecule
that is difficult for our body to digest. Breaking down lactose into smaller
sugars that our body can more easily digest is a slow process. Luckily, lactase is a catalyst that
can bind with lactose and quickly break it into smaller sugars. Following the reaction, lactase
looks the same as it did before the reaction. So, the catalyst did not undergo a
permanent chemical change and can be used again to break more lactose molecules.
Catalysts like lactase, which speed
up a chemical reaction, are known as positive catalysts. But there are also catalysts that
slow down the rate of a reaction. These are called negative
catalysts. Negative catalysts are frequently
added to drugstore hydrogen peroxide to slow down its decomposition. So, what name is given to a
catalyst that can slow down a chemical reaction? The answer is (B) negative
catalyst.
