Question

Which of the following is not a characteristic of a catalyst?

• A. A catalyst lowers the activation energy of a reaction
• B. A catalyst increases the speed of a reaction
• C. Only a small quantity of catalyst is needed in a chemical reaction
• D. A catalyst is used up during the reaction

Hint:

Remember: Catalyst \(\downarrow E_a\), \(\uparrow\) rate, and is regenerated — it’s not consumed.

Answer 1

The Correct Option is D

Step 1: Define a catalyst.
A catalyst speeds up a reaction by offering a different route with lower activation energy. It isn't permanently changed in the process.
Step 2: Verify each statement.
(1) True — Decreased \(E_a\) (see Arrhenius equation: \(k = A e^{-E_a/RT}\)).
(2) True — Rate increases because \(k\) is larger.
(3) True — Only small quantities are needed as the catalyst is regenerated (high turnover).
(4) False — A catalyst is not used up; its chemical composition remains unchanged.
Final Answer: \[ \boxed{\text{A catalyst is used up during the reaction}} \]