Question

A chemist finds that when platinum is added to a reaction, the reaction speeds up. He thinks the platinum may be acting as a catalyst. What measurement should the chemist make to determine whether it is a catalyst?
Measure the mass of the platinum before and after the reaction.
Measure the temperature of the solution before and after the reaction.
Measure the change in volume of the solution.
Measure the amount of gas released by the reaction.

Answer 1

Measure the mass of the platinum before and after the reaction 
as if it is acting as a catalyst the mass of platinum will remain unchanged as catalyst do not consume themselves in reaction  

Answer 2

Answer: Option (a) is the correct answer.

Explanation:

A substance that does not get consumed in a chemical reaction and helps in increasing rate of the reaction by lowering the activation energy is known as a catalyst.

Hence, when the chemist finds that reaction speeds up when platinum is added into the reaction then the chemist must calculate or measure the mass of platinum before and after the completion of reaction.

This is because if there occurs change in the mass of platinum then it means that platinum is not acting as a catalyst in the reaction.

Thus, we can conclude that chemist must measure the mass of the platinum to determine whether it is a catalyst.