Question

A student designs an experiment to test substances X,Y,and Z, to determine which one is a catalyst for the reaction: A+B ® C. Only one of the unknown substances is a catalyst, and the others are nonreactive with A, B, or C. When 10 mL of A is added to 10 mL of B the reaction takes twenty seconds. Bubbles form when the product C is created. The student prepares three test tubes, each containing both reactants A and B. She adds unknowns X, Y, and Z to test tubes 1, 2, and 3, respectively. She then times the reaction in each test tube from the point when the unknown is added until bubbling stops. Which one contains the catalyst?

Answer 1

The test tube that first stops in bubbling or the production of a gas is the tube that contains the catalyst since the reaction ended faster than the others. A catalyst is known to speed up a reaction so it must the situation aforementioned is the answer.