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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. How can the student identify the catalyst? The test tube that stops bubbling first contains the catalyst. The test tube that produces the most bubbles contains the catalyst. The test tube that bubbles the longest contains the catalyst. The test tube that does not bubble contains the catalyst.

Respuesta :

The substance may be identified because the test tube that stops bubbling first contains the catalyst
The function of a catalyst is to reduce the activation energy of a  reaction and increase the rate of reaction. This means that in this particular reaction, bubbling will begin and end in a shorter period of time due to the increased rate of reaction.