A catalyst acts to lower the energy of activation for a chemical reaction. By lowering the activation energy, the reaction is able to proceed using less energy and more quickly. While the rate doesn't change with the use of a catalyst, the lowered activation energy allows reactants to react easier to form products, speeding up the reaction. The catalyst is used in a chemical reaction but is reformed in its original state before the end of the reaction.

Use the following hotspot to explore what happens to the energy of activation when a catalyst is present.




learning activity Scroll your mouse over the energy diagram to explore how a catalyst changes the reaction’s energy.
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From a biological standpoint, catalysts allow a reaction to occur on a shorter timescale. Here is a video explaining some of the important functions catalyses play.





Heres another approach at explaining what catalysts do.




Use the following simulation to explore the rate of chemical reactions and how it is affected by changes in these variables. First try the simulation out with only changing one of the factors, then after you've demonstrated its affects, try combining the factors.


Reactions & Rates
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Quiz yourself on rates of reaction.


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