Catalysts

[Mike Vinci 2B]

Could someone explain why a catalyst is not consumed in a reaction, and how it can effect the reaction while also being reused over time. Also, do certain reactions require specific catalysts, or can catalysts effect many different types of catalysts?

Mike.

[SPandya1F]

Catalysts are not reactants; they just lower the activation energy. They are substances added to a chemical reaction to speed up the reaction rate without being consumed. Catalysts are not in the overall chemical reaction. For example, enzymes are catalyst in biochemical reactions.

[Harjas Sabharwal 1G]

A catalyst just alters the environment or makes it more likely that a reaction will occur. Effectively, it reduces the activation energy "hill" so that the reactants can react with each other. This can be shown by enzymes. Enzymes bring their substrates together and then alter their formation to make them more likely to react and thus start the reaction.

[Jennifer Ho 1K]

Catalysts speed up the reaction rate by putting stress on the bonds to be broken in the reaction, allowing them to be broken more easily, thus lowering the activation energy. They are not consumed in the overall reaction, but they may be consumed in the reaction mechanism, reforming later on in the mechanism.