7.4 Endo and Exothermic Reactions

Energy and Chemical Reactions

The nature of endothermic and exothermic reactions. Duration: 11:44.

Chemical Kinetics

How fast a chemical reaction occurs depends much upon how fast the reactant molecules are moving. Duration: 13:52.

How Catalysts Work

A third way to increase the rate of a chemical reaction is to add a catalyst, which is a chemical that may participate in the chemical reaction but is not consumed by the chemical reaction. The catalyst works by lowering the energy of activation. Duration: 7:49.

Catalysts Are Not Consumed

This video lesson is pretty much a review of the previous video lesson. Only a few new concepts are introduced. This includes an explanation for how a catalyst transforms the energy of activation for a reaction. Biological catalysts, called enzymes, are also discussed. Duration: 4:37.