Speed and Energy of Collision

Designing an Experiment Controlling the rate of a reaction is common in your everyday experience. Consider two of the major appliances in your kitchen a refrigerator slows down chemical processes that cause food to spoil and an oven speeds up chemical processes that cause foods to cook. Petroleum and natural gases require a spark to run your car s engine and heat your home. 

According to collision theory, reactants must collide with enough energy in order to react. Recall from the kinetic-molecular theory that mass and velocity determine the kinetic energy of a parti- 

In an exothermic reaction, molecules collide with enough energy to overcome the activation energy barrier, form an activated complex, then release energy and form products at a lower energy level. 

In the reverse endothermic reaction, the reactant molecules lying at a low energy level must absorb energy to overcome the activation energy barrier and form high-energy products. 

To investigate the relationship between spontaneity and reaction rate, consider the following gas-phase reaction between hydrogen and oxygen. 

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