Lesson 6.05. Rate and Collision Theory. Introduction. Have you ever driven a bumper car? The point of driving a bumper car, at least for most people, is to collide with as many other cars as possible.
Rate and Collision Theory
Keep the relationship between amount, speed, and collisions in mind as you continue into the lesson to discuss the rates of chemical reactions.
After completing this lesson, you will be able to:
When chemists plan a reaction, they ask questions like:
The rate of a reaction is usually measured in one of two ways:
A successful collision is one that results in making the product(s).
Two factors must be true for a reaction to be “successful”:
The hydrogen chloride molecule is correctly oriented to the double bond in the ethene molecule.
These are all incorrect orientations
These will not be successful in producing the new product; the two reactants will just “bounce” off of each other.
For many reactions involving liquids or gases, increasing the concentration of the reactants increases the rate of reaction
Be careful: doubling the concentration of one of the reactants doesn’t mean you will double the rate of the reaction.
The amount by which an increase in concentration increases the rate of a reaction depends on many different properties of the reaction.
This direct relationship between temperature and rate is due to two reasons:
EXAMPLE: Enzymes. In your body, living cells can only survive within a narrow temperature range.
Raising the temperature within the cells to speed up the necessary chemical reactions would result in damage to the very cells that the reactions support.
Some other ways to increase the rate of a reaction that you have already learned about include:
You should now be able to:
Please review this lesson again if you need to