Qualitative Kinetics - Ways to Influence the Rate of a Reaction

Ways to Influence the Rate of a Reaction



Five of the most common ways to influence the rate of reaction can be explained using collision theory. They are:

1. changing the nature of the reactants

2. changing the concentration of one or more of the reactants

3. changing the temperature at which a reaction is performed

4. changing the surface area of a solid reactant

5. adding a catalyst

In order to experimentally determine the effect of each of these changes, it is necessary to perform at least two experiments in which all but one variable is held constant and then compare the resulting reaction rates.

The rate of a reaction can be determined by measuring the rate at which the reactants disappear or the rate at which the products form. The process is simple if one of the products is a gas. The faster the gas is produced, the faster the rate of reaction. Consider the example of hydrogen peroxide decomposition before reading further. Similar comparisons can be made for other reactions in which one of the products or reactants is colored. In this case, the rate of color appearance or disappearance gives us information about the reaction rate.


This completes the background material, proceed to the prelab.


introduction background prelab experiment postlab