I tried to make this tutorial as straightforward as possible. The bolded words are terms that you need to know. While standard test do not require you to memorize the equations, knowing them will only help you. With the understanding of the speed and the process of a reaction, chemists can facilitate reactions to their needs.
Reaction rate is simply the change in the amount of product or reactant over time.
The amount is measured in molarity while the change in time is in seconds. A is the reactant or product, and the enclosed brackets stands for the molarity. Think of the reaction rate as the slope of the concentration vs. time graph. The reaction rate of the reactant is always negative because the reactant is decreasing to form the product. The reaction rate of the product is always positive because the product is being formed.