CHEMISTRY GUIDE

Topic 2.2 RATES OF REACTION Some reactions take place instantly, but most are much slower and it is possible to measure how long these reactions take to reach a certain stage. As a chemical reaction proceeds, the concentration of the reactants decreases and the concentration of the products increases. The decrease in the concentration of reactants per unit time, or the increase in the concentration of products per unit time, is known as the rate of reaction . The study of rates of reaction is known as kinetics . SIMPLE COLLISION THEORY How do chemical reactions take place? Substances in the liquid, aqueous and gaseous phase consist of particles in rapid and constant motion. The rate of a chemical reaction depends on three factors: 1.    Collision frequency If a chemical reaction is to take place between two particles, they must first collide. The number of col...