Reaction Rates
Reaction rate is defined, simply, as the speed at which a reaction takes place. Reaction rates can be affected by several variables: (1) concentration, (2) surface area, (3) temperature, and (4) catalysts & inhibitors.
Concentration. Changing the concentration of the reactants will affect the rate of reaction. Collision theory states that particles must collide in order for a reaction to take place. The more solute particles that are in solution, the more collisions that are able to occur.
Surface Area. Increasing the surface area of the solute affects the reaction rate because the particles can collide with many others per unit of time.
Temperature. Increasing temperature affects the reaction rate because it increases the average kinetic energy of the particles. When heat is added to a reaction, the particles move faster and collide with more energy.
Catalysts & Inhibitors. Catalysts speed up reactions by lowering the Ea, and inhibitors slow down reactions by raising the Ea. They do not affect the outcome, and thus are not added to the chemical equation.
Concentration. Changing the concentration of the reactants will affect the rate of reaction. Collision theory states that particles must collide in order for a reaction to take place. The more solute particles that are in solution, the more collisions that are able to occur.
Surface Area. Increasing the surface area of the solute affects the reaction rate because the particles can collide with many others per unit of time.
Temperature. Increasing temperature affects the reaction rate because it increases the average kinetic energy of the particles. When heat is added to a reaction, the particles move faster and collide with more energy.
Catalysts & Inhibitors. Catalysts speed up reactions by lowering the Ea, and inhibitors slow down reactions by raising the Ea. They do not affect the outcome, and thus are not added to the chemical equation.