Chapter 18.1

Rates of Reaction

Learning Objectives

• Understand what a reaction rates are a measure of

• Know the main tenets (points) of collision theory

• Be able to identify the factors that affect reaction rates

• Be able to interpret reaction diagrams

Chemical Kinetics

Chemical kinetics is the study of reactions rates

A reaction rate is the change in concentration of a reactant/product per unit time (Concentration is molarity)

Collision TheoryThree conditions must be met …

1- Atoms/ions/molecules must collide

2- They must collide with enough energy

3- Must hit each other in a proper orientation

Collision Theory

Collision Theory

collision theory orientation

collision theory video game analogy

Factors Affecting Reaction Rates

Reaction rates are affected by:–Temperature

–Concentration

–Particle Size

–Catalysts/Inhibitors

Factors Affecting Reaction Rates

Lets summarize:– Temperature

(higher temperature makes rate faster)

– Concentration

(higher molarity makes rate faster)

– Particle Size

(smaller particles makes rate faster)

– Catalysts/Inhibitors

Energy Diagram-Endothermic

Energy Diagram-Exothermic

Effect of Catalyst