Welcome to this deck on the rate and extent of chemical change. Some reactions, like an explosion, are incredibly fast, while others, like the rusting of iron, are very slow. In this topic, we'll explore what controls the speed, or rate, of a reaction. We'll cover the key factors like temperature and concentration, and explain them using a powerful idea called collision theory. We'll also look at catalysts, reversible reactions, and the concept of dynamic equilibrium. Finally, we'll cover the method for Required Practical 4, which investigates how concentration affects reaction rate.

For a chemical reaction to happen, the reactant particles must collide with each other. But not just any collision will do. This idea is known as collision theory. It states that for a successful reaction, particles must collide with at least a minimum amount of energy. This minimum energy is called the activation energy.

Four main factors can change the rate of a chemical reaction: temperature, concentration of a solution, pressure of a gas, and the surface area of a solid. Let's start with temperature. If you heat up reactants, the reaction usually goes faster. This is because heating gives the particles more kinetic energy, so they move around more quickly. This leads to more frequent collisions, and more importantly, the collisions have more energy, so more of them are successful.