Physical and chemical changes and rate of reaction

Learning objectives

Identify physical and chemical changes and describe the differences between them

Describe the effect of concentration, pressure, surface area, temperature and the presence of a catalyst on the rate of a reaction, state that a catalyst increases the rate without being changed at the end, and state that enzymes are proteins that act as biological catalysts

Describe practical methods for investigating rate, such as measuring the volume of gas collected in a gas syringe or the loss in mass on a balance against time, and interpret the data and graphs obtained

Describe collision theory in terms of the number of particles per unit volume, the frequency of collisions, the kinetic energy of the particles and the activation energy (Extended)

Use collision theory to explain the effects of concentration, pressure, surface area and temperature on rate, and explain that a catalyst increases the rate by providing an alternative pathway with a lower activation energy (Extended)