This subtopic builds on concepts from Stage 1 subtopic 4.4.
The rates of a reaction at different times can be compared by considering the slope of a graph of quantity or concentration of reactant or product against time.
- Draw and interpret graphs representing changes in quantities or concentration of reactants or products against time.
Animated notes: Graphs of rate
Videos: Graphing rate | Rates of reaction part 1
Rates of reaction can be influenced by a number of factors, including the presence of inorganic and biological catalysts (enzymes).
- Predict and explain, using collision theory, the effect on rates of reaction due to changes in:
- concentration
- temperature
- pressure (for reactions involving gases)
- surface area
- the presence of a catalyst.
Animated notes: Rate factors
Videos: Effects 1 | Effects 2 | Rates of reaction part 2
Simulation: Reactions & rates
Energy profile diagrams can be used to represent the relative enthalpies of reactants and products, the activation energy, and the enthalpy change for a chemical reaction.
- Draw and interpret energy profile diagrams.
Animated notes: Energy profile
Animation: Collision theory
Simulation: Energy Profile Analogy
