Topic 9B
Equilibria
Equilibria are reversible reactions that settle into a state of balance. These pages define dynamic equilibrium, use Le Chatelier’s principle to predict how the position of equilibrium responds to changes, and apply both to the compromises made in the Haber and Contact processes.
Revision Notes
3 revision notes, in the order the specification teaches them.
Dynamic Equilibrium
Dynamic equilibrium: reversible reactions, equal forward and reverse rates, constant concentrations, closed systems and the position of equilibrium.
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Le Chatelier’s Principle
Le Chatelier’s principle: temperature, pressure and concentration changes, catalysts, and the ammonia and chromate equilibria as examples.
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Equilibria in Industry
Equilibria in industry: the Haber and Contact processes, compromise temperature and pressure, catalysts and evaluating yield data.
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Equilibria Map
Edexcel International A Level Chemistry · Unit 2 · Topic 9B Equilibria
The whole section on one A4 page: dynamic equilibrium, reversible reactions, concentration, pressure, temperature and catalysts, and industrial conditions, with worked examples.
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Specification
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Self-assessment · 9 points
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9.9
- i
know that many reactions are readily reversible and that they can reach a state of dynamic equilibrium in which: the rate of the forward reaction is equal to the rate of the backward reaction
Revise - ii
know that many reactions are readily reversible and that they can reach a state of dynamic equilibrium in which: the concentrations of the reactants and the products remain constant
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9.10
- a
be able to predict the qualitative effect of temperature changes on the position of equilibrium in a homogeneous system
Revise - b
be able to justify the qualitative effect of temperature changes on the position of equilibrium in a homogeneous system
Revise - c
be able to predict the qualitative effect of pressure changes on the position of equilibrium in a homogeneous system
Revise - d
be able to justify the qualitative effect of pressure changes on the position of equilibrium in a homogeneous system
Revise - e
be able to predict the qualitative effect of concentration changes on the position of equilibrium in a homogeneous system
Revise - f
be able to justify the qualitative effect of concentration changes on the position of equilibrium in a homogeneous system
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9.11
- 9.11
evaluate data to explain why industrial processes compromise between yield and rate of reaction
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