0 0 Moodle
Home Revision Notes Courses For Schools Blog My Account Cart
Moodle
Edexcel International A Level Chemistry

Topic 9
Kinetics &
Equilibria

Topic 9 asks two questions about every reaction: how fast does it go, and how far? Part 9A Kinetics builds collision theory, activation energy, the measurement of rates, the Maxwell–Boltzmann distribution and catalysts. Part 9B Equilibria covers reversible reactions, dynamic equilibrium, Le Chatelier’s principle and the compromises made in industry. Both are examined in Unit 2 and assessed practically through Core Practical 9.

Exam Unit
Unit 2
WCH12/01 – IAS
Specification Points
9.1 – 9.11
11 points covered
Topic Parts
2 parts
7 revision pages
Exam Board
Edexcel IAL
Pearson International

Revision Notes

9.1 – 9.8
Kinetics
collision theory, rates, catalysts
1
Available

Topic 9A Kinetics

Collision theory and activation energy, measuring and calculating rates, the Maxwell–Boltzmann distribution, and catalysts with their reaction profiles and industrial uses.

Start revising
9.9 – 9.11
Equilibria
dynamic equilibrium, Le Chatelier, industry
2
Available

Topic 9B Equilibria

Reversible reactions and dynamic equilibrium, Le Chatelier’s principle for temperature, pressure and concentration, and the yield-versus-rate compromise in the Haber and Contact processes.

Start revising
Specification Coverage

Topic 9 Kinetics and Equilibria – Edexcel International A Level Chemistry

The following specification points outline the knowledge and skills students are expected to demonstrate for Topic 9.

9A: Kinetics

9.1
understand the effect on the rate of reaction, in terms of collision theory, of changes in:
i
concentration
ii
temperature
iii
pressure
iv
surface area
9.2
understand that reactions take place only when collisions have sufficient energy, known as the activation energy
9.3
be able to calculate the rate of a reaction from:
i
the time taken for a reaction, using rate = 1/time
ii
the gradient of a suitable graph, by drawing a tangent, either for initial rate or at a time, t
9.4
understand qualitatively, in terms of the Maxwell-Boltzmann distribution of molecular energies, how changes in temperature affect the rate of a reaction
9.5
understand the role of catalysts in providing alternative reaction routes of lower activation energy
9.6
be able to draw reaction profiles for uncatalysed and catalysed reactions, including the energy level of the intermediate formed with the catalyst
9.7
understand the use of catalysts in industry to make processes more sustainable by using less energy and through higher atom economy
9.8
be able to interpret the action of a catalyst in terms of a qualitative understanding of the Maxwell-Boltzmann distribution of molecular energies

9B: Equilibria

9.9
know that many reactions are readily reversible and that they can reach a state of dynamic equilibrium in which:
i
the rate of the forward reaction is equal to the rate of the backward reaction
ii
the concentrations of the reactants and products remain constant
9.10
be able to predict and justify the qualitative effect of temperature, pressure and concentration changes on the position of equilibrium in a homogeneous system
9.11
evaluate data to explain why industrial processes compromise between yield and rate of reaction
Specification Coverage

Topic 9 Kinetics and Equilibria – Edexcel International A Level Chemistry

The following specification points outline the knowledge and skills students are expected to demonstrate for Topic 9.

9A: Kinetics

9.1
understand the effect on the rate of reaction, in terms of collision theory, of changes in:
i
concentration
ii
temperature
iii
pressure
iv
surface area
9.2
understand that reactions take place only when collisions have sufficient energy, known as the activation energy
9.3
be able to calculate the rate of a reaction from:
i
the time taken for a reaction, using rate = 1/time
ii
the gradient of a suitable graph, by drawing a tangent, either for initial rate or at a time, t
9.4
understand qualitatively, in terms of the Maxwell-Boltzmann distribution of molecular energies, how changes in temperature affect the rate of a reaction
9.5
understand the role of catalysts in providing alternative reaction routes of lower activation energy
9.6
be able to draw reaction profiles for uncatalysed and catalysed reactions, including the energy level of the intermediate formed with the catalyst
9.7
understand the use of catalysts in industry to make processes more sustainable by using less energy and through higher atom economy
9.8
be able to interpret the action of a catalyst in terms of a qualitative understanding of the Maxwell-Boltzmann distribution of molecular energies

9B: Equilibria

9.9
know that many reactions are readily reversible and that they can reach a state of dynamic equilibrium in which:
i
the rate of the forward reaction is equal to the rate of the backward reaction
ii
the concentrations of the reactants and products remain constant
9.10
be able to predict and justify the qualitative effect of temperature, pressure and concentration changes on the position of equilibrium in a homogeneous system
9.11
evaluate data to explain why industrial processes compromise between yield and rate of reaction