Equilibrium I | Edexcel A-Level Chemistry (9CH0)
Equilibrium I
- 24 questions
- 2 subtopics
- Paper 1: advanced inorganic and physical chemistry
- Paper 1 and Paper 3
Covers what makes an equilibrium dynamic, how Le Chatelier's principle predicts a shift, and the equilibrium constant Kc..
It covers dynamic equilibrium and Le Chatelier's principle and the equilibrium constant Kc.
Sample questions from Equilibrium I
Answer each one closed book first, then open the answer.
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Dynamic equilibrium and Le Chatelier's principle
What type of system is required for a reaction to reach equilibrium?
Show the answer
A closed system, where no reactants or products can enter or leave. -
Dynamic equilibrium and Le Chatelier's principle
In which direction does an increase in total pressure shift a gaseous equilibrium?
Show the answer
Towards the side with fewer moles of gas. -
The equilibrium constant Kc
What concentrations are used in the Kc expression?
Show the answer
The concentrations of the species at equilibrium. -
The equilibrium constant Kc
Why can a solid be omitted from the Kc expression?
Show the answer
Its concentration is effectively constant and is incorporated into the value of Kc.
The 2 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Dynamic equilibrium and Le Chatelier's principle | Recall questions on the conditions for dynamic equilibrium, on predicting a shift from a change in concentration, pressure or temperature, and on industrial compromise conditions. | 16 |
| The equilibrium constant Kc | What Kc describes, writing Kc expressions from equilibrium concentrations, including for N₂(g) + 3H₂(g) ⇌ 2NH₃(g), leaving pure solids and liquids out of heterogeneous equilibria, and working out the units of Kc. | 8 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
Edexcel A-Level Chemistry Active Recall Guide
Every topic, not just this one. 1,534 questions with their answers.