Safety boundary
Use simulations and supplied concentration data only; no unsupervised reactive mixtures.
Explicit chemistry instruction
A reaction quotient Q has the same algebraic form as K but uses current, not necessarily equilibrium, values.
If Q
This predicts direction of change, not speed.
Vocabulary: reaction quotient; Q; direction; composition; equilibrium.
Worked example
If K=10 and current Q=2, the system is product-poor relative to equilibrium and tends forward.
Guided question
What direction is predicted if Q is larger than K?
Independent work
- Compare Q and K for four cases.
- Predict direction.
- State why no rate is implied.
Misconception check
Q versus K predicts direction, not how quickly equilibrium is reached.
Formative check
What does Q=K indicate?
Reveal response
The composition is at equilibrium under the model.
Mentor evidence conference
Ask Archaemenes to audit equilibrium assumptions, graph interpretation, and whether the evidence supports the conclusion.
Teacher guidance
Foundation: Use inequality cases.
Core: Predict direction.
Extended: Connect Q/K logic to free-energy ideas.