Safety boundary
Use simulations and supplied concentration data only; no unsupervised reactive mixtures.
Explicit chemistry instruction
At dynamic equilibrium, forward and reverse reaction rates are equal.
Equal rates do not mean reactant and product concentrations are equal; they become constant at values set by the system and temperature.
Equilibrium requires a reversible process in a closed-enough system for both directions to matter.
Vocabulary: dynamic equilibrium; forward rate; reverse rate; concentration; reversible reaction.
Worked example
If forward and reverse rates both become 0.20 mol/L·s, concentrations can remain constant even though molecules continue reacting.
Guided question
Why can concentration stay constant while particles continue to react?
Independent work
- Interpret a rate-versus-time graph.
- Distinguish equal rate from equal concentration.
- State one system assumption.
Misconception check
Equilibrium is not a stopped reaction.
Formative check
What equality defines dynamic equilibrium?
Reveal response
Forward rate equals reverse rate.
Mentor evidence conference
Ask Archaemenes to audit equilibrium assumptions, graph interpretation, and whether the evidence supports the conclusion.
Teacher guidance
Foundation: Use rate/concentration graphs.
Core: Explain dynamic equilibrium.
Extended: Connect microscopic events to macroscopic constancy.