Safety boundary
Use virtual equilibrium perturbations and supplied datasets only; no unsupervised color-change chemistry.
Explicit chemistry instruction
Compression changes gas concentrations or partial pressures and can shift equilibria with unequal gas-mole counts.
In the simple model, compression tends to favor the side with fewer gas particles.
If gas-mole counts are equal, pressure change may produce little composition shift.
Vocabulary: pressure; volume; gas moles; partial pressure; equilibrium.
Worked example
For A(g)+B(g)⇌C(g), compression tends toward the one-mole product side.
Guided question
Why may compression have little effect on A(g)⇌B(g)?
Independent work
- Count gas moles for four equations.
- Predict pressure shifts.
- Identify one no-net-gas-mole case.
Misconception check
Pressure rules apply to gaseous species, not blindly to every stoichiometric coefficient.
Formative check
Which side is generally favored by compression when the rule applies?
Reveal response
The side with fewer gas moles.
Mentor evidence conference
Ask Archaemenes to audit whether Q, K, and rate effects are being kept distinct.
Teacher guidance
Foundation: Use gas-count tables.
Core: Predict shifts.
Extended: Connect pressure change with Q.