01Systems push back
If a stress disturbs equilibrium, the system shifts to relieve it. Add reactant → shift right. Remove product → shift right. Increase pressure (smaller volume) → shift toward fewer gas moles.
Temperature: treat heat as a reactant (endothermic) or product (exothermic). Only temperature changes K.
02Notebook box
Inert gas at constant volume → no shift. Catalyst → no shift.
Worked example: N₂ + 3H₂ ⇌ 2NH₃ + heat. Cooling → shift right, K increases.