Equilibrium · expressions and response
Understand Kc
Practise Kc expressions, then use the Haber model to test changes in concentration, pressure, temperature and catalyst.
Dynamic equilibrium model
N₂(g) + 3H₂(g) ⇌ 2NH₃(g)
Exothermic forward reaction, ΔH ≈ −92 kJ mol⁻¹. This teaching model uses illustrative Kc values while keeping every shift and equilibrium calculation consistent.
Equilibrium concentrations
Forward→←Reverse
System data
- Volume
- 10.0 dm³
- Temperature
- 400 K
- Kc at this temperature
- 0.500
- Current Qc
- 0.500
Kc and Qc
Kc is fixed for a given reaction at a given temperature. Qc uses the concentrations at the current moment. After a disturbance, the system shifts until Qc equals Kc again. Only a temperature change alters Kc.