Chemical Equilibrium

Delving into the world of changes in chemistry

Select what you want to calculate.

Equilibrium & Le Chatelier

Relationship: ΔG° = −RT ln K (standard conditions).

Calculate the equilibrium constant from standard Gibbs free energy change.

ΔG° (kJ·mol⁻¹)

Typical equilibrium ΔG° values are tens of kJ·mol⁻¹, not 10⁻⁴.

Temperature T (K)

Calculate standard Gibbs free energy change from the equilibrium constant.

Equilibrium constant K Temperature T (K)

Calculate equilibrium constants and predict reaction direction by comparing Q and K.

aA + bB ⇌ cC + dD

a (A)

b (B)

c (C)

d (D)

[A] or Pₐ

[B] or Pᵦ

[C] or P𝒸

[D] or P𝒹

Use concentrations for Kc / Qc or partial pressures for Kp / Qp.

These are equilibrium values (calculate K from them)

Determine equilibrium concentrations using ICE tables (linear approximation: neglect x in terms with large initial concentrations).

aA + bB ⇌ cC + dD

a (A)

b (B)

c (C)

d (D)

[A]₀

[B]₀

[C]₀

[D]₀

Assume products start at 0 ([C]₀ = 0 and [D]₀ = 0, if present) Solve exactly (quadratic equation)

Qualitative → logical → semi-quantitative prediction of equilibrium shifts.

Stress type