Keq Expression

• Derived from the balanced equations for the reaction

• Denoted keq. This value is called the equilibrium constant

• General Formulas:

  • Reaction equation: wA + xB =(equilbrium arrows) yC + zD

    • uppercase → reactants/products

    • lowercase → balanced equation coefficients

  • Equilibrium expression:

    • Keq = products/reactants

• Keq has no units

• Temperature values must be included because Keq values change with temperature. However, the other stresses have no effect on the equilibrium constant.

• *if the equilibrium system involves solids or liquids, they are not included in the equilibrium expression since they have a constant concentration.

• Only gas an aqueous are included in the equilibrium expression.

High Keq - Favors products (more products)

• Usually very high but keq>1

Small Keq - Favors reactants

• Usually very low but keq<1

Keq is close to 1 (or equal) = Same amount of reactants + products

Keq wll never be zero or negative.