SCH4U - Chemistry 12 (2024-25) - A

Summary

• The equilibrium constant (Keq) describes a system at equilibrium based on the concentration of products and reactants at equilibrium
• K_eq = ([C]^c[D]^d) / ([A]^a[B]^b)
• Solids and pure liquids are not included in the equilibrium constant equation as their concentrations are constant
• A large K_eq means that the products are favoured (products have a higher concentration than the reactants) at equilibrium while a small K_eq means the reactants are favoured at equilibrium
• To calculate Keq from initial concentrations, an ICE table can be used
• Certain common reactions have specific equilibrium constants associated with them
• K_p is the equilibrium constant used for reactions involving only gases at constant pressure
• When calculating K_p, we use the partial pressures of each gas to instead of concentrations when plugging values into the equilibrium constant expression
• K_sp = solubility product constant, used for the equilibrium of a saturated ionic solution where an equilibrium forms between the solid and dissolved ions
• K_a = acid dissociation constant, used for the equilibrium that forms when a weak acid dissolves in water
• K_b = base dissociation constant, used for the equilibrium that forms when a weak base dissolves in water