At equilibrium, the rates of the forward and reverse reactions are equal.
ratef = rater
ratef = K1 [A] [B]
rater = K2 [C] [D]
K1 [A] [B] = K2 [C] [D]
---- = --------
---- = Keg
(2) Simply, the ionization (equilibrium) constant is equal to the product of the
mol/L concentrations of the products formed in the reaction divided by the product of the
concentrations of the reactants.
The equilibrium constant for an acid is called the Ka and for a base the
(4) Ka and Kb are determined for weak acids and bases only. If the Ka or Kb
of a strong acid or base, respectively, were determined it would be an infinitely large
Values of equilibrium constants are interpreted as follows:
(a) The constant indicates the strength of a weak electrolyte.
(b) The smaller the value of the Ka or Kb, the weaker the acid or base
What is the [H ] of a 0.100 mol/L solution of acetic acid if the Ka for HC2H3O2 is
1.75 X 10-5?
Solution. Determine the equation for the dissociation of the weak acid.
HC2H3O2 <====> H+ + C2H3O2-