The degree to which a weak base dissociates is given by the base-ionization constant, kb. for the generic weak base, b b(aq)+h2o(l)⇌bh+(aq)+oh−(aq) this constant is given by kb=[bh+][oh−][b] strong bases will have a higher kb value. similarly, strong bases will have a higher percent ionization value. percent ionization=[oh−] equilibrium[b] initial×100% strong bases, for which kb is very large, ionize completely (100%). for weak bases, the percent ionization changes with concentration. the more dilute the solution, the greater the percent ionization. ammonia, nh3, is a weak base with a kb value of 1.8×10−5.parta what is the ph of a 0.245 m ammonia solution? partb what is the percent ionization of ammonia at this concentration?