| http://www.w3.org/ns/prov#value | - (ii) the base is a metal oxide, hydroxide or salt wherein the metal cation is chosen from the group consisting of calcium, magnesium, barium, titanium, zinc, lead, strontium and cobalt and, where a metal salt is used, the pKa value of the conjugate acid of the anion is greater than 2; and
|
