Note 354 — Chapter X · ALUMINIUM; AMPHOTERIC HYDROXIDES; HYDROLYSIS OF SALTS. THE ALUMINIUM AND ZINC GROUPS
Reading edition
When all three of the hydrogen atoms in the hydroxide are ionized, an aluminate ion, AlO33− is formed: Al(OH)3 ⇄ AlO33− + 3 H+. But, as in the case of other weak polybasic acids, a single hydrogen atom is far more readily ionized than are the remaining two (p. 102), and the ion Al(OH)2O−, which is formed by the primary ionization, readily loses water and forms the anhydride ion AlO2−. The most important aluminates are derivatives of this ion.