Studies in condensed phosphates. Part I. Sodium metaphosphates and their derivatives with calcium, barium, and zinc salts

Derivatives with the formulas [Na 4 Ca(PO 3 ) 6 ] n , [Na 4 Ba(PO 3 ) 6 ] n , and [Na 4 Zn(PO 3 ) 6 ] n have been prepared by heating together mixtures of NaH 2 PO 4 .2H 2 O, CaO (or Ba(OH) 2 .‐8H 2 O or ZnO), and (NH 4 ) 2 HPO 4 in the molar ratios of 4:1:2 at 700 and 800°C. for 1 hr. The number‐average molecular weights of these derivatives have been measured by the endgroup titration method. Their conductance has been measured in aqueous solution of varying concentration, and their properties compared with those of Graham's salt (NaPO 3 ) n prepared under similar conditions.