The preparation of the salts of heteropolyacids by tempering a mixture of the solid components

The method of prolonged tempering of a mixture of the solid components Na4As2O7 + ZO3 + Na2ZO4 (Z = Mo, W) was successfully used to prepare new compounds in the pure state and thermoanalytical analysis yielded the empirical formula, Na24As2Z22O83. The two compounds melt congruently and have a melting point of 597 °C (Z = Mo) and 691 °C (Z = W). To make the determination of the empirical formula more objective, a computation method was developed for treatment of the thermoanalytical data and two computer programs were written.