THE NEWTON INTERPOLATION FORMULAE FOR DETERMINATION OF THE STANDARD ENTHALPIES OF FORMATION OF RARE-EARTH TELLURITES

Rare-earth tellurites are comparatively new group inorganic compounds, which recently take the interest of many of the scientists. The perspectives of these compounds are in their application in contemporary technologies such as the nanotechnologies, silicate industry, as a dielectric and ferroelectric material; in medicine as additions to different kinds of drugs for curing of hard healing diseases; and also as agricultural microfertilisers. The thermodynamic properties such as standard enthalpy (Delta H-298(0)), standard entropy (Delta S-298(0)) and the Gibbs free energy (Delta G(298)(0)) of rare-earth tellurites are particularly necessary not only for the development of rational technologies for their preparation, but also for the exploitation in lasers and semiconductive apparatus, in which they are applied. The purpose of the present work is the determination of the standard enthalpies of the synthesised rare-earth tellurites on the basis of several proposed methods. Assessment of the precision is performed. The relative percentage deviation is small, which is a guarantee for the precision of the provided calculations. The function between the standard enthalpies (Delta H-298(0)) of formation and the molecular masses of the rare-earth tellurites is presented in graphics and studied as well. The synthesised rare-earth tellurites and their thermodynamic properties are necessary for the database gathering of information for an important part of the inorganic chemistry, that of the chemistry of tellurium.