Critical Evaluation of the Thermodynamic Properties of Na2Cr2O7, K2Cr2O7, Na2Mo2O7, K2Mo2O7, Na2W2O7, and K2W2O7

Abstract

This study outlines an extensive investigation of crystallographic data and thermodynamic properties (including solid-solid transition and fusion) for sodium dichromate, potassium dichromate, sodium dimolybdate, potassium dimolybdate, sodium ditungstate, and potassium ditungstate. A thorough literature review was conducted to obtain a good understanding of the data available in the literature, and a critical and complete evaluation has been performed from room temperature to above the melting temperatures. This work is one of the key steps towards the development of a thermodynamic model for the Na+, K+//Cl−, SO42−, CO32−, CrO42−, Cr2O72−, MoO42−, Mo2O72−, WO42−, W2O72−, O2− system, relevant for high temperature corrosion in atmospheres containing O-H-S-C-Cl and alkali salts.