Density, Viscosity, and Thermal Conductivity of Electronic Grade Phosphoric Acid

Abstract

The densities and viscosities of electronic grade phosphoric acid (EGPA) aqueous solutions with the mass fraction of H3PO4 in the range of (78.7 to 90.2) % and temperatures from (283.15 to 313.15) K were measured. The densities range from (1.606 to 1.758) g·cm−3 with the mass fraction in the range of (78.7 to 90.2) % under experimental temperature. The viscosities range from (14.63 to 134.56) mPa·s with the mass fraction in the range of (78.7 to 90.2) % under experimental temperature. It is found that the measured densities and viscosities are well-correlated with the temperature and mass fraction of H3PO4 and are fitted to the regression equations. The thermal conductivities of EGPA coarse crystal (mixture of H3PO4·0.5H2O crystal and phosphoric acid aqueous solution) with the initial mass fraction of H3PO4 in the range of (84.2 to 90) % and temperatures from (280.15 to 298.15) K were measured by the cooling rate of 2 K·h−1 with a total cooling of (3 to 4) K under the initial temperature, which simulated ...