Apparent and partial molar heat capacities and volumes of aqueous HClO4 and HNO3 from 10 to 55 °C

Abstract

Apparent molar heat capacities and volumes of aqueous solutions containing HClO4 and HNO3 have been determined from 10 to 55 °C. The temperature dependences of the standard state heat capacities and volumes of ClO4− (aq) and NO3− (aq) from 10 to 55 °C were found to be well represented by the following equations:[Formula: see text]Combination of the experimental results with semiempirical equations for ion–solvent interaction has led to predictions of the standard state volumes and heat capacities for these ionic species at higher temperatures. Keywords: heat capacities, volumes, nitric acid, perchloric acid.