Optical constants for sulfuric and nitric acids

within 5% of our values. An average heat of solution of 2320 cal/g-mol is determined from the slope of the correlation equation. That the correlation coefficient is 50 close to unity demonstrates that no appreciable deviation from a constant heat of solution exists over the 12-20M range of nitric acid concentrations. The log of the solubility of HI308 varied linearly with the nitric acid molarity, showing no apparent perturbation at the azeotrope of " 0 3 and water. Molecular iodine was not present in the solutions except at 100°C where trace quantities (up to 33 ppm) were detected.