Reflectance and complex refractive indices in the infrared for aqueous solutions of nitric acid

Near‐normal incidence reflectance spectra relative to water were measured throughout the 310 to 5000 cm−1 spectral region for 0.5, 1, 2, 4, 8, and 15.7 M aqueous solutions of nitric acid. Spectral values of the complex refractive index N (ν) =n (ν)+ik (ν) of the nitric‐acid solutions were computed by use of Kramers–Kronig techniques. Values of N (ν) are presented in graphical and tabular form. The spectra were further analyzed to determine the central frequencies, half‐widths, and strengths of infrared bands due to intra‐ and intermolecular vibrational modes of liquid water and intramolecular vibrational modes of NO3−, H3O+, and HNO3.