Vibrational spectral studies of solutions at elevated temperatures and pressures. VI. Raman studies of perchloric acid

Abstract

Raman spectra of perchloric acid in water have been measured for solutions spanning a wide concentration range and, for two specific concentrations, a wide range of temperatures. The acid is completely dissociated down to a water:acid mole ratio of about 1.8 at room temperature. At elevated temperatures it is still a very "strong" acid. As the concentration increases the apparent symmetry of the ClO4− ion decreases and a small amount of a new species assigned as associated ClO4−•(Haq)+ can be detected. The effects on the OH stretching bands of water, of temperature, ClO4−, and the excess acid protons are discussed.