The Vapor Pressure of HCl - Water and Salt - HCl - Water Solutions Below OC.

Liquid solution analyses were completed. The complete vapor-liquid equilibria data are tabulated for hydrochloric acid solutions ranging in molality from 5.0 to 15.7, saturated with CaCl2 at nominal temperatures ranging from 0 to -40C. The CaCl2-HCl-water system exhibits a maximum pressure azeotrope under these conditions. Pure hydrochloric acid and NaCl-HCl-water systems exhibit minimum pressure azetropes in the same temperature range. At acid molalities greater than about 9, the vapor phase contains about 94 HCl and for all molalities there is an increase in the partial pressures of HCl and water over what is observed with pure hydrochloric acid. Because of these characteristics, it is predicted that the presence of CaCl2 in reduced smoke rocket plumes will not contribute as strongly to secondary smoke as will NaCl. Originator supplied keywords include Plumes, Salt solutions, Partial pressures, Hydrochloric acid, Sodium chloride.