Relative humidity-temperature relationships of some saturated salt solutions in the temperature range 0 degree to 50 degrees C

Abstract

The relative humidity-temperature relationships have been determined in air in equilibrium with saturated salt solutions of lithium chloride. LiCl. H2O; magnesium chloride, MgCl2. 6H2 O; sodium dichromate, Na2Cr2O7.2H2O; magnesium nitrate, Mg(NO3)2. 6H2O; sodium chloride, NaCl; ammonium sulfate, (NH4)2SO4; potassium nitrate, KNO3; and potassium sulfate, K2SO4, over a temperature range of 0 to 50C, using the dewpoint method. The relative humidity is a continuous function of temperature, and, except for sodium chloride, is monotonic. The curve for sodium chloride increases from 74. 9 percent relative humidity at 0C to a maximum of 75.6 percent at 30C and then gradually decreases to 74.7 percent. The maximum change in relative humidity with temperature, about 15 percent relative humidity as the temperature increases from 0 to 50C, occurs with saturated salt solutions of sodium dichromate and magnesium nitrate.