ENTHALPY OF SOLUTION OF SRM 1655 (KCl) IN H2O.

Abstract

The value for the enthalpy of solution of SRM 1655 (KCl), DELTA H** degree (500 H//2O, 298. 15 K) equals (235. 86 plus or minus 0. 23)J multiplied by (times) g** minus **1 or (17. 584 plus or minus 0. 017)kJ multiplied by (times) mol** minus **1, was obtained from measurements in an adiabatic calorimeter, and confirmed by measurements in an isoperibol calorimeter. Enthalpy of solution measurements are reported in the temperature range 296 to 358 K, at molalities between 0. 005 and 0. 18 mol multiplied by (times) kg** minus **1, for various ranges of particle size up to 1000 mu m, and in CO//2- saturated solutions. Observations were also made relative to the hygroscopicity, removal of occluded H//2O, and homogeneity of SRM 1655. Between 296 K and 303 K, DELTA C//p equals minus (2. 076 plus or minus 0. 087) J multiplied by (times) g** minus multiplied by (times) K// minus **1 or minus (154. 8 plus or minus 6. 4) J multiplied by (times) mol** minus **1 multiplied by (times) K** minus **1 for the reaction of SRM 1655 in 500 H//2O.