The enthalpy of solution of SRM 1655 (KCl) in H2O

Systematic errors in an isoperibol solution calorimeter measured with standard reference reactions

“…The system for measuring electrical energy was also described [8] and the calculations were similar to those given in [7]. The 1975 with the adiabatic calorimeter [6] and for the e nthalpy of solution value recommended by the P hysical Che rn istry Division of IUPAC [12].…”

“…Results were obtained in this system using various calorimetric procedures in co mmon use at high and low stirring rates. These results are compared with those obtained In a platinum-lined silver, vacuum-jacketed, adiabatic solution calorimeter [6,7,9] for which it has been demonstrated [9] that negligible corrections for heat transfer with the environment are required .…”

“…The sample, SRM 1655 (KCl), is described in detail in the next paper of this issue of the Journal of Research [6]. The portion, C, used here was not sieved but was dried by heating at 800 K for a total of 47 h. The sample, SRM 724a (TRIS), had been stored at 50 percent relative humid· ity.…”

“…Therefore, if the recommended procedures are followed, the sources of error identified here should be minimized; this can be confirmed by measurements of a standard reference reaction [6,7,9,10].…”

“…The standard reference reactions used in this work are (1) the solution of NBS Standard Reference Material (SRM) 1655 2 , KCI, in H 2 0 [6], and (2) the solution of SRM 724a 2a , tris(h ydroxymethyl)aminomethane (TRIS), in 0.1 mol·dm-a Hel soluti~n [7]. The first reacti on is endothermic and the second is exothermic.…”