The dissolution of propan-1-ol and dilution of 10 wt.% propan-1-ol solution in water as calibration and test reactions in solution calorimetry

The enthalpy of solution of propan-1-ol in water is a convenient and reliab le calibration and test reaction in titration microcalorimetry. The solutio n enthalpy varies significantly with concentration; hence: it is usually ne cessary to make extrapolations to infinitely dilute solution to determine D elta(sol)H(m)(infinity) in order to derive a value suitable for comparison. We outline the thermodynamic formalism for the titration solution experime nts and indicate an extrapolation procedure. An experimental example is giv en. Since less energetic test reactions are often desirable, the dilution o f 10 wt.% propan-1-ol solution in water has been suggested as such a reacti on. Thus, we have made dilution measurements in order to explore the accura cy of the reported enthalpy value and found that the uncertainty is, at pre sent, at least a couple of percent. Some experimental considerations when p erforming titration microcalorimetric experiments are discussed. (C) 2000 E lsevier Science B.V. All rights reserved.