Subject: Hildebrand solubility constant

From: [email-masked] (Hr Dr. S. Shapiro)
Date: Fri, 27 May 1994 11:00:23 +0100 (MEST)

I am interested in computing Hildebrand solubility parameters for some or-
ganic molecules, according to the approximation

          d = [{deltaH(v)-RT}/V(l)]**0.5

where

     d = Hilde. sol. par.

     deltaH(v) at 298oC (cal/mol) = -2950 + 23.7 Tb + 0.02(Tb)**2

     Tb = boiling point of the compound of interest

     V(l) = molal volume (volume of 1 kg of substance?)

(see Hildebrand & Scott, The Solubility of Nonelectrolytes, Reinhold Publ.
Corp., 1950, pp. 424-427).  According to this reference (p. 439), the value of
d for nitrobenzene = 10.0; according to the Aldrich Catalogue (1992-3), for
nitrobenzene Tb = 210.5oC = 483.5oK and density = 1.196 g/mL.

     For deltaH(v) I calculate

          -2950 + 23.7(483.5) + (0.02)(483.5)**2 = 13184 cal/mol

     From the above density, I calculate v(l) = 0.836 L/kg.

What is the value of R that I must use in order to obtain d from the above
values?

     Please don't clog the bandwidth; send your replies directly to me at

                   Internet: [email-masked]

     Thanks to all responders in advance.

                                                           Sincerely,

                                                           S. Shapiro