Activity cryoscopic determination

Cryoscopic Determination of Mean Ionic Activity Coefficient. 

A multicyclic soluble polymer was obtained from the zinc chloride-catalyzed condensation of ferrocene and acetone (IV-18) (27, 28). The polymer was a brown powder softening at 320°-360°C, and was soluble in benzene. Its molecular weight was determined cryoscopically and was about 3000. No crystallinity was detected by X-ray analysis. The material exhibits a signal in its ESR spectrum and has semiconducting properties. Its specific electroconductivity (50°C) was 1.23 x 10 i2 ohm- cm i with an activation energy of 0.67 eV. 

The use of cryoscopic measurements for the determination of activity coefficients in aprotic solvents has been very limited, although much information is available on the evaluation of molecular weights and studies of solvent association. Relative to protic solvents more information is available and the investigations of Gillespie and coworkers in sulphuric acid and related compounds have been compiled to indicate the general scope of this technique in protic solvents. The information is presented in alphabetical order by solvent. 

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