Activity coefficients and spectroscopic properties of associated solutions

Activity Coefficients and Spectroscopic Properties of Associated Solutions. 

The results established in the preceding paragraph may be verified by comparing the thermodynamic properties and the spectroscopic properties of associated solutions. Let us consider, for example, a solution of ethanol in carbon tetrachloride. The valency vibration of the OH group gives rise to two distinct infra-red absorption bands depending upon whether the OH group is in a monomer or in an associated complex. The fraction of molecules of alcohol which remain in the monomeric state can therefore be determined from measurements 

The logarithms of yY and y s can be expressed as series in the mole fractions as in (21.50) and for the present purpose we retain terms up to the third power in mole fractions. We have then 

Choosing now a very dilute solution of A in B as standard reference state, and employing (26.26), we obtain 

Domain of Validity of the Ideal Associated Solution Model. 

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