Degree of dissociation. Strong and weak electrolytes

10 DEGREE OF DISSOCIATION. STRONG AND WEAK ELECTROLYTES When discussing the theory of electrolytic dissociation, it was stated that it is a reversible process and its extent varies with concentration (and also with other physical properties, like temperature). The degree of dissociation (a) is equal to the fraction of the molecules which actually dissociate. 

The value of a may vary within 0 and 1. If a = 0, no dissociation takes place, while if a = 1 dissociation is complete. 

The degree of dissociation can be determined by various experimental methods. 

The cryoscopic and ebullioscopic techniques are based on the measurement of the depression of the freezing point and the elevation of the boiling point respectively. As mentioned before, the experimental values of these were found to be higher than the theoretical ones. The ratio of these 

by calculating i from experimental data, a can be computed easily. 

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