GENERAL SUMMARY AND CONCLUSIONS. 



WE have now recorded the details in connection with seven investigations 

 dealing with the condition of electrolytes in certain non-aqueous solvents, 

 and in mixtures of these solvents with one another. At the conclusion of each 

 investigation a brief summary of the facts and relations established by that 

 investigation has been made. 



It now seems desirable at the close of this monograph to give a general 

 summary of the work done in this field, and the conclusions which can be 

 drawn from it. 



The work of Lindsay included the following solvents : Water, methyl alco- 

 hol, ethyl alcohol, and propyl alcohol, and mixtures of these with one another. 

 The electrolytes which he dissolved in these solvents are potassium iodide, 

 ammonium bromide, strontium iodide, cadmium iodide, lithium nitrate, and 

 ferric chloride. 



A minimum in the molecular conductivity was found for all the salts studied 

 in mixtures of methyl alcohol and water, with the exception of cadmium 

 iodide. A minimum was also found in the mixtures of ethyl alcohol and water 

 especially at 0, the minimum disappearing at 25. Mixtures of methyl 

 alcohol with ethyl alcohol do not show the minimum in conductivity, but in 

 the 50 per cent mixture of these solvents the molecular conductivity of dis- 

 solved electrolytes is less than the mean of the conductivities in the separate 

 solvents. An explanation that was offered to account for the conductivity 

 minimum in the mixed solvents, is that in these associated solvents each 

 solvent diminishes the association of the other. Since dissociating power is 

 a function of the association of the solvent, anything that will diminish the 

 association will diminish its dissociating power. The effect of mixing two 

 dissociating solvents would thus be to diminish the association of both, and, 

 consequently, the dissociating power of each of the solvents. A mixture of 

 two such solvents would, then, dissociate less than either alone, and the con- 

 ductivity of an electrolyte in such a mixture would be less than in the individ- 

 ual solvents the conductivity curve would pass through a minimum. 



This explanation would account for the conductivity minimum in the mixed 

 solvents. The fundamental question, however, is this: Is this explanation 

 correct ? 



We have now considered experimental evidence bearing upon this question. 

 The molecular weights of the alcohol when dissolved in water are, in general, 



normal, i. e., the molecules of the alcohol are the simplest possible. In pure 



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