226^ Linebarger — Tension of Mixtures of Normal Liquids, 



Aet. XXIX. — On the Surface Tension of Mixtures of Nor- 

 mal Liquids / by C. E. Linebaeger. 



In the ingenious method of estimating between certain 

 limits of temperature the molecular mass of a liquid devised 

 by Ramsay and Shields,"^ it is assumed that the various kinds of 

 molecules that may occur in a liquid are uniformly distributed 

 throughout the entire body of the liquid so that no one kind 

 predominates in its surface. That such an assumption is in 

 accordance vs^ith the facts of the case has been proven by 

 Ramsay and Aston, f who determined the superficial tensions 

 and energies of several mixtures of liquids that do not undergo 

 appreciable polymerization. While in some instances they 

 found that the molecular surface energies of mixtures were 

 the mean of the molecular surface energies of their component 

 liquids, yet in others such was not the case. 



The object of this paper is to add to our knowledge of the 

 relations of the capillary constants of normal liquids and their 

 mixtures. The determinations of this physical property were 

 made with the apparatus described in a previous article in this 

 Journal, p. 110. The liquids employed were of a high grade 

 of purity and the composition of their mixtures was deter- 

 mined with the greatest care. 



The following tables give the data obtained, the headings to 

 each of which render any explanation here needless, except, 

 perhaps, for the last column, where the minus sign before a 

 number indicates that the observed surface tension is greater 

 than the calculated, and the plus sign the opposite. The sur- 

 face tensions are given in dynes per centimeter. 









Table 



I. 





Surface Tension of 



Mixtures 



of Benzene and Toluene. 



Percentage 

 Composiiion. 



Molecular 



Percentage 



Composition. 



Temperature 25. °0 

 Observed Calculated 

 Specific Surface Surface 

 Gravity. Tension. Tension. 



Differ- 

 ences. 



CeHe 



C7H8 



CeHe 



CHs 







0.000 



100.000 



0.000 



100.000 



0.85680 26.74 





30.588 



69.412 



34.230 



65.770 



0.86635 27.00 26.91 



— 0.09 



66.576 



3dA24: 



70.240 



29.760 



0.87143 27.19 27.13 



- 0.06 



90.720 



9.280 



92.011 



7.989 



0.87366 27.28 27.24 



-0.04 



91.556 



8.444 



92.750 



7.250 



0.87528 27.27 27.24 



-o.oa 



100.000 0.000 100.000 0.000 0.8'/661 27.29 



*Zeitsohr. f. phys. Chem., xii, p. 433, 1893. 

 f Ibid., XV, p. 89, 1894. 



