CHEMICAL THEORY OF SOLUTIONS. PART T. 21 



mixture that the composition can be determined from the boiling 

 point. For solutions with more than two comj)onents the equation 

 becomes indeterminate. 



Young and Fortey (Journ. Chem. Soc, 83, 45; 1905) 

 tested the applicability of the equation (9) to various binary- 

 solutions approximating more or less closely to the ideal solution. 

 Of these the mixture of chloro- and bromobenzene satisfied con- 

 ditions (1) and (2) most closely, and they found that the 

 boiling point of the mixture could be represented quite well by 

 equation (9). For <p{T) they employed Biot's formula. The 

 calculation with equation (11) is of course much simpler, while 

 the agreement is nearly as good, as is shoAvii in the following 

 table : 



The difierences between the observed and calculated molar fractious 

 do not exceed 3^4, which corresponds to about .05° in the 

 measurement of temperature, and seems to be nearly equal to 

 the limit of error. The value of b employed in the calculation 

 is 10.9, and is nearly equal to the mean value. 

 If only one component be volatile, then 



s^j = p^ = c\ P, 



or C\<f,{T) = %^ 



In the cases where the simple equation {A) is sufficed 



a,— 



7i 





