Properties of a Mixture of Liquids. 

 Benzene and Ethyl Acetate. 



411 



Per cent. 













Per cent. 



benzene in 

 liquid. 



Do. in 



distillate. 



Temp, of 

 distillation. 



*7- 



t. 



t (calc). 



in distillate 

 (calc). 



12-9 



1305 



503 



•1481 



•1501 



•1514 



13-15 



25-85 



25-7 



50-5 



•3486 



•3459 



•3449 



25-65 



50-9 



49-7 



49-3 



1037 



•9881 



•9845 



49-6 



510 



49'8 



50-2 



1-041 



•9920 



•9881 



49-7 



75-6 



73-9 



48-7 



3-098 



2-831 



2-822 



73-8 



87-45 



85-85 



520 



6-968 



6-067 



6-153 



86-0 



It should be noted that the first of the above mixtures gives 

 a distillate containing more benzene than itself ; thus 

 showing that its saturation-pressure must be greater than 

 that of pure ethyl acetate ; and that there must be some 

 mixture (containing more than 12*9 per cent, of benzene) 

 having a maximum vapour-pressure, and distilling without 

 change of composition. 



A diagram was drawn showing the relation between log q 

 and log t. This was found to be practically linear, in accord- 

 ance with the assumption made in the earlier sections that 

 l = kq r , and could best be represented with the constants 

 log k = 1*978, ?* = 0*962. From this are derived the numbers 

 in columns 6 and 7 above ; the agreement with the observed 

 percentages is within the limit of errors of observation. 



Benzene and Methyl Acetate. 



Per cent, 

 of benzene 

 in liquid. 



Do. in 

 distillate. 



Temp, of 

 distillation. 



1- 



t. 



t (calc). 



Per cent. 



in distillate- 



(calc). 



18-5 



310 



47-95 



67-0 



86-0 



11:8 



19-4 

 32-1 

 49-1 

 73-45 



50°0 

 48-5 

 50-0 

 49-6 

 51-0 



•2276 

 •4495 

 •9208 

 2032 

 6153 



•1335 

 •2407 

 •4730 

 •9638 

 2769 



•1299 

 •2429 

 •4700 

 •9734 

 2-698 



11-5 

 1955 



32 

 49-3 

 72-95 



The numbers in the last two columns are calculated from 

 the equation 



log < =1-705 -f 0-92 log q. 



The temperature of distillation was not as constant as is 

 desirable ; but in view of the results of Brown's experiments 

 discussed in the preceding section, it is not likely that any 

 considerable error has arisen on that account. 



