440 Mrs. K. Stratton and Prof. J. R, Partington on 



1st Experiment. — Wt. -of Benzophenone = 35*660 grms. 

 = W. ; Time of passage of current = 17 mins. 30 secs. = £ ; 

 Current strength = 0*85 amp. = 0; Resistance o£ coil = 4*25 

 ohms = R. .*. L = C 2 R//4*18W = 21*64 gram cal. 



2nd Experiment. — C = l*48 amps. ; "Wt, of Benzophenone 

 = 31*135 grms. ; R = (a new coil used here) 1*33 ohms; 

 £=15 mins. .*. L = 2179 gram cal. 



3rd Experiment. — C= 1*08 amps. ; R = 1*33 ohms ; 

 £ = 28 mins. 58 sees. ; Wt. of Benzophenone = 29*757 grms. 

 .*. L = 21*58 gram cal. 



From these results we may calculate the value of the 

 Molecular Depression of the Freezing Point from formula 

 E = *02T 2 /LW. 



For L= 21-64, E = 95*ll 



For L = 21-79, E-9461 



For L = 21-68, E = 95*04 



MeanL = 21*70, Mean E = 94-92 



The values quoted by N ernst (Theoretische Chemie, 7 Aufl. 

 p. 149, 1913) are L = 21;5 (observed) and E = 95 (obs.) ; 

 E = 96 (calculated from L). 



The authority given by ISTernst for these values is 

 Eykmann. The observed values of E given in Eykmann's 

 paper, however, range between 68 and 100. It might 

 also be noted here that the values given by Eykmann 

 for phenol are arranged under two headings : those for 

 phenol with a M.P. 36° 0., and those for a phenol of 

 M.P. 39~ C. These results are unreliable for obvious 

 reasons. 



In the monograph Cryoscopie, by Raoult, 1901, page 70, 

 a table is given of values derived from the constant E. This 

 is divided by the molecular weight of the solvent, giving a 

 constant which represents the lowering of the freezing-point 

 produced by dissolving 1 gram molecule of the solute in 

 100 grms. of the solvent expressed in gram molecules, which 

 constant it is stated should be in the neighbourhood of 0'62. 



The value Raoult gives for this constant for Benzophenone 

 is 0*54 ; the value for the mean of our experimental results 

 is 0*522. The value for E, therefore, used by Raoult from 

 the work of Eykmann, to which he refers, is 98*28, differing 

 considerably from the value used by Nernst for a different 

 purpose. 



In Landolt and Bornstein's Tabellen, the values of L for 

 Benzophenone are given as 23*7 (Bruner, Ber. ii. p. 2102, 



