Freezing -'points of Solutions of Water in Formic Acid. 1 9 



Using this formula, we can calculate the freezing-points 

 for the solutions employed, and we get : — 



Freezing-points. 



Calculated. 



"A 



Observed. 



Difference. 



7-61 



7-69 



-0-08 



7-26 



7-29 



-0-03 



6-98 



7-00 



-0-02 



6-01 



G-10 



-0-09 



5 -28 



541 



-0-13 



4-61 



4'71 



-0-10 



4-20 



4-35 



-0-15 



3-G8 



3-87 



-0-19 



8-41 



3-60 



-0-19 



3-17 



3-41 



-0-24 



2- CO 



2-91 



-•031 



1-87 



2-21 



-0-34 



1-15 



1-60 



-0-45 



-1-15 



-O40 



-0-75 



-3-80 



-1-81 



—1-99 



The increasing differences between calculated and observed 

 values for the freezing-points show clearly that proportionality 

 between depression in freezing and concentration measured 

 in number of gram-molecules per litre only holds for dilute 

 solutions, which of course could be seen from the diagram 

 (fig. 3) and equation (3), which shows the proportionality 

 between depression in freezing-point and concentration mea- 

 sured in per cents, of water. Putting then for p its value in ?n, 



1801 m , 



1223 + 18-01 m' 



we can calculate the value ef 1*537 

 ferent values of m. 

 We get :— 



1801 



1223 + 18-01 m 



for dif- 



1-537 



1801 



1223+18-01 m 



2-263 

 2-260 

 2-230 

 2-198 

 2-168 

 2-13J 

 2-108 



Results 



-Formic acid, if it dissolves a small quantity of 

 C2 



