76 



K. D. Kraevitch on an Approximate Law of the 

 Ethyl Chloride, C 2 H 5 C1. 



18. 



1st Method. 











t 



-15° 



-10° 



-5° 



0° 



25° 



X . 



10-48 



6-560 

 35° 



5-188 

 40° 



3-970 

 45° 



1-6209 



t 



30° 



65° 





1-4039 



1-3183 



1-3334 



1-3399 



1-8691 



The minimum of x lies at 35° and is equal to 1*3183: 

 hence, 



c-cx= 1-3183 x ^=0-040878. 

 64*5 



The specific heat c x is unknown. According to Regnault 

 c = 0*42760; hence Cl = 0-38672. 

 We then calculate y and r Q : 



y = 3000-24, 



r = 3000-24 x t£- k = 93-032. 

 64*5 



According to Regnault the heat of vaporization at the 

 atmospheric pressure is 89*30. 



2nd Method. 



t. 



p. 



dp 

 dt* 



t. 



JP- 



dp 

 dt' 



o 



20 



996-23 

 118417 

 1398-99 

 1643-24 



45820 

 51969 



o 



40 



1919-58 

 2230-71 

 2579-40 



58-656 



25 



45 



30 



50 



35 









c— <?, 



30° 35° 40° 



93*242 93-027 92'824 



0-215 0-203 



00430 00406 



The heats of vaporization determined by both methods 

 were alike 93*027 and 93-032. The values for c— c x were 

 also exceedingly near to each other. 



