Variation in the Pressure of Saturated Vapours. 69 



Carbon Tetrachloride, CC1 4 . 



13. 1st Method. 



t -15° -10° -5° 0° 5° 10° 15° 20° 



x 5-2217 6-4753 6-2296 6-5014 5-8202 6-8851 6-0289 6-2210 



t 25° 30° 35° 40° 70° 75° 125° 



x 5-9630 59526 6-3706 5-5984 4-4596 4*2927 11511 



The figures as we see proceed irregularly, but there is 

 hardly any doubt that the maximum lies at 10°. 



c~ Ci = 6*8851x-|t = 0-08942*. 

 1 154 



It is impossible to compare this figure with the result of 

 experiment, because the specific heat of the vapour of carbon 

 tetrachloride is not known. But it is possible to conversely 

 calculate this quantity, knowing c— c x and c. According to 

 Regnault c=0*19979, therefore ci==0-11037*. 



By equation (9) we obtain 



y •= 4061-3, 

 whence 



r =4061*3x -|r=52'069. 



According to Regnault r l0 — 51*45. 

 2nd Method. 



t 



P- 



dp 



dl' 



t. 



P- 



dp 



dt' 



o 

 __ 15 



13-55 

 18-47 

 24-83 

 32-95 



1-4371 

 1-8230 

 2-2870 

 2-8380 



o 



15 



71-73 



90-99 



114-30 



142-27 



175-55 



3-4842 

 4-2379 

 5-1070 



_ 10 



20 



— 5 



25 



. 



30 



5 



4319 

 55-97 



35 



10 





c— c 



-5° 0° 5° 10° 15° 20° 25° 



53-295 52-865 52-467 52-063 51654 51-264 50870 



0-430 0-398 0-404 0-409 0-390 0-394 



0-0860 0-0796 0-0808 0-0818 0*0780 00788 



* See Notes at end. 



