PHYSICAL PROPERTIES OF FATTY ACIDS 59 



When one considers the sohibihty of water in the fatty acids, the varia- 

 tions between caproic and stearic acid are much less marked and the 

 temperature effects are considerably less pronounced than are noted in re- 

 gard to solubilities of the fatty acids in watei'. In all cases the amoimt of 

 water retained in the fatty acid is markedly greater than the quantity of 

 fatty acid dissolved in water. Data on these studies of Hoerr et al.--^ 

 are recorded in Table 21. 



b. Solubility of Saturated Fatty Acids in Non-aqueous Solvents. 

 The solubilities of the saturated fatty acids in such non-acjueous solvents 

 as benzene, cyclohexane, ethanol, and isopropanol are summarized in 

 Tables 22 to 25, as well as in Figures 3 to 6. Ralston and Hoerr reported 



Table 22 

 Solubility of Saturated Fatty Acids in Benzene" 



Grams acid dissolved per 100 grams benzene at 

 Name of No. of 



acid C atoms 10° 20° 30° 40° 50° 60°C. 



Caprj'lic 8 770 co oo oo oo oo 



Pelargonic 9 2680 oo oo oo co oo 



Capric 10 145 398 8230 oo oo oo 



Undecanoic 11 208 663 oo <» oo od 



Laurie 12 32.3 93.6 260 1390 



Tridecanoic 13 42.4 117 354 7600 



Myristic 14 6.95 29.2 87.4 239 1290 



Pentadecanoic 15 8.84 36.2 103.0 295 2280 



Palmitic 16 1.04 7.30 34.8 105 306 2170 



Margaric 17 1 .52 9.23 42. 1 121 369 5450 



Stearic 18 0.24 2.46 12.4 51 145 468 



" A. W. Ralston and C. W. Hoerr, /. Org. Chem., 7, 546-555 (1942), p. 552. 



Table 23 

 Solubility of Satur.\ted Fatty Acids in Cyclohexane" 



Grams acid dissolved per 100 grams cycloliexane at 

 Name of No. of 



acid C atoms 10° 20° 30° 40° 50° 60°C. 



Caprylic 8 670 oo oo oo oo oo 



Pelargonic 9 2340 co oo oo oo co 



Capric 10 103 342 7600 co co oo 



Undecanoic 11 150 525 oo oo od oo 



Laurie 12 19.8 68 215 1310 



Tridecanoic 13 31.0 100 330 8200 



Myristic 14 5.3 21.5 72.0 217 1310 



Pentadecanoic 15 6.8 27.1 88.0 277 2460 , oo 



Palmitic 16 0.9 6.5 27.4 92.0 285 2530 



Margaric 17 1.5 8.4 34.0 108 365 7600 



Stearic 18 0.2 2.4 10.5 43.8 133 450 



" C. W. Hoerr and A. W. Ralston, J. Org. Chem., 9, 329-337 (1944), p. 330. 



"1 C. W. Hoerr, W. O. Pool, and A. W. Ralston, Oil & Soap, 19, 126-128 (1942). 



