Chemical Affinity. 



199 



exerted between the corresponding base and acid. By deve- 

 loping the Table in a third direction in space, expression might 

 be given to the influence of temperature upon the absolute 

 affinity (which influence is yet to be determined). The fact 

 that temperature is without influence upon the relative affinity 

 means only that the influence of temperature upon the abso- 

 lute affinity is the same for all compounds of acid and base. 



In his third paper Ostwald extends his researches upon the 

 neutralization of acids by bases. The following Tables con- 

 tain the principal results. 



The + sign denotes expansion of volume, the — sign con- 

 traction ; the numbers in brackets [ ] express the differences 

 between the sums of the coefficients of refraction of the acids 

 and bases, determined separately, and the coefficient of re- 

 fraction of the solutions formed on mixing these. The + sign 

 indicates an increase, the — sign a decrease in the coefficient 

 of refraction. The determinations of refraction-coefficients 

 were made at 20°, the sodium light being employed. 



Table VIII. 

 Neutralization of Monobasic Acids. 



Potash. 



Soda. 



■Ammonia. 



Nitric acid 



Hydrochloric acid ., 

 Hydrobroniic acid .. 



Hydriodic acid 



Formic acid 



Acetic acid 



Monochloracetic acid 

 Dichloracetic acid .. 

 Trichloracetic acid .. 



Propionic acid 



Butyric acid - 



Isobutyric acid 



Glycollic acid 



Lactic acid 



+20-046 

 +19-521 

 +19-626 

 + 19-799 

 +12-361 

 + 9-522 

 + 10-855 

 + 12946 

 +17-357 

 + 7-830 

 + 6-984 

 + 6-301 

 + 9-616 

 + 8-267 



[-897] 



"-882] 



-916] 



[-938] 



[-484] 



[-363] 



[-425] 



"-552] 



-774] 



-318] 



-279] 



-254] 



C - ] 



;-353] 



+ 19-770 [- 

 + 19-238 [■ 

 +19-336 [- 

 + 19-335 [- 

 +12-153 [- 

 + 9-287 [- 



+ 10628 

 + 12-702 

 + 17-067 



7-679 

 6-844 

 6-174 

 9-517 

 8-133 



886] 



879" 



907 



923 



478 



354 



412 



544 



774] 



306" 



269" 



24S" 



-344 : 



- 6-441 [+139 



- 6-572 [ + 148 



- 6-567 [+117] 



- 6-442 [+100 = 

 -13-593 [ + 536" 

 -16-261 [ + 646 : 

 -15-087 [ + 603] 

 ■12-975 [+473" 



- 8-665 [ + 264' 

 •17-822 [+699 : 

 ■18-633 [+730 : 

 •19-270 [ + 758 : 

 16-496 [ - 

 17-739 L+66L 



If the values which the same acids give with different bases 

 be considered, it is found that they are always positive [nega- 

 tive] for potash and soda, and always negative [positive] for 

 ammonia. The two following Tables contain the differences 

 between the numbers obtained by neutralizing the same acid 

 with two different bases, and the differences between the 

 numbers obtained by neutralizing different acids with the same 

 base. 



From these results it is seen that, the differences between 

 the numbers found for any two bases are nearly constant through" 



P2 



