Ill 



only of a qualitative nature. To both cases applies 

 the equation: 



(Amount of free acid) (Amount of free base) = 

 K (Amount of combined base) 2 . 



In the case of the strong acids and the strong bases 

 (or even NH 3 ) K is = = 0, perhaps more correctly excee- 

 dingly small. It follows from this that either the 

 amount of free acid or the amount of free base is ex- 

 ceedingly near 0, viz. a strong acid and a strong base 

 cannot exist in perceptible amounts in the same solu- 

 tion. It is quite another matter when K has a definite 

 value, f. inst. 1, as it is closely the case, when bora- 



Fig. 6. 



cic acid combines with ammonia. If (n 1) equivalents 

 of acid be added to 1 equivalent of ammonia, then 1/n 

 of ammonia will always remain free, because: 



1 ) ( n _i n_J-\ I n -) a 



n }( n'f ' ~n' 



It appears that if one equivalent of boracic acid is 

 added, then the half of the base is free, if two equiva- 



