lo4 Van Name and Huff -Hydrolysis and Electrical 



is simplified by the fact that the reaction can be stopped 

 at will, what ever the temperature of experiment, by 

 neutralizing with an alkali. Although in measuring the 

 rate of this hydrolysis we have employed a method of 

 analysis which calls for a brief period of low acidity, the 

 further hydrolysis which occurs during this interval is 

 so slight that the error thus introduced is insignificant. 

 Procedure. — For the experiments at 25° the reaction 



Table I. ' 



Rate of Hydrolysis of Hypophosphoric Acid at 25°. 

 Hypophosphate solution approx. N/20 ILNaJPX),,. 



1. Eeaction mixture: 



Equal vols. 









hypophosphate sol 



, and HC1 of 



2. Equal 



vols, hypoph 



osphate sol. 



sp. grav. 1-173. 





and I-IC1 sp. grav. 1-185. 



Elapsed 



Thiosul- 





Elapsed 



Thiosul- 





time 



phate 



K 



time 



phate 



K 



min. 



em 3 





min. 



cm 8 









48-18 









4615 





900 



46-68 



000105 



87-3 



43-70 



000126 



225-3 



44-77 



000102 



232-7 



40-28 



0-00124 



357-3 



4310 



000102 



353-6 



37-81 



0-00124 



7080 



39-52 



000104 



484-2 



35-55 



000124 



1293 



35-98 



000103 



588-1 



33-95 



000125 





(31-52 

 (31-57 





743-6 



31-96 



000125 



00 





1385 



26-95 



000124 











(22-70 

 J22-73 











CO 











4. One vol. HC1, sp. 



grav. 1185 



3. Equal 



vols, hypophosphate sol. 



made 



up to 4 vols. 



with hypo- 



and 



HC1 of sp. 



grav. 1185. 



phosphate sol. 





Elapsed 



Thiosul- 





Elapsed 



Thiosul- 





time 



phate 



K 



time 



phate 



K 



min. 



cm' 





min. 



em 3 









4606 









42-85 





59-8 



44-37 



000125 



877-1 



37-90 



0-000187 



197-6 



40-93 



000125 



2135 



32-18 



0000185 



3180 



38-37 



000125 



2821 



29-55 



0000186 



449-7 



3604 



000124 



3558 



2700 



0-000187 



707-7 



32-23 



000126 



4335 



24-92 



0000184 



1339 



2706 



0-00124 



5759 



21-53 



0000184 



1630 



25-68 



000125 



7176 



18-67 



0000188 



cc 



22-65 





9245 



CO 



15-89 



10-20* 



0000189 



* Calculated from standards of solutions used. 



