542 Mr. W. J. Young. Hexosephosphate formed by [July 30, 



Table XIV. — Glycerophosphoric Acid. 



Time, in minutes. 



Rotation. 





.A. — x. 



K x 10 4 . 



u 



. no .o£ 

 + Zo OD 



u 



o4 41 





o± 



60 01 



u oo 



OO OO 



o OUo 



fif\ 

 DU 



a a *tjQ 



/y 



1 at 



qo ,Q A 



oZ o4) 



3 '380 



90 



24 -06 



2-30 



32 -11 



3-338 



120 



23 -30 



3 '06 



31 -35 



3 -370 



150 



22-64 



3-72 



30 -69 



3 -312 



182 



21 -86 



4-50 



29 -91 



3. -344 



210 



21 -23 



5-13 



29-28 



3-339 



240 



20-54 



5-82 



28 -59 



3-353 



270 



19 -89 



6-47 



27 -94 



3 -350 



300 



19 -26 



7-10 



27 '31 



3-345 



330 



18 -64 



7-72 



26 -69 



3-343 



360 



18-01 



8-36 



26-05 



3 -358 



CO 



-8-05 



34 -41 













Mean 



3 "353 



Semi-normal hydrochloric acid under the same conditions gave the constant 

 K x 10 4 = 22-46 6. 



It follows from these rates that the ratio of hydrogen ions in the solution 

 of hexosephosphoric acid to those in the hydrochloric acid was 3 - 981 to 

 22-466 or 17*7 to 100, whilst in the case of glycerophosphoric acid the ratio 

 was 3-353 to 22*466 = 14 - 9 to 100. As hydrochloric acid is almost completely 

 dissociated, these numbers may be taken as a measure of the concentration of 

 hydrogen ions in the solutions. < Glycerophosphoric acid is dibasic and a 

 solution which is semi-normal by titration will contain only half as many 

 molecules as a semi-normal solution of hydrochloric acid, or 50 molecules for 

 every 100 of hydrochloric acid. If the glycerophosphoric acid be assumed to 

 dissociate into two ions, then out of every 50 molecules 14 - 9 are dissociated 

 into 14-9 x 2 = 29 - 8 ions, and 50 — 14 - 9 = 35-1 molecules remain undissociated. 

 The solution will thus contain 29-8 + 35*1 = 64 - 9 units, and the freezing point 



50 



depression will correspond to a molecular weight of — — x 172 = 132 - 5 ; those 



actually observed gave 135 - 5 and 127'7. Similarly with the hexosephosphoric 

 acid, if the larger formula obtain, the acid is tetrabasic and a semi-normal 

 solution will only contain one-quarter as many molecules as a semi-normal 

 solution of hydrochloric acid, or 25 molecules to every 100 of hydrochloric 

 acid. If the dissociation take place into two ions, of these 25 molecules 

 17"7 are dissociated into 17'7 x 2 = 35-4 ions, 25 — 17 - 7 = 7'3 molecules remain 

 undissociated, and the total number of units will be 7'3 + 35 - 4 = 42 - 7. The 

 molecular weight of the acid from the freezing point of this solution will be- 



= 199 ; the observed values were 177, 178, and 169"4. 



42:7 . . 



