MOLECULAR CONDUCTIVITY OF AMIDOSULPHONIC ACID. 265 



The molecular conductivity of sodium amidosulphonate is, 

 therefore, 



It may be observed that the difference jtt 1024 —/%= 10.26 is of the 

 same magnitude as that in the case of the sodium salts of all the 

 monobasic acids, showing that the ions of amidosulphonic acid are 

 H and NH 2 S0 3 . For calculating the molecular conductivity of 

 sodium amidosulphonate at infinite dilution I have made use of 

 Bredig's table (Zeit, plujsik. Chan., 13, 198 [1894]), which gives a 

 more concordant result than the use of Ostwald's values. 



v = 32 64 128 256 512 1024 



d v = 14 11 8 6 4 3 



H„ = 84.25 87.79 90.52 92.04 93.90 94.51 



^=98.25 98.79 98.52 98.04 97.90 97.51 Mean 98.17. 



The velocity of migration of IVrt-ion being 49.2, that of the 

 NH 2 S0 3 -ion is 98.17 — 49.2 = 48.97 ; and the velocity of migration of 

 H-ion being 325, the molecular conductivity of amidosulphonic acid 

 at infinite dilution, p œ , is evidently 325 + 48.97=373.97. 



Discussion of the results. The velocity of migration of the anion 

 NH 2 S0 3 = 48.97 approaches those of LVO 3 =50.5 and F=50.8 ; it is 

 much greater than that of J() 3 =37.9 or H 2 PO i =oo.5, and much less 

 than that of C/ = 70.2, LV = 73.0, 1=72.0, or M) 3 =65.1. Among 

 the organic anions that of formic acid, HC0 2 = 51.2, is the only one 

 which exceeds NH 2 S0 3 in velocity. 



