1650 
Hydrogen ton concentration of N/,, succinic acid. 
Insertion of the normal cell; reading on the scale = 502.4 
EN „ concentration chain; ,, Baal ee ee 4 (al 
9 
EMF == RT < 1.0177 = 0.487. From this, see above 
0,487—0,337 
log Cr = = — 6010403 
0,059 
C—O Ozn 
The dissociation constant of succinic acid at 25° —= 6,3 «10°; 
from this follows, for the dissociation degree of a N/,, solution, 
from the relation 
a“ 
=x , a=—0.0248 hence Cyg-=— 0.00248 = 2.48 x 107°. 
(l—a)v ae 
Hydrogen-ion concentration of mannitol (0,5 mol.) 
Insertion of the normal cell; reading on the scale = 513. 
„ concentration chain; _ ,, Ae See 02s 
302 
EME = — X 1.0177 = 0.599. 
513 
e 0.599—0.377 
log Cy = — — 0.059 
Ud 
Cr = 3.7 X 107°. 
= — 4.443 = 0.567—5 
The specifie conductivity of the mannitol was higher than could 
be expected from a polybydroxy-compound, namely — in the case 
of a 0.5 mol. solution — = 32.4 x 10-6. 
If we suppose this to be in consequence of its acidic properties 
we get by calculation 
Cr Re Ten SS 0m 
380 —_———_——_ 
This is undoubtedly too high; presumably the mannitol was con- 
taminated with small quantities of acidic electrolytes. 
Hydrogen-ion concentration of 0.5 mol. mannitol + 0.5 mol. 
boric acid. 
Insertion of the normal cell; reading on the scale = 511. 
concentration chain; EA Sure Dn 24 
DE) ” LE) 
241 . . 
EMF — maa 1.0177 = 0.480 v 
o 
