86 PROPERTIES OF ELECTRICALLY CONDUCTING SYSTEMS 



a given rise in the curve above the value of K, the ion concentration will 

 be the smaller, the smaller the value of ra. The value of the ion concen- 

 trations corresponding to any given value of K f are found by drawing a 

 horizontal line and reading off the concentrations at the points of inter- 

 section. In Table XXXI are given the values of ra, D/K, and the ion 



TABLE XXXI. 



VALUE OF D/K AND OF ra AND CONCENTRATIONS AT WHICH GIVEN DEVIA- 

 TIONS FROM THE MASS- ACTION LAW OCCUR FOR SOLUTIONS IN NH 3 . 



; 



Electrolyte D/K X 10- 2 m K '~ K ~ 



A A 



CX10* CyXlQ 4 CX10 4 



KNH 2 ............. ........ 7.91 1.18 2.76 8.82 8.97 65.0 



Agl ........................ 0.345 0.70 0.86 1.14 6.38 18.03 



NH 4 C1 ............ . ...... . . 1.06 0.84 1.10 1.19 5.70 7.99 



KN0 3 ...................... 1.35 0.89 1.35 1.46 6.89 10.80 



NaN0 3 .................... 1.39 0.89 1.33 1.42 6.52 8.06 



NH 4 Br .............. : ...... 1.04 0.82 0.89 0.92 4.85 5.70 



LiN0 3 ..................... 1.31 0.86 1.06 1.10 5.33 6.32 



Nal ....................... 1.54 0.83 0.63 0.64 3.33 3.66 



AgN0 3 ..................... 1.29 0.83 0.78 0.80 3.38 3.80 



NH 4 N0 8 .................... 1.39 0.86 0.98 1.02 4.92 5.64 



KI ........................ 1.43 0.94 2.03 2.12 8.91 10.50 



Cyanacetamide .............. 55.8 1.24 0.83 15.4 2.53 120.0 



Benzenesulphonamide ........ 2.09 1.00 2.40 6.34 9.59 64.8 



Methylnitramine ............ 0.941 0.85 1.32 1.52 7.08 12.04 



Metanitrobenzenesulphonamide 0.825 0.76 0.58 0.61 3.62 4.49 



Nitrourethaneammonium ..... 1.02 0.76 0.44 0.45 2.74 3.03 



Trinitraniline ............... 1.27 0.73 0.22 0.22 1.45 1.49 



concentrations Cy and the total salt concentrations at which the increase 

 over the values of K amounts to 5 and 20 per cent respectively. 



For approximately the same value of D/K the value of Cy, for which 

 a given increase occurs in the value of the mass-action function, decreases 

 as m decreases. Thus, in the case of benzenesulphonamide, methyl- 

 nitramine, metanitrobenzenesulphonamide, and trinitraniline, the value of 

 m decreases from 1.0 to 0.73, while the value of Cy for a 5% increase in 

 the function decreases from 2.40 to 0.22. Similarly, in the case of sodium 

 and potassium iodides, the values of ra are respectively 0.83 and 0.94, 

 and the values of the ion concentrations for a 5% increase in the func- 

 tion are 0.63 and 2.03 respectively. The deviations from the simple 

 mass-action law, at a given concentration therefore appear smaller in the 

 case of potassium iodide than in that of sodium iodide. For the same 



