ON ELECTROLYTIC CONDUCTIVITY IN CONCENTRATED SOLUTIONS. 255 



and for comparison the graph as interpolated by means of equation (2). Greater 

 certainty in interpolation is clearly one of the advantages gained. 



The Salts. 



The graphs for a number of the salts given in Table A are shown in fig. 3. As in 

 fig. 1 and fig. 4, the lines were calculated by equation (l), while the points indicate the 

 experimental values. The agreement is, generally speaking, most satisfactory. As a rule 

 the constant b is negative, so that A M increases with the dilution. It is remarkable 

 that in the case of KC1 the constant b is only— 1*067, so that A M varies very slightly 

 with varying concentration. In the case of KBr, KI, and NHJ the constant 6 is 

 positive, that is, A M decreases with dilution until a concentration of about 0*5 normal 

 is reached. In solutions of these and of all the other electrolytes A M rapidly increases 

 on further dilution, and from about 0*1 normal down to infinite dilution the graphs 

 practically coincide with those obtained by using the volume units. At a concentration 

 of about 0-3-0-5 normal the values for A, for the salts generally, approximate very 

 closely to the values for the constant a of equation ( 1 ). 



The Hydrates. 



The graphs for LiOH, NaOH, and KOH are shown in fig. 4. 



The data for LiOH and for NaOH are barely sufficient, but so far as they go, 

 they point to a similar regularity. The graph for KOH is rectilinear over a very 

 wide range of concentration, viz. from 1'612 normal to 10'695 normal, and the differ- 

 ences between the observed and calculated values for the five points given within this 

 range in no case exceed ] per cent., while for a concentration of 0*777 normal the 

 difference is only + 1*6 per cent. In the case of NaOH the agreement between the 

 experimental and the calculated values for A M is perfect for the three points from 0*641 

 to 2*779 normal and also for the interpolated point 4*381 normal. 



The only other point of higher concentration given, viz. that for 6*122 normal, is 10*5 

 per cent, out, so that the graph evidently becomes curved between 4*381 and 6'122 

 normal. 



The Strong Acids. 



The data for the haWen acids HC1, HBr, and HI are altooether insufficient. 



An investigation into the conductivity of these acids will be published shortly. 

 Meantime it may be stated provisionally that the determinations so far made show that 

 equation (l) applies over considerable ranges of concentration to HBr and HI, and 

 probably applies also in the case of HC1. The graphs for HNO s , |-H 2 S0 4 , and |H 3 P0 4 

 are shown in fig. 4. The graph for ^H 3 P0 4 is remarkable for the very small variation 

 in A M over a wide range of concentration. 



