SOLUTIONS AS A FUNCTION OF TEMPERATURE 147 



TABLE XLVIII. 

 CONDUCTANCE OF KC1 IN H 2 AT HIGHER TEMPERATURES. 



Concentration * 18 25 100 140 156 218 281 306 

 0.08 N. A 72.3 113.5 341.5 455 498 638 723 720 



0.002 N. A 79.6 126.3 146.4 393 534 588 779 930 1008 



It will be noted that at the higher concentration the conductance passes 

 through a maximum somewhere between 281 and 306. In the more 

 dilute solution, a maximum has not been reached below 306. This 

 behavior is quite general in aqueous solutions and is found also in non- 

 aqueous solutions. The lower the concentration, the higher the tem- 

 perature of the maximum. 



For solutions of sodium chloride, the conductance-temperature curve 

 is similar to that of potassium chloride, although for this salt the maxi- 

 mum has not been reached at 306, even at a concentration of 0.08 

 normal. We have seen that, with increasing temperature, the conduct- 

 ance of the sodium ion increases relatively more than that of the potas- 

 sium ion. As a consequence, the maximum in the conductance curve is 

 shifted to higher temperatures. In general, the higher the conductance 

 of the electrolyte, the lower the temperature of the maximum and the 

 lower the concentration at which the maximum will appear at a given 

 temperature. 



For silver nitrate, the maximum lies somewhat lower than it does for 

 potassium chloride, as may be seen from the following table: 



TABLE XLIX. 

 CONDUCTANCE OF AgN0 3 IN H 2 AT HIGH TEMPERATURES. 



Concentration t 18 100 156 218 281 306 



0.08 N A 96.5 294 432 552 614 604 



The lower temperature of the maximum for silver nitrate is due, partly, 

 to the abnormal manner in which the conductance of the nitrate ion 

 changes as a function of the temperature and, partly, to the more 

 rapid decrease in the ionization of silver nitrate with increasing tem- 

 perature. 



The higher types of salts exhibit maxima which are more pronounced 

 and which occur at lower concentrations and lower temperatures. In 

 Table L are given values for barium nitrate and magnesium sulphate at 

 0.08 normal. 



