CONDUCTIVITY OF SODIUM HYDROXIDE IN AQUEOUS SOLUTION. 307 



tion of density and concentration, together with any errors in the adjustment of the 

 constants for a and n, are thrown upon the coefficient b. The accuracy of the 

 experimental work, and the validity of the formula for the influence of temperature 

 on conductivity, can then be tested (1) by comparing the two values of b deduced 

 from K M , K IOO respectively (Table XIX.), (2) by the smoothness or otherwise of 

 the curve representing the variation of b with the concentration of the solution 

 (Diagram XIV.). 



In Table XIX. are given the values of the coefficients for all the solutions referred to 

 in Table XV. The values of a and n are the values derived from the expressions 

 formulated above. The values for b are those derived from K 100 and K^. It will be 

 observed that in the column of differences for the b values, there is a progressive 

 series of positive differences followed by a series of negative differences. This is 

 mainly due to the fact that the slope of the line representing the variation with 

 concentration of the constant a was chosen so as to give the values for a at 40 per 

 cent, and at 4 per cent as close as possible to these individual values. A closer 

 agreement would have resulted if the linear relationship had been adjusted for 

 40 per cent, and 10 per cent., but the differences were so small that it was not 

 deemed necessary to repeat the somewhat tedious calculations involved. The values 

 of the constants are plotted out in Diagram XIV., and the smoothness of the 

 individual values for b is a satisfactory indication of the validity of the formula 

 employed. 



TABLE XIX Coefficients in the Equation 



Physical Meaning of the Coefficients. The formula used to represent the influence 

 of temperature on conductivity is of value not only because it gives us an exact 



2 R 2 



