TABLES 407-415.— ELECTROLYTIC CONDUCTION 



397 



TABLE 407.— CONDUCTIVITY OF ELECTROLYTIC SOLUTIONS 



In these tables m represents the number of gram molecules to the liter of water in the 

 solution for which the conductivities are tabulated. The conductivities were obtained by 

 measuring the resistance of a cell filled with the solution by means of a Wheatstone bridge 

 alternating current and telephone arrangement. The results are for 18°C, and relative to 

 mercury at 0° C, the cell having been standardized by filling with mercury and measuring 

 the resistance. They are supposed to be accurate to within one percent of the true value. 



The tabular numbers were obtained from the measurements in the following manner : 



Let Ki* = conductivity of the solution at 18°C relative to mercury' at 0°C. 

 K w n = conductivity of the solvent water at 18°C relative to mercury at 0°C. 



Then Km — A' K i S = k is = conductivity of the electrolyte in the solution measured. 



— =n = conductivity of the electrolyte in the solution per molecule, or the 

 m 



"specific molecular conductivity." 



Part 1. — Value of k ls for a few electrolytes 



This short table illustrates the apparent law that the conductivity in very dilute solutions 

 is proportional to the amount of salt dissolved. 



Part 2. — Electrochemical equivalents and normal solutions 



The following table of the electrochemical equivalent numbers and the densities of ap- 

 proximately normal solutions of the salts quoted in Table 409 may be convenient. They 

 represent g per cm 3 of the solution at the temperature given. 



Salt dissolved g per 1 



KG 74.59 



NH«C1 53.55 



NaCl 58.50 



LiCl 42.48 



4BaCl 2 104.0 



iZnCU 68.0 



KI 165.9 



KNO3 101.17 



NaNO, 85.08 



AgNOi 169.9 



±Ba(NO,)» .. 65.28 



KCIO, 61.29 



KC 2 H 3 2 ... 98.18 



TABLE 408.— TEMPERATURE COEFFICIENTS OF CONDUCTIVITY 



The temperature coefficient in general diminishes with dilution, and for very dilute solu- 

 tions appears to approach a common value. The following table gives the temperature 

 coefficient for solutions containing 0.01 gram molecule of the salt. 



Temp. 

 Salt coeff. 



KCI 0221 



NHX1 0226 



NaCl 0238 



LiCl 0232 



iBaCU 0234 



iZnCli 0239 



iMgCl, 0241 



Temo. 

 Salt coeff. 



±K,CO, 0249 



*Na,CO. ... .0265 



KOH 0194 



HC1 0159 



HNO. 0162 



iHjSO, 0125 



for m — .0011 my * 



SMITHSONIAN PHYSICAL TABLES 



