THALLIUM ELECTRODE AND THALLOUS IODIDE. 



203 



TABLE II. 

 Conductivity of Thallous Nitrate Solutions at 0°C. 



First Series 



Density 



1.02344 

 1.01165 



(1.00458) 

 (1.00222) 

 (1.00104) 

 (1.00034) 

 (1.00010) 



Wt. Nor- 

 mality 



0.097704 



0.04944 



0.04944 



0.019909 



0.009978 



0.004995 



0.001999 



0.0009999 



Vol. Nor- 

 mality 



0.09999 



0.05002 



0.05002 



0.02000 



0.01000 



0.005000 



0.002000 



0.001000 



Specific 

 conductivity 

 K observed 



0.0064801 



0.0034680 



0.0034683 



0.0014781 



0.00076408 



0.00039125 



0.00015991 



0.000081008 



Water 

 correc- 

 tion 

 KxlOs 



0.47 

 0.44 

 0.44 

 0.59 

 0.48 

 0.35 

 0.31 

 0.36 



K corrected 



0.0064796 



0.0034676 



0.0034679 



0.0014775 



0.00076360 



0.00039090 



0.00015960 



0.000080647 



64.80 

 69.33 

 69.335 



73.875 



76.36 



78.18 



79.80 



80.65 



Second Series 



0.09771 



0.04942 



0.019909 



0.009978 



0.004993 



0.001999 



0.0009999 



0.10000 



0.05000 



0.0200C 



0.01000 



0.004998 



0.002000 



0.001000 



0.0064787 



0.0034659 



0.0014779 



0.00076383 



0.00039073 



0.00015960 



0.000080648 



64.79 

 69.32 

 73.90 

 76.38 

 78.18 

 79.80 

 80.65 



Extrapolation to infinite dilution, using the method of Noyes ^ 

 both graphically and algebraically (method of least squares), gave the 

 following results : 



25° 



148.974 

 148.938 



148.96 



Mean 



82.51 



According to Noyes and Falk ^^ the mobility of the nitrate ion at 25° 

 is 70.6 mhos and at 0° is 40.7 mhos; hence the mobility of the thallous 

 ion at 25°C. is 78.4 and at 0°C. is 41.8. 



9 See G. A. Abbott and W. C. Bray, Jour. Amer. Chem. Soc, 31, 745, and 

 John Johnston, ibid., 1010 (1909); and A. A. Noyes, Carnegie Institution Pub- 

 lication, No. 63 (1907). 



10 A. A. Noyes and K. G. Falk, Jour. Amer. Chem. Soc, 34, 479 (1912). 



