﻿4 Mr. W. Sutherland on the Molecular 



But from (3) and (4), 



v n = l/{ l + 0-2856> 4 E/e + 7i (P + N)}, 

 where E is the equivalent mass of NH 4 C1. 



.-. Vn =l-p 4 {0-2856EA + 10 3 (P + N)/4 approx. . (9) 

 Comparing (8) and (9) we have 

 T={(l-t7 4 >-0-2856E-10 3 (P + N)}/54(t; 1 -w a ). . (10) 



In this expression v±e is the volume o£ a gramme equivalent 

 of the solute, which for most electrolytes is the sum of parts 

 due to each ion, e is the sum of such parts, as is also P + N. 

 Therefore (10) contains the rather important result that the 

 number of molecules of (H 2 0) 3 dissociated by an equivalent 

 of solute is the algebraic sum of parts due to its positive and 

 negative ions and a part 0*2856E/54(v 1 — v 2 ), whose apportion- 

 ment to positive and negative ions will be discussed im- 

 mediately. Its value is — 1*29, of which we suppose — 1*29 + x 

 and —1*29+3/ to belong to the positive and negative ions. 



We shall now tabulate the data requisite for the calculation 

 of t by (10) and the parts of t due to each ion together with 

 — 1*29 + .7? or — 1*29 +y. The parts of v±e due to each ion 

 are obtainable from u Further Studies on Molecular Force " 

 (Phil. Mag. [5] xxxix. 1895, pp. 15, 24, 26, 31), where they 

 are denoted by B for the whole gramme atom ; P and N from 

 Bender (loc. cit.). As e is the usual equivalent weight, it is 

 not tabulated. 



E = 18 + 35-4, ^ = 0-9179, v 2 =1-1364. 



These are the values of v 1 and v 2 at 0°, the latter not being 

 accurate enough to make it worth while correcting for 18°. 



Table I. 



Li. Na. K. NH 4 . Mg. Ca. Sr. Ba. Zn. Ccl. Pb. Ag. 



V 2-0 7-4 18-6 180 28 4-3 53 83 53 6-25 49 68 



!0 3 P 7-7 23-5 29-6 22'1 28-2 52-2 739 410 606 109 1'07 



7— 129+*... 023 067 0'7S 109 1-06 116 1-14 116 0-91 088 0-49 



r 152 1-96 2-07 1-29 2"38 2-35 2-45 243 2-45 2-20 2-17 178 



CI. Er. I. N0 3 . S0 4 . C0 3 . CH 3 COO. 



v 4 e 19 26 36 31 " 17 13 42 



10 3 N 37 73-3 16 20 14 -15 



r-l-29+y -1-39 -1-44 -1-50 -127 -0-93 -0-25 -1-57 



t -1-39 -1-44 -1-50 -1-27 -093 -025 -157 



