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  X. 
  The 
  Ionic 
  and 
  Thermal 
  Coefficients 
  of 
  Nitric 
  Acid. 
  By 
  

   V. 
  H. 
  Veley. 
  D.Sc, 
  F.R.S., 
  and 
  J. 
  J. 
  Manley, 
  Daubeny 
  

   Curator, 
  Magdalen 
  College, 
  Oxford*. 
  

  

  IN 
  a 
  former 
  investigation 
  t 
  we 
  have 
  published 
  determinations 
  

   of 
  the 
  electric 
  conductivity 
  of 
  nitric 
  acid 
  of 
  different 
  con- 
  

   centrations 
  at 
  the 
  three 
  temperatures 
  0°, 
  15°, 
  and 
  30° 
  C. 
  

   obtained 
  by 
  the 
  method 
  of 
  Kohlrausch 
  with 
  certain 
  modi- 
  

   fications. 
  It 
  has 
  for 
  some 
  time 
  been 
  noted 
  that 
  the 
  strong- 
  

   mineral 
  acids 
  do 
  not 
  follow 
  Ostwald's 
  dilution 
  law 
  

  

  i 
  ^w 
  = 
  K; 
  (1) 
  

  

  0*00— 
  **)>>„ 
  

  

  and 
  though 
  the 
  results 
  obtained 
  are 
  more 
  in 
  accordance 
  with 
  

   the 
  Rudolphi-van't 
  Hoff* 
  equation 
  

  

  ir-«pv 
  =K 
  ' 
  a= 
  y„' 
  • 
  • 
  • 
  • 
  (2) 
  

  

  yet 
  the 
  relation 
  can 
  only 
  be 
  regarded 
  as 
  empirical. 
  

  

  It 
  seemed, 
  therefore, 
  of 
  interest 
  to 
  calculate 
  from 
  our 
  con- 
  

   ductivity 
  determinations 
  the 
  amount 
  of 
  ionization 
  - 
  - 
  at 
  the 
  

  

  J 
  /*oo 
  

  

  different 
  percentage 
  concentrations 
  ; 
  for 
  though 
  results 
  for 
  

   dilute 
  samples 
  have 
  been 
  given 
  by 
  Kohlrausch 
  § 
  and 
  others, 
  

   yet 
  no 
  data 
  have 
  been 
  published 
  for 
  more 
  concentrated 
  

   samples. 
  The 
  value 
  for 
  the 
  molecular 
  conductivity 
  at 
  infinite 
  

   dilution 
  or/^ 
  oo 
  =Kl0 
  7 
  , 
  according 
  to 
  the 
  data 
  of 
  Kohlrausch 
  

   is 
  K 
  18 
  = 
  342, 
  or 
  K 
  15 
  = 
  325'4 
  when 
  reduced 
  by 
  the 
  formula 
  

  

  A*i5=/*i 
  8 
  342(H--0162[15-18]). 
  ... 
  (3) 
  

  

  In 
  the 
  following 
  Table 
  values 
  are 
  given 
  : 
  in 
  column 
  I. 
  the 
  

   percentage 
  concentration, 
  in 
  II. 
  the 
  corresponding 
  molecular 
  

   dilution, 
  in 
  III. 
  the 
  values 
  for 
  /j, 
  x 
  10 
  7 
  , 
  and 
  in 
  IV. 
  the 
  values 
  

  

  for 
  — 
  , 
  the 
  quotient 
  of 
  ionization. 
  

  

  ^* 
  QO 
  

  

  It 
  will 
  be 
  observed 
  that 
  there 
  is 
  an 
  irregularity 
  in 
  the 
  

   results 
  for 
  the 
  samples 
  from 
  98 
  per 
  cent, 
  to 
  100 
  per 
  cent., 
  

   which 
  is 
  consequent 
  upon 
  a 
  reversal 
  in 
  the 
  conductivity 
  

   values 
  ; 
  and 
  in 
  our 
  work 
  mentioned 
  above 
  attention 
  was 
  drawn 
  

   not 
  only 
  to 
  this 
  point, 
  but 
  also 
  that 
  whereas 
  nitric 
  acid 
  behaves 
  

  

  * 
  Communicated 
  by 
  the 
  Authors. 
  

  

  t 
  Phil. 
  Trans. 
  1898, 
  A. 
  p. 
  365. 
  

  

  X 
  Zeits.f.jjhysitol 
  Cheni. 
  xvii. 
  p. 
  385 
  (1895), 
  and 
  xviii.p. 
  301 
  (1895). 
  

  

  § 
  Wied. 
  Ann. 
  xxvi. 
  p. 
  196 
  (1885). 
  

  

  