﻿Van 
  Name 
  and 
  Hill 
  — 
  Alcohol 
  and 
  Cane 
  Sugar. 
  543 
  

  

  Art. 
  XLYIIT. 
  — 
  On 
  the 
  Influence 
  of 
  Alcohol 
  and 
  of 
  Cane 
  

   Sugar 
  upon 
  the 
  Bate 
  of 
  Solution 
  of 
  Cadmium 
  in 
  Dissolved 
  

   Iodine 
  / 
  by 
  R. 
  G. 
  Van 
  Name 
  and 
  D. 
  U. 
  Hill. 
  

  

  [Contributions 
  from 
  the 
  Kent 
  Chemical 
  Laboratory 
  of 
  Yale 
  Univ. 
  — 
  ccli.] 
  

  

  It 
  has 
  been 
  showii 
  by 
  Arrhenius* 
  that 
  the 
  effect 
  of 
  the 
  pres- 
  

   ence 
  of 
  certain 
  non-electrolytes 
  upon 
  the 
  rate 
  of 
  diffusion 
  of 
  

   electrolytes 
  may 
  be 
  represented 
  by 
  the 
  empirical 
  equation 
  

  

  D 
  = 
  D.(l--?m)', 
  

  

  in 
  which 
  D 
  is 
  the 
  diffusion 
  coefficient 
  of 
  the 
  electrolyte 
  in 
  

   solution 
  in 
  pure 
  water, 
  D 
  the 
  coefficient 
  after 
  the 
  addition 
  of 
  

   the 
  non-electrolyte, 
  m 
  the 
  molecular 
  concentration 
  of 
  the 
  latter, 
  

   and 
  a 
  a 
  constant 
  characteristic 
  of 
  the 
  non-electrolyte. 
  When 
  

   the 
  value 
  of 
  a 
  is 
  known, 
  we 
  may 
  employ 
  this 
  relation, 
  as 
  Jabl- 
  

   czynskyf 
  has 
  pointed 
  out, 
  to 
  test 
  the 
  dependence 
  of 
  a 
  given 
  

   heterogeneous 
  reaction 
  upon 
  the 
  rate 
  of 
  diffusion 
  of 
  a 
  dissolved 
  

   electrolyte, 
  and 
  thus 
  obtain 
  a 
  test 
  of 
  the 
  validity 
  of 
  the 
  " 
  dif- 
  

   fusion 
  theory 
  " 
  in 
  the 
  given 
  case. 
  Since 
  the 
  diffusion 
  theory 
  

   calls 
  for 
  proportionality 
  between 
  the 
  reaction 
  velocity 
  and 
  the 
  

   rate 
  of 
  diffusion 
  of 
  the 
  active 
  substance,;}; 
  the 
  effect 
  of 
  a 
  non- 
  

   electrolyte 
  upon 
  the 
  reaction 
  velocity 
  should 
  be 
  calculable 
  by 
  

   substituting 
  in 
  the 
  above 
  equation 
  the 
  reaction 
  velocities 
  K 
  and 
  

   K 
  in 
  place 
  of 
  the 
  corresponding 
  diffusion 
  coefficients. 
  

  

  In 
  a 
  study 
  of 
  the 
  catalysis 
  of 
  chromous 
  chloride 
  at 
  the 
  sur- 
  

   face 
  of 
  a 
  sheet 
  of 
  platinum, 
  Jablczynsky 
  showed 
  that 
  the 
  

   observed 
  effect 
  of 
  ethyl 
  alcohol 
  upon 
  the 
  reaction 
  velocity 
  

   agreed 
  with 
  that 
  calculated 
  as 
  above, 
  using 
  the 
  value 
  of 
  a 
  

   determined 
  by 
  Arrhenius. 
  Later, 
  the 
  same 
  author, 
  working 
  

   with 
  Jablonski,§ 
  obtained 
  a 
  similar 
  result 
  for 
  the 
  effect 
  of 
  

   alcohol 
  upon 
  the 
  rates 
  of 
  solution 
  of 
  magnesium 
  and 
  of 
  marble 
  

   in 
  aqueous 
  hydrochloric 
  acid. 
  The 
  reaction 
  velocity 
  was 
  

   determined 
  in 
  all 
  of 
  these 
  cases 
  by 
  measuring 
  the 
  volume 
  of 
  

   gas 
  evolved. 
  

  

  In 
  previous 
  papers 
  from 
  this 
  laboratory! 
  it 
  has 
  been 
  shown 
  

   that 
  the 
  metals 
  Hg, 
  Cu, 
  Ag, 
  Zn, 
  Cd, 
  Fe, 
  Si, 
  and 
  Co, 
  all 
  dis- 
  

   solve 
  at 
  the 
  same 
  rate 
  in 
  a 
  solution 
  of 
  iodine 
  in 
  potassium 
  

   iodide, 
  thus 
  indicating 
  that 
  the 
  diffusion 
  of 
  the 
  iodine, 
  presum- 
  

   ably 
  in 
  the 
  form 
  of 
  potassium 
  triiodide, 
  is 
  the 
  determining 
  

  

  *Zeitschr. 
  phys. 
  Chem., 
  x, 
  51, 
  1892. 
  

  

  flbid., 
  lxiv, 
  748, 
  1908. 
  

  

  % 
  This 
  is 
  strictly 
  true 
  only 
  when 
  the 
  thickness 
  of 
  the 
  diffusion 
  layer 
  

   remains 
  unchanged. 
  

  

  gZeitschr. 
  phys. 
  Chem., 
  Ixxv, 
  503, 
  1910. 
  

  

  I 
  Van 
  Name 
  and 
  Edgar, 
  this 
  Journal, 
  (4), 
  xxix, 
  237 
  ; 
  Van 
  Name 
  and 
  Bos- 
  

   worth, 
  this 
  Journal, 
  (4), 
  xxxii, 
  207. 
  

  

  