﻿Gooch 
  and 
  Gruener 
  — 
  Determination 
  of 
  Antimony, 
  etc. 
  213 
  

  

  Art. 
  XIX. 
  — 
  A 
  method 
  for 
  the 
  Determination 
  of 
  Antimony 
  

   and 
  its 
  condition 
  of 
  Oxidation 
  ; 
  by 
  F. 
  A. 
  G-ooch 
  and 
  

   H. 
  W. 
  Gruener. 
  

  

  [Contributions 
  from 
  the 
  Kent 
  Chemical 
  Laboratory 
  of 
  Tale 
  College. 
  — 
  VIII.] 
  

  

  Bunsen's 
  method 
  of 
  determining 
  qualitatively 
  the 
  condi- 
  

   tion 
  of 
  oxidation 
  of 
  salts 
  of 
  antimony, 
  by 
  boiling 
  these 
  sub- 
  

   stances 
  in 
  solution 
  with 
  potassium 
  iodide 
  and 
  hydrochloric 
  

   acid 
  and 
  noting 
  whether 
  the 
  liquid 
  takes 
  the 
  color 
  of 
  free 
  

   iodine, 
  has 
  been 
  applied 
  successfully 
  to 
  the 
  quantitative 
  deter- 
  

   mination 
  of 
  antimony 
  in 
  its 
  highest 
  condition 
  of 
  oxidation 
  by 
  

   Weller,* 
  who 
  distils 
  the 
  iodine 
  from 
  the 
  solution, 
  collects 
  it 
  in 
  

   the 
  distillate 
  and, 
  determining 
  it 
  volumetrically, 
  calculates 
  from 
  

   the 
  amount 
  of 
  it 
  found 
  the 
  antimonic 
  salt 
  which 
  sets 
  it 
  free 
  

   according 
  to 
  the 
  equation 
  

  

  SbCl 
  5 
  + 
  2H-I= 
  SbCl 
  3 
  + 
  2HC1 
  + 
  II. 
  

  

  The 
  advantage 
  of 
  treating 
  the 
  residue, 
  rather 
  than 
  the 
  distil- 
  

   late, 
  in 
  analytical 
  processes 
  in 
  general 
  which 
  involve 
  distillation 
  

   is 
  so 
  obvious 
  as 
  to 
  constrain 
  us 
  to 
  seek 
  conditions 
  under 
  which 
  

   Bunsen's 
  reaction 
  may 
  be 
  applied 
  in 
  such 
  manner 
  that 
  the 
  

   antimony 
  shall 
  be 
  held 
  and 
  estimated 
  directly 
  in 
  the 
  residue. 
  

   The 
  general 
  plan 
  of 
  work 
  was 
  laid 
  down 
  in 
  a 
  similar 
  process 
  

   elaborated 
  in 
  this 
  laboratory 
  for 
  the 
  reduction 
  of 
  arsenic 
  acid.f 
  

   According 
  to 
  this 
  process 
  the 
  arsenic 
  to 
  be 
  reduced 
  is 
  taken 
  in 
  

   a 
  solution 
  of 
  appropriate 
  dilution, 
  and 
  treated 
  with 
  sulphuric 
  

   acid 
  in 
  adjusted 
  amount 
  and 
  an 
  excess 
  of 
  potassium 
  iodide. 
  

   The 
  liquid 
  thus 
  prepared 
  is 
  boiled 
  to 
  a 
  definite 
  degree 
  of 
  con- 
  

   centration, 
  the 
  iodine 
  then 
  remaining 
  unexpelled, 
  if 
  any, 
  is 
  

   bleached 
  by 
  the 
  very 
  careful 
  addition 
  of 
  dilute 
  (centinormal) 
  

   sulphurous 
  acid, 
  and 
  the 
  liquid 
  is 
  immediately 
  diluted 
  and 
  

   neutralized. 
  After 
  cooling, 
  the 
  reduced 
  arsenic 
  is 
  titrated 
  by 
  

   standard 
  iodine 
  in 
  presence 
  of 
  starch. 
  

  

  We 
  found 
  in 
  preliminary 
  experimentation 
  that 
  the 
  same 
  

   general 
  plan 
  of 
  treatment 
  is 
  available 
  in 
  the 
  handling 
  of 
  anti- 
  

   monic 
  compounds, 
  but 
  it 
  is 
  necessary 
  to 
  take 
  precautions 
  to 
  

   prevent 
  the 
  deposition 
  of 
  the 
  antimony 
  from 
  solution 
  upon 
  the 
  

   addition 
  of 
  the 
  sulphuric 
  acid. 
  Tartaric 
  acid 
  accomplishes 
  this 
  

   effect 
  satisfactorily 
  and 
  does 
  not, 
  as 
  the 
  result 
  proved, 
  intro- 
  

   duce 
  undesirable 
  complications. 
  It 
  transpired 
  also 
  that 
  the 
  

   dilution 
  of 
  the 
  solution 
  at 
  which 
  the 
  crystalline 
  iodide 
  or 
  oxy- 
  

   iodide 
  separates 
  out 
  during 
  the 
  boiling 
  is 
  greater 
  than 
  is 
  the 
  

   case 
  when 
  similar 
  amounts 
  of 
  arsenic 
  are 
  dealt 
  with. 
  It 
  

   appeared, 
  for 
  example, 
  that 
  concentration 
  to 
  45cm. 
  3 
  was 
  suffi- 
  

   cient 
  to 
  cause 
  crystallization 
  and 
  slight 
  sublimation 
  when 
  the 
  

  

  *Ann. 
  d. 
  Chem. 
  u. 
  Pharm., 
  ccxiii, 
  246. 
  

  

  f 
  Gooch 
  and 
  Browning, 
  this 
  Journal, 
  xl, 
  p. 
  66. 
  

  

  