﻿Gooch 
  and 
  Walker 
  — 
  Analysis 
  of 
  Iodides. 
  

  

  295 
  

  

  solution 
  of 
  hydrochloric 
  acid, 
  so 
  dilute 
  that 
  by 
  itself 
  it 
  is 
  with- 
  

   out 
  effect 
  on 
  iodic 
  acid, 
  acts 
  upon 
  a 
  mixture 
  of 
  iodic 
  acid 
  with 
  

   either 
  free 
  iodine 
  or 
  an 
  iodide 
  to 
  form 
  iodine 
  monochloride. 
  

   The 
  action 
  of 
  the 
  acid 
  carbonate 
  upon 
  the 
  iodine 
  chloride 
  or 
  

   bromide 
  may 
  produce 
  a 
  salt 
  of 
  the 
  oxy-acids 
  and 
  free 
  iodine. 
  

  

  The 
  practical 
  effects, 
  under 
  the 
  conditions 
  of 
  analysis, 
  of 
  the 
  

   reaction 
  between 
  iodine, 
  iodic 
  acid 
  and 
  the 
  halogen 
  acids 
  in 
  

   presence 
  of 
  sulphuric 
  acid, 
  and 
  of 
  reactions 
  which 
  may 
  occur 
  

   upon 
  neutralization 
  by 
  an 
  acid 
  carbonate, 
  were 
  studied 
  in 
  detail 
  

   in 
  a 
  number 
  of 
  experiments. 
  

  

  Table 
  I. 
  

  

  Effect 
  of 
  the 
  Carbonate. 
  

  

  

  [5 
  cm3 
  H 
  2 
  S0 
  

  

  i 
  (1 
  : 
  3). 
  Total 
  volume 
  of 
  liquid, 
  250 
  cm3 
  .] 
  

  

  I 
  (in 
  KI) 
  taken. 
  

  

  KHC0 
  3 
  in 
  excess. 
  

  

  I 
  found. 
  

  

  Error.- 
  

  

  

  grm. 
  

  

  cm 
  3 
  . 
  

  

  grm. 
  

  

  grm. 
  

  

  0) 
  

  

  0-0713 
  

  

  very 
  small 
  

  

  0*0707 
  

  

  0-0006 
  — 
  

  

  (2) 
  

  

  0'0715 
  

  

  very 
  small 
  

  

  0-0710 
  

  

  0-0005- 
  

  

  (3) 
  

  

  0-0713 
  

  

  10 
  

  

  0-0710 
  

  

  0-0003 
  — 
  

  

  (4) 
  

  

  0-0710 
  

  

  10 
  

  

  0-0706 
  

  

  0-0004 
  — 
  

  

  ( 
  5 
  ) 
  

  

  0-0723 
  

  

  10 
  

  

  0-0717 
  

  

  0-0006 
  — 
  

  

  (6) 
  

  

  0-0713 
  

  

  20 
  

  

  0-0709 
  

  

  0-0004 
  — 
  

  

  CO 
  

  

  0*0713 
  

  

  20 
  

  

  0-0709 
  

  

  0-0004 
  — 
  

  

  (8) 
  

  

  0-3565 
  

  

  very 
  small 
  

  

  0-3560 
  

  

  0-0005 
  — 
  

  

  (9) 
  

  

  0-3568 
  

  

  very 
  small 
  

  

  0-3561 
  

  

  0-0007 
  — 
  

  

  (10) 
  

  

  0-35 
  67 
  

  

  10 
  

  

  0-3563 
  

  

  0-0004 
  — 
  

  

  (11) 
  

  

  0-3596 
  

  

  10 
  

  

  0-3588 
  

  

  0-0008 
  — 
  

  

  (12) 
  

  

  0-3565 
  

  

  10 
  

  

  0-3665 
  

  

  o-oooo 
  

  

  (13) 
  

  

  03572 
  

  

  1 
  20 
  

  

  0-3560 
  

  

  0-0012 
  — 
  

  

  (14) 
  

  

  0-3567 
  

  

  20 
  

  

  0-3569 
  

  

  0-0002 
  + 
  

  

  The 
  preliminary 
  experiments 
  of 
  Table 
  I 
  were 
  made 
  to 
  bring 
  

   out 
  the 
  effect 
  of 
  neutralizing 
  with 
  the 
  acid 
  carbonate 
  and 
  sub- 
  

   sequently 
  titrating 
  with 
  an 
  alkaline 
  arsenite 
  a 
  solution 
  contain- 
  

   ing 
  sulphuric 
  acid 
  and 
  a 
  considerable 
  amount 
  of 
  free 
  iodine. 
  

   The 
  danger 
  of 
  mechanical 
  loss 
  of 
  iodine 
  during 
  the 
  efferves- 
  

   cence 
  accompanying 
  neutralization, 
  as 
  well 
  as 
  by 
  spontaneous 
  

   volatilization 
  from 
  the 
  surface 
  during 
  the 
  process 
  of 
  titration, 
  

   was 
  minimized 
  by 
  effecting 
  the 
  neutralization 
  in 
  the 
  trapped 
  

   Drexel 
  washing-bottle 
  to 
  be 
  described 
  later, 
  and 
  making 
  the 
  

   titration 
  in 
  the 
  same 
  tall 
  washing 
  cylinder 
  without 
  transfer. 
  

   To 
  varying 
  amounts 
  of 
  a 
  recently 
  standardized 
  decinormal 
  solu- 
  

   tion 
  of 
  iodine 
  were 
  added 
  successively 
  5 
  cm3 
  of 
  dilute 
  sulphuric 
  

   acid 
  and 
  varying 
  amounts 
  of 
  potassium 
  bicarbonate 
  in 
  excess 
  of 
  

   that 
  necessary 
  to 
  neutralize 
  the 
  free 
  acid, 
  decinormal 
  arsenious 
  

   acid 
  in 
  slight 
  excess 
  of 
  the 
  iodine, 
  5 
  cm3 
  of 
  starch 
  emulsion; 
  and 
  

   decinormal 
  iodine 
  to 
  coloration, 
  the 
  total 
  volume 
  of 
  the 
  liquid 
  

  

  