﻿402 
  

  

  Peters 
  — 
  Separation 
  and 
  Determination 
  

  

  mercury 
  in 
  form 
  of 
  mercurous 
  nitrate, 
  gave 
  plus 
  errors 
  of 
  

   0*0011 
  gms., 
  0*0017 
  gms. 
  and 
  0*0028 
  gms. 
  respectively, 
  or 
  1*5 
  per 
  

   cent. 
  The 
  precipitate 
  when 
  dissolved 
  in 
  sulphuric 
  acid 
  and 
  

   titrated 
  gave 
  no 
  better 
  results. 
  To 
  obviate 
  this 
  difficulty 
  the 
  

   ammonium 
  oxalate 
  solutiou 
  was 
  matched 
  on 
  the 
  permanganate 
  

   and 
  the 
  oxalic 
  acid 
  in 
  the 
  filtrate 
  determined. 
  The 
  results 
  

   obtained 
  by 
  this 
  method, 
  given 
  in 
  the 
  

   quite 
  accurate. 
  

  

  following 
  

  

  table, 
  

  

  are 
  

  

  7 
  

  

  8 
  

  

  9 
  

  

  10 
  

  

  Hg 
  

  

  taken 
  as 
  

  

  Hg 
  2 
  (N0 
  3 
  ) 
  5 
  

  

  gms. 
  

  

  0*1825 
  

   0*1217 
  

   0*1217 
  

   0-1217 
  

   0-3042 
  

  

  0-1217 
  

   0-1217 
  

   0-1825 
  

   0-3042 
  

   0-1217 
  

  

  Excess 
  

   of 
  ammonium 
  

   oxalate 
  

  

  Hg 
  

  

  found. 
  

  

  gms. 
  

  

  0-1823 
  

   0-1218 
  

   0-1206 
  

   0-1210 
  

   0-3034 
  

  

  0-1220 
  

   0-1211 
  

   0-1827 
  

   0-3040 
  

   0-1202 
  

  

  app. 
  

  

  10 
  

  

  cirr 
  

  

  0-90 
  

   0-93 
  

   0-99 
  

   4-05 
  

  

  4-97 
  

  

  0-93 
  

   0-97 
  

   0-89 
  

   0-82 
  

   4-10 
  

  

  HC1 
  

   Sp.gr. 
  

  

  1-16 
  

  

  cm 
  3 
  

   A 
  

  

  5- 
  

  

  5 
  

  

  5' 
  

  

  5' 
  

  

  5 
  

   B 
  

  

  MnCl 
  2 
  .4H 
  2 
  

   gms. 
  

  

  "5 
  

  

  •5 
  

   •5 
  

   •5 
  

   •5 
  

  

  H 
  2 
  S0 
  4 
  

   1:1 
  

  

  cm 
  3 
  

  

  Error 
  

   as 
  Hg 
  

  

  — 
  0*0002- 
  

   + 
  00001 
  

   —0-0011 
  

  

  — 
  0-0007 
  

  

  — 
  0-0008 
  

  

  + 
  0-0003 
  

  

  — 
  0-0006 
  

   + 
  0-0002 
  

   -0-0002 
  

  

  — 
  0*0015- 
  

  

  In 
  the 
  experiments 
  recorded 
  in 
  section 
  A 
  of 
  the 
  table 
  the 
  

   filtrate 
  was 
  titrated 
  in 
  the 
  presence 
  of 
  hydrochloric 
  acid 
  and 
  a 
  

   manganous 
  salt, 
  at 
  a 
  temperature 
  of 
  20°-40°.* 
  In 
  the 
  experi- 
  

   ments 
  under 
  section 
  B 
  sulphuric 
  acid 
  was 
  added 
  and 
  the 
  solution 
  

   heated 
  in 
  the 
  usual 
  manner. 
  An 
  excess 
  of 
  ammonium 
  oxalate 
  as 
  

   shown 
  in 
  exps. 
  4, 
  5 
  and 
  10, 
  interferes 
  in 
  no 
  way. 
  

  

  The 
  separation 
  of 
  mercurous 
  salt 
  from 
  small 
  quantities 
  of 
  

   mercuric 
  salts, 
  by 
  the 
  means 
  of 
  dilute 
  nitric 
  acid, 
  sp. 
  gr. 
  l*15 
  y 
  

   was 
  next 
  attempted. 
  It 
  is 
  statedf 
  that 
  mercurous 
  oxalate 
  is 
  

   insoluble 
  in 
  cold 
  dilute 
  nitric 
  acid, 
  while 
  mercuric 
  oxalate 
  is 
  

   more 
  or 
  less 
  soluble 
  in 
  the 
  same 
  reagent. 
  Before 
  attempting 
  

   any 
  separation, 
  however, 
  there 
  are 
  three 
  factors 
  with 
  reference 
  to 
  

   the 
  action 
  of 
  the 
  nitric 
  acid 
  which 
  need 
  to 
  be 
  determined 
  — 
  first, 
  

   the 
  maximum 
  amount 
  of 
  nitric 
  acid 
  that 
  may 
  be 
  present 
  in 
  

   titration 
  of 
  an 
  oxalate 
  without 
  interference 
  ; 
  second, 
  the 
  maxi- 
  

   mum 
  amount 
  of 
  nitric 
  acid 
  that 
  may 
  be 
  present 
  in 
  a 
  precipi- 
  

   tation 
  of 
  mercurous 
  oxalate 
  without 
  having 
  any 
  perceptible 
  

   solvent 
  action 
  upon 
  the 
  same 
  ; 
  and, 
  third, 
  the 
  amount 
  of 
  

   mercuric 
  oxalate 
  which 
  will 
  be 
  held 
  in 
  solution 
  by 
  given 
  

   amounts 
  of 
  nitric 
  acid. 
  

  

  * 
  G-ooch 
  aD(l 
  Peters, 
  this 
  Journal, 
  vii, 
  461, 
  1899. 
  

   f 
  Souchay 
  and 
  Lenssen, 
  Ann. 
  d. 
  Chem., 
  cii, 
  43. 
  

  

  