﻿56 
  

  

  Mixter 
  — 
  Heat 
  of 
  Formation 
  of 
  the 
  

  

  1 
  

  

  Iron 
  .... 
  2-550 
  

  

  Sulphur 
  1-500 
  

  

  Sodium 
  peroxide 
  20- 
  

  

  Water 
  equivalent 
  of 
  

  

  system 
  ._; 
  3080 
  

  

  Temperature 
  interval 
  4*016 
  

  

  Heat 
  effect 
  12369 
  

  

  Heat 
  effect 
  of 
  sulphur 
  —7905 
  

  

  " 
  " 
  " 
  ignition 
  

  

  wire 
  — 
  80 
  

  

  4384 
  

   Heat 
  effect 
  of 
  1 
  grm. 
  

  

  Fe 
  1719 
  

  

  2 
  

  

  3 
  

  

  4 
  

  

  1-754 
  

   1-500 
  

   19- 
  

  

  1-754 
  

   1-500 
  

   20- 
  

  

  3-000 
  grms' 
  

   1-500 
  

  

  22- 
  

  

  3078 
  

   3-573 
  

  

  3188 
  

   3-423 
  

  

  4108 
  

   3-180° 
  

  

  10998 
  

   — 
  7905 
  

  

  10912 
  

   — 
  7905 
  

  

  13063 
  c 
  

  

  — 
  7860 
  

  

  — 
  80 
  

  

  — 
  60 
  

  

  — 
  45 
  

  

  3013 
  

  

  2947 
  

  

  5158 
  

  

  1718 
  

  

  1680 
  

  

  1719 
  

  

  Ferric 
  Oxide. 
  — 
  Ferric 
  oxide 
  was 
  made 
  by 
  heating 
  the 
  

   hydroxide 
  to 
  a 
  faint 
  red. 
  When 
  cold 
  it 
  was 
  pulverized 
  and 
  

   sifted. 
  Each 
  portion 
  used 
  was 
  heated 
  again 
  to 
  a 
  dull 
  red 
  

   before 
  weighing 
  to 
  drive 
  off 
  hydroscopic 
  water. 
  Further 
  

   heating 
  was 
  found 
  not 
  to 
  change 
  the 
  weight. 
  All 
  heating 
  was 
  

   in 
  an 
  electric 
  furnace 
  where 
  there 
  was 
  no 
  liability 
  of 
  reduc- 
  

   tion. 
  The 
  following 
  table 
  contains 
  all 
  of 
  the 
  calorimetric 
  

   results 
  with 
  ferric 
  oxide. 
  

  

  The 
  fusions 
  of 
  1 
  and 
  2 
  were 
  dark 
  colored 
  and 
  gave 
  with 
  

   cold 
  water 
  ferric 
  hydroxide 
  and 
  red 
  solutions 
  containing 
  sodium 
  

   ferrate. 
  From 
  the 
  water 
  solution 
  of 
  2 
  barium 
  ferrate 
  precip- 
  

   itated 
  on 
  adding 
  barium 
  chloride. 
  The 
  fusions 
  3 
  and 
  4 
  were 
  

   black 
  on 
  top 
  but 
  white 
  below, 
  and 
  the 
  remaining 
  were 
  white 
  

   throughout. 
  The 
  water 
  solutions 
  of 
  all 
  except 
  the 
  first 
  two 
  

   were 
  white 
  and 
  free 
  from 
  iron, 
  proof 
  that 
  ferrate 
  was 
  not 
  

   formed. 
  In 
  1 
  and 
  2, 
  where 
  the 
  temperature 
  due 
  to 
  the 
  reac- 
  

   tions 
  was 
  lower 
  than 
  in 
  the 
  others, 
  both 
  ferrate 
  and 
  ferrite 
  

   were 
  formed, 
  and 
  hence 
  the 
  results 
  are 
  without 
  value. 
  Of 
  the 
  

   remaining 
  experiments 
  the 
  last 
  three 
  are 
  to 
  be 
  regarded 
  as 
  

   better 
  than 
  3 
  and 
  4, 
  since 
  larger 
  amounts 
  of 
  ferric 
  oxide 
  and 
  

   smaller 
  quantities 
  of 
  sulphur 
  were 
  taken. 
  The 
  average 
  of 
  5, 
  6 
  

   and 
  7 
  is 
  363 
  c 
  . 
  For 
  1 
  gram 
  molecule 
  of 
  ferric 
  oxide 
  combining 
  

   with 
  sodium 
  oxide 
  the 
  result 
  is 
  58000°. 
  

  

  Van 
  Bemmelen 
  and 
  Klobbie* 
  prepared 
  sodium 
  ferrite, 
  

   Na 
  2 
  Fe 
  2 
  4 
  , 
  by 
  heating 
  a 
  mixture 
  of 
  ferric 
  oxide 
  and 
  sodium 
  

   hydroxide. 
  They 
  found 
  it 
  to 
  be 
  slowly 
  decomposed 
  by 
  water. 
  

   Hilpert 
  and 
  Kohlmeyerf 
  consider 
  that 
  calcium 
  orthoferrite, 
  

   3CaO.Fe 
  2 
  3 
  , 
  is 
  formed 
  at 
  1410°. 
  It 
  is 
  not 
  possible 
  to 
  

   decide 
  whether 
  orthosodium 
  ferrite, 
  Na 
  3 
  Fe0 
  3 
  , 
  or 
  meta 
  ferrite, 
  

  

  * 
  J. 
  Prac. 
  Ch.. 
  xlvi, 
  497, 
  1892. 
  

  

  fBer 
  d. 
  deutsch. 
  Cheixi. 
  Gesell., 
  xlii, 
  4581, 
  1909. 
  

  

  