﻿Oxides 
  and 
  Sulphides 
  of 
  Iron, 
  etc. 
  

  

  61 
  

  

  Berthelot 
  derived 
  his 
  result 
  from 
  the 
  heat 
  of 
  solution 
  of 
  a 
  

   readily 
  soluble 
  magnetic 
  oxide 
  in 
  hydrochloric 
  acid. 
  LeChate- 
  

   lier 
  burned 
  in 
  oxygen 
  mixtures 
  of 
  ferrous 
  oxide 
  and 
  carbon 
  

   and 
  of 
  ferric 
  oxide 
  and 
  carbon, 
  and 
  based 
  his 
  calculations 
  on 
  

   B's 
  heat 
  of 
  formation 
  of 
  magnetic 
  oxide. 
  

  

  The 
  heat 
  effect 
  in 
  the 
  different 
  stages 
  of 
  oxidation 
  of 
  one 
  

   atom 
  of 
  oxygen 
  is 
  nearly 
  the 
  same, 
  as 
  LeChatelier 
  observed, 
  

   thus 
  : 
  

  

  Fe 
  + 
  O 
  = 
  64,300 
  c 
  

  

  2FeO 
  + 
  O 
  = 
  63,700 
  

  

  2Fe 
  + 
  30 
  = 
  3 
  X 
  64,100 
  

  

  3Fe 
  + 
  40 
  = 
  4 
  x 
  66,400 
  

  

  The 
  figure 
  for 
  the 
  last 
  is 
  higher 
  than 
  the 
  others 
  because 
  of 
  

   the 
  considerable 
  heat 
  of 
  combination 
  of 
  ferrous 
  with 
  ferric 
  

   oxide. 
  This 
  heat 
  effect 
  confirms 
  the 
  view 
  that 
  magnetite 
  is 
  

   meta-ferrous 
  ferrite. 
  

  

  After 
  the 
  foregoing 
  work 
  was 
  finished 
  the 
  paper 
  of 
  Ruff 
  and 
  

   Gersten,* 
  Ueber 
  das 
  Triferro-carbid, 
  came 
  to 
  the 
  writer's 
  

   notice. 
  In 
  the 
  investigation 
  they 
  obtained 
  for 
  the 
  heat 
  of 
  

   formation 
  of 
  Fe 
  3 
  4 
  267^,100 
  c 
  ± 
  200 
  c 
  and 
  FeO 
  60,400 
  ± 
  1800 
  c 
  . 
  

  

  Ferrous 
  Sulphide. 
  — 
  Allen, 
  Crenshaw 
  and 
  Johnstonf 
  state 
  

   that 
  by 
  heating 
  iron 
  in 
  hydrogen 
  sulphide 
  an 
  iron 
  sulphide 
  is 
  

   formed, 
  having 
  approximately 
  the 
  composition 
  of 
  FeS. 
  The 
  

   writer's 
  preparation, 
  prepared 
  by 
  this 
  process, 
  contained 
  1*7 
  per 
  

   cent 
  excess 
  of 
  sulphur, 
  equivalent 
  to 
  3*2 
  per 
  cent 
  of 
  FeS 
  2 
  . 
  

   The 
  following 
  are 
  the 
  results 
  : 
  

  

  Ferrous 
  sulphide 
  3*308 
  3*502 
  3*698 
  grams 
  

  

  Sodium 
  peroxide 
  ... 
  20* 
  20* 
  20* 
  

  

  Water 
  equiv. 
  of 
  system 
  3110 
  3171 
  3170 
  

  

  Temperature 
  interval 
  2*994 
  3*141 
  3*307° 
  

  

  Heat 
  effect.. 
  9311 
  9960 
  10483 
  c 
  

  

  " 
  " 
  of 
  iron 
  50 
  50 
  50 
  

  

  " 
  " 
  " 
  FeS 
  9261 
  9910 
  10433 
  

  

  " 
  " 
  " 
  1 
  gram 
  FeS 
  2800 
  2830 
  2822 
  

  

  The 
  mean 
  is 
  2817 
  c 
  . 
  Allowing 
  for 
  0*032 
  gram 
  of 
  FeS 
  2 
  with 
  a 
  

   heat 
  effect 
  of 
  106 
  c 
  we 
  have 
  2801 
  c 
  for 
  1 
  gram 
  of 
  ferrous 
  

   sulphide, 
  and 
  for 
  1 
  gram 
  molecule 
  246,200 
  c 
  . 
  The 
  heat 
  of 
  

   formation 
  is 
  derived 
  as 
  follows 
  : 
  

  

  S 
  + 
  3Na 
  2 
  2 
  = 
  169,000 
  c 
  

  

  Fe 
  + 
  l^Na 
  9 
  9 
  = 
  96,000 
  

  

  Fe 
  + 
  S 
  + 
  4|Na 
  2 
  2 
  = 
  265,000 
  

  

  FeS 
  + 
  4|Na 
  2 
  2 
  = 
  246,200 
  

  

  Fe 
  + 
  S 
  (rhombic) 
  = 
  FeS 
  (amor.) 
  = 
  18,800 
  

  

  *Ber. 
  d. 
  Chem. 
  Ges., 
  xlvi, 
  394. 
  fZeit. 
  f. 
  Anorgan. 
  Chem., 
  Ixxvi, 
  224. 
  

  

  