﻿Dialkylphosphoric 
  and 
  Benzenedisulphonic 
  Acids. 
  65 
  

  

  acids 
  (C 
  6 
  H 
  2 
  NH 
  2 
  CH 
  3 
  (S0 
  3 
  H) 
  2 
  ) 
  in 
  order 
  to 
  ascertain 
  the 
  effect 
  of 
  

   the 
  different 
  positions 
  of 
  the 
  methyl 
  group 
  on 
  the 
  dissociation 
  

   of 
  the 
  acids. 
  Armstrong 
  and 
  Worley* 
  studied 
  a 
  number 
  of 
  

   sulphonic 
  derivatives 
  but 
  their 
  work 
  on 
  the 
  simple 
  benzenedi- 
  

   sulphonic 
  acids 
  was 
  coniined 
  to 
  the 
  use 
  of 
  the 
  three 
  isomeric 
  

   acids 
  as 
  catalytic 
  agents 
  in 
  the 
  hydrolysis 
  of 
  cane 
  sugar 
  in 
  order 
  

   to 
  determine 
  their 
  relative 
  strengths. 
  They 
  found 
  the 
  meta- 
  

   acid 
  slightly 
  stronger 
  than 
  the 
  para-acid 
  and 
  both 
  very 
  much 
  

   stronger 
  than 
  the 
  ortho-acid. 
  Our 
  results 
  obtained 
  both 
  by 
  the 
  

   conductivity 
  method 
  and 
  the 
  hydrolysis 
  method 
  are 
  only 
  

   partially 
  in 
  agreement 
  with 
  the 
  results 
  of 
  Armstrong 
  and 
  

   Worley. 
  Both 
  methods 
  of 
  measurement 
  gave 
  concordant 
  

   results 
  and 
  show 
  the 
  para-acid 
  to 
  be 
  a 
  little 
  stronger 
  than 
  the 
  

   meta-acid 
  and 
  both 
  very 
  much 
  stronger 
  than 
  the 
  ortho-acid. 
  

   Our 
  results 
  are 
  really 
  in 
  better 
  agreement 
  with 
  Armstrong 
  and 
  

   Worley's 
  structure 
  theory 
  for 
  the 
  explanation 
  of 
  the 
  catalytic 
  

   action 
  of 
  the 
  three 
  isomeric 
  benzenedisulphonic 
  acids 
  than 
  

   their 
  results, 
  although 
  these 
  acids, 
  as 
  shown 
  by 
  our 
  conductiv- 
  

   ity 
  measurements, 
  require 
  no 
  special 
  structure 
  theory 
  to 
  

   explain 
  their 
  catalytic 
  activity. 
  The 
  general 
  ionization 
  theory 
  

   amply 
  covers 
  the 
  case 
  of 
  the 
  three 
  isomeric 
  benzenedisulphonic 
  

   acids. 
  The 
  results 
  of 
  our 
  conductivity 
  measurements 
  are 
  

   given 
  in 
  Table 
  II. 
  

  

  Table 
  II 
  

  

  Conductivities 
  and 
  degrees 
  of 
  dissociation 
  of 
  the 
  isomeric 
  benzenedisul- 
  

   phonic 
  acids. 
  25°. 
  

  

  Dilu- 
  

  

  

  Ortho-acid 
  

  

  

  Meta-acid 
  

  

  Para-acid 
  

  

  tion 
  

  

  

  per 
  cent 
  

  

  

  per 
  cent 
  

  

  

  per 
  cent 
  

  

  V 
  

  

  fJiV 
  

  

  dissociated 
  

  

  fiv 
  

  

  dissociated 
  

  

  [MV 
  

  

  dissociated 
  

  

  8 
  

  

  317*2 
  

  

  83-09 
  

  

  339-2 
  

  

  88-64 
  

  

  343-3 
  

  

  89-47 
  

  

  16 
  

  

  329-4 
  

  

  86-28 
  

  

  351-5 
  

  

  91-63 
  

  

  353-8 
  

  

  92-21 
  

  

  32 
  

  

  341-3 
  

  

  89-39 
  

  

  359-3 
  

  

  93-66 
  

  

  361-6 
  

  

  94-24 
  

  

  64 
  

  

  351-9 
  

  

  92-17 
  

  

  367-3 
  

  

  95-75 
  

  

  370-5 
  

  

  96-56 
  

  

  128 
  

  

  361-1 
  

  

  94-59 
  

  

  374-2 
  

  

  97-52 
  

  

  375-2 
  

  

  97-78 
  

  

  256 
  

  

  367-5 
  

  

  96-79 
  

  

  380-1 
  

  

  99-09 
  

  

  3801 
  

  

  99-06 
  

  

  512 
  

  

  374-7 
  

  

  98-06 
  

  

  383-6 
  

  

  100- 
  

  

  383-1 
  

  

  99-84 
  

  

  1024 
  

  

  377-5 
  

   381-7 
  

  

  98-90 
  

   100- 
  

  

  

  

  383-7 
  

  

  100- 
  

  

  2048 
  

  

  

  

  

  2048 
  

  

  381-6 
  

  

  100- 
  I 
  

  

  5y 
  single 
  dilution. 
  

  

  

  

  (c) 
  Catalytic 
  action 
  of 
  the 
  isomeric 
  oenzenedisulphonic 
  

   acids 
  in 
  the 
  hydrolysis 
  of 
  ethyl 
  acetate. 
  — 
  The 
  ionization 
  of 
  

   these 
  acids 
  as 
  determined 
  by 
  the 
  conductivity 
  method 
  was 
  con- 
  

   firmed 
  by 
  using 
  them 
  in 
  decinormal 
  concentration 
  in 
  the 
  

   hydrolysis 
  of 
  ethyl 
  acetate 
  at 
  25°. 
  In 
  order 
  to 
  determine 
  pos- 
  

   itively 
  the 
  relative 
  strength 
  of 
  the 
  meta- 
  and 
  para-acids 
  dupli- 
  

  

  * 
  Armstrong 
  and 
  Worley, 
  1. 
  c. 
  

  

  Am. 
  Jour. 
  Sci. 
  — 
  Fourth 
  Series, 
  Vol. 
  XLIII, 
  No. 
  253.— 
  January, 
  1917. 
  

   5 
  

  

  