Table Of Contentइंटरनेट मानक
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“The Right to Information, The Right to Live” “Step Out From the Old to the New”
IS 5316 (1998): Ammonium carbonate [CHD 1: Inorganic
Chemicals]
“!ान $ एक न’ भारत का +नम-ण”
Satyanarayan Gangaram Pitroda
““IInnvveenntt  aa  NNeeww  IInnddiiaa  UUssiinngg  KKnnoowwlleeddggee””
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता हहहहै””ै”
Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
IS 5316:  1998 
 
(~J!i!~) 
Indian  Standard 
AMMONIUM  CARBONATE  - 
SPECIFICATION 
( First  Revision  ) 
ICS  661:523 
 
 
 
 
0  BIS  1998 
BUREAU  OF  INDIAN  STANDARDS 
MANAK  BHAVAN,  9  BAHADUR  SHAH  ZAFAR  MARG 
NEW  DELHI  110002 
 
May  1998  Price Group  7
,sdicA  seilaklA  dna  sedilaH  lanoitceS  ,eettimmoC CHD  2 
 DROWEROF
 sihT  naidnI  dradnatS  tsriF(  )noisiveR was  adopted   yb the   uaeruB of   naidnI  ,sdradnatS after  the  draft   dezilanif
 yb the   ,sdicA  seilaklA  dna  sedilaH  lanoitceS  eettimmoC had   neeb  devorppa  yb the   lacimehC  noisiviD  .licnuoC
 muinommA  etanobrac  sdnif  evisnetxe  esu  ni  gnikab powders,   erif  srehsiugnitxe  dna  gnillems  ;stlas for   gnihsaw
 dna  gnittafed  ,snelloow  ,gninnat  dna  gnitarapes cacao   stneutitsnoc as   tnadrom  ni  ;gnieyd  ni the   erutcafunam of 
 rebbur  ,selcitra  niesac  eulg  dna  niesac  ;sruoloc  dna as  a   tnegaer  ni  lacitylana  .yrtsimehc
 ehT  erup  muinomma  etanobrac (NH&  CO3   si  demrof  no  gnitaert the   laicremmoc  muinomma  etanobrac  htiw
 ainomma  dna  .sezillatsyrc  tI  si  yrev  elbulos  ni water   dna  esopmoced  otni  ,ainomma  nobrac  edixoid  dna water 
 no  .gnitaeh  tI  sesopmoced  ni  tsiom  ria  ot  muinomma  etanobracib  .)30CitHN(
 sihT  dradnats was   yllanigro  dehsilbup  ni 1969.   nI  siht  noisiver  cirtemirolac  dohtem for   noitanimreted of 
 ,sedirolhc  yvaeh  ,slatem phosphate,   setacilis  dna  cirtemidibruT  dohtem for   noitanimreted of   ruhplus  evah  neeb
 detaroprocni as   na  etanretla  .dohtem  sihT  noisiver  osla  setaroprocni  tnemdnemA No.  1   deussi  ni 198  1. 
 ehT  noitisopmoc of  the   eettimmoc  elbisnopser for  the   noitalumrof of   siht  dradnats  si  nevig  ni  xennA  .C
 roF the   esoprup of   gnidiced whether  a   ralucitrap  tnemeriuqer of   siht  dradnats  si  deilpmoc  ,htiw the   lanif  ,eulav
 devresbo or   ,detaluclac  gnisserpxe the   tluser of  a  test  or   ,sisylana  llahs  eb  dednuor off   ni  ecnadrocca  htiw  SI 2   :
1960   seluR‘ for   gnidnuor off   laciremun  seulav (revised)‘.  The  rebmun of   tnacifingis  secalp  deniater  ni the 
 dednuor off   eulav  dluohs  eb the   emas as  that  of  the   deificeps  eulav  ni  siht  .dradnats
IS 5316  : 1998 
Indian Standard 
AMMONIUM CARBONATE  - 
SPECIFICATION 
( First Revision ) 
1 SCOPE   )a  edarG 1   -  lacitylana  ,tnegaer and 
 )b  edarG 2   -  .lacinhcet
1.1 This  standard   sebircserp  eht  stnemeriuqer and   eht
 sdohtem  fo sampling  and   tset  rof  muinomma 4  REQUIREMENTS 
 ,etanobrac  lacitylana  tnegaer and   .lacinhcet
4.1  Description 
2  REFERENCES 
 ehT  lairetam shall   eb  ni  eht  mrof  fo  ,drah  etihw
2.1  ehT  naidnI Standards   detsil  woleb  niatnoc  tneculsnart  enillatsyrc masses   ro  sebuc  ro  .redwop  tI
 snoisivorp  hcihw  hguorht  ecnerefer  ni this   ,txet shall   evah  gnorts odour   fo ammonia,  sharp   etsat and 
 etutitsnoc  snoisivorp  fo this   naidnI  .dradnatS At   eht  enilakla  .noitcaer
 emit  fo  ,noitacilbup  eht  snoitide  detacidni  erew  .dilav
4.2   ehT  lairetam shall   osla  mrofnoc  ot  eht
 llA standards   era  tcejbus  ot  ,noisiver and   seitrap  ot
 stnemeriuqer  deificeps  ni  elbaT  1  nehw  detset  ni
 stnemeerga  desab  no this  standard   era  degaruocne  ot
 ecnadrocca  htiw  eht  sdohtem  debircserp  ni  xennA A. 
 etagitsevni  eht  ytilibissop  fo  gniylppa  eht  tsom  tnecer
 snoitide  fo  eht standards   detacidni  :woleb 5  PACKING AND MARKING 
IS No.  Title 
5.1  Packing 
264  : 1976   cirtiN  dica  dnoces( revision) 
 edarG 1   lairetam shall   eb  dekcap  ni  ,selttob and   edarG
265   : 1993   cirolhcordyH  dica yburth revision) 
2   lairetam shall   eb  dekcap  ni  denil-citsalp drums.   ehT
 :0701 1992   retaW  tnegaer  edarg  driht( revision)   sreniatnoc shall   eb  ylthgit  desolc  htiw  thgitria lids. 
2088   : 1983   sdohteM  noitanimretedfo  fo  cinesra 5.2  Marking 
 dnoces( revision) 
   ehT  sreniatnoc shall   eb  dekram  htiw  eht  gniwollof
3  GRADES   
   :noitamrofni
 
3.1   ehT  lairetam shall   evah  owt  ,sedarg  :yleman  )a  emaN and   edarg  fo  eht  ;lairetam
Table 1 Requirements for Ammonium Carbonate 
 )4.1.01-Adna4.1.9-A,4.1.8-A,5.1.7-A,4.1.6-A,4.1.5-A,1.2.5,2.4sesua1C(
 tS  ,tseT
No.  Characteristic  Requirement  Method of 
A 
Ref to Cl No. in 
f  1 
Annex A 
Grade  I Grade 2 
(I)  (2)  (3)  (4)  (5) 
i)  Assay (as NHs), percent by mass,M  in  31  30  A-2 
ii)  Insoluble matter, percent by mass,M  ax  0.005  0.005  A-3 
iii)  Non-volatile matter, percent by mass,M  ax  0.01  0.02  A-4 
iv)  Chlorides (as Cl). percent by mass,M  ar  0.0002  0.002  A-S 
v)  Sulphur compounds( as SO.& percent by mass,M  ar  0.002  0.005  A-6 
vi)  Phosphates (as PO&  percent by mass,M  ax  0.001  -  A-l 
vii)  Silicates (as SiOz), percent by mass,M  ur  o.OaI 5  -  A-8 
viii)  Heavy metals (as Pb). percent by mass,M  ax  o.GOO2   0.000 5  A-9 
ix)  Iron (as Fe), percent by mass,M  UX  0.000  1  ooo.o 5  A-IO 
 I
x)  Arsenic content (as AszOs) ppm. Max  2  2  A-l 
1
IS 5316:  1998 
b)  Name  of the manufacturer  and his recognized  522.1  The use of the Standard  Mark  is governed by 
trade-mark,  if any;  the provisions of the Bureau of Indian Standards  Act, 
c)  Mass   ’fo the material.  batch number and date of  1986 and the Rules and Regulations  made thereunder. 
packing;  and  The details of conditions,  under which the licence for 
d)  The words   PEEK‘  YLTHGIT  DESOLC  NI A  the  use  of  Standard  Mark’may  be  granted  to 
 LOOC  .’ECALP manufacturers or producers may be obtained  morf  eht
 naidnI Standards. 
Bureau of 
5.2.1   lluF
analytical  data for the characteristics given  6 
SAMPLING 
in Table  I  shall  also  be given  on the label of the 
containers of Grade  I material.  6.1  Representative  samples of the material  shall be 
drawn and judged  for conformity  to the requirements 
5.2.2  The  containers  may  also be marked  with  the 
of this specification  in accordance with the procedure 
Standard Mark. 
prescribed in Annex  B. 
ANNEX  A 
(Clause 4.2, and  Tuble   )1
ANALYSIS  OF AMMONIUM  CARBONATE 
A-l  QUALITY  OF REAGENTS  where 
v  =  volume  in  ml  of  sodium  hydroxide 
A-l.1  Unless specified otherwise, pure chemicals and 
consumed by excess of acid, 
distilled  water (see IS  1070) shall be used in tests.  N2  =  normality  of  sodium  hydroxide 
NOTE  -  ‘Pure chcmicals’shnll  mean chemicals  that do not  solution, 
cohlam Impurities which affect the results of analysis.  NI  =  normality  of hydrochloric  acid, and 
 2-A M  =  mass in grams of the material  taken for 
DETERMINATION  OF AMMONIUM 
the test. 
CARBONATE 
A-3  DETERMINATION  OF INSOLUBLE 
A-2.1  Apparatus 
MATTER 
A-2.1.1  Gluss-Stoppered  Weighing Bottle  A-3.1  Procedure 
A-2.2  Reagents  Dissolve  50 g of the sample in 100 ml of water, heat 
to  boiling  and  digest  in  a covered  beaker  on  a 
A-2.2.1  Stundard  Hydrochloric  Acid -  I N.  steam-bath for I hour.  Filter through a tared filtering 
 
  crucible,  wash thoroughly  and dry at IO5 f  2°C. 
A-2.2.2  Standurd Sodium Hydroxide  Solution -  I N. 
 
A-3.2  Calculation 
A-2.2.3  Methyl  Orange  Indicator  Solution -  Dis- 
solve 0. I g of methyl orange in I 000 ml of water and  Insoluble matter, 
100 MI 
filter.  percent by mass = -- 
M2 
A-2.3  Procedure 
where 
Accurately  weigh  a glass-stoppered  weighing  bottle  MI  =  mass in grams of the residue, and 
containing  IO ml of water.  Add  2.0  to 2.5 g of the  M2  =  mass in grams of the material  taken for 
sample  and  reweigh.  Measure  50  ml  of  1 N  the test. 
hydrochloric  acid in a beaker, put the weighing  bottle 
A-4  DETERMINATION  OF  NON-VOLATILE 
with the sample in it, open the stopper and wash with 
MATTER 
water.  Add  sufficient  water  to completely  cover the 
weighing  bottle and titrate the excess of acid with  I N  A-4.1  Procedure 
sodium hydroxide  using methyl orange indicator. 
Accurately  weigh  about  100 g of the sample  into  a 
A-2.4  Calculation  tared  dish,  add  IO  ml  of  water,  volatilize  on  a 
steam-bath and dry for I hour at I05 f  2°C. 
Assay (as NH,), 
 I .703 (50 NI -  v N2)  A-4.1.1   evreseR  eht residue obtained after drying for 
percent by mass = 
M  the test for heavy metals. 
 
2
SI 5316  : 1998 
 etanaycoiht  ,xelpmoc  eht  ytisnetni  fo  hcihw is 
A-4.2  Calculation 
 lanoitroporp  ot  eht  edirolhc  .tnetnsc  ehT  ecnabrosba
 elitalov-noN  ,rettam
 fo this   ruoloc is   derusaem at  450   mn  .htgnelevaw
IOOMI 
 tnecrep  yb mass  =   -
M2   2.2.5-A
Apparatus 
 erehw
 ni grams   fo  eht  ,eudiser and  A-5.2.2.1  Standard laboratory apparatus 
MI  =  mass 
M2  =  mass   ni grams   fo  eht  lairetam  nekat  rof
A-5.2.2.2  Spectrophotometer or photocoforimeter 
 eht  .tset
 lm  .yticapac
 5-A  TSET FOR   SEDIROLHC A-5.2.2.3  Platinum evaporating dish, 60 
 3.2.5-A
 owT  sdohtem  era  .debircserp  dohteM A  shall   eb Reagents 
 eerefer  dohtem  ni  esac  fo  ,etupsid and   dohteM  B  eht
A-5.2.3.1  Ferric  ammonium sulphate solution, 0.25 
 evitanretla  .dohtem
molll. 
A-5.1  Method  A (Turbidimetric  Method)   evlossiD 49.02  g   fo  cirreF  muinommA  etahplus
 etardyhacedod  ]OzH2l.&OS(&HN(eF[  ni 200   lm  fo
A-5.1.1  Apparatus 
 etulid  cirtin  dica  tuoba( 1.5   )l/lm-n and   etulid  ot 500   lm
 lm  .yticapac
A-5.1.1.1  Nessler cylinders  -  50   htiw  dellitsid  .retaw
 2.1.5-A
Reagents   2.3.2.5-A
Mercury (II) thiocyanate solution 
A-5.1.2.1  Sodium carbonate 
 detarutaS  noitulos  ni  etulosba  lyhte  .lohocla
 SI 264. 
A-5.1.2.2  Concentrated  nitric acid -  see 
 3.3.2.5-A
Standard chloride solution 
 3.2.1.5-A  yletamixorppa
Silver  nitrate  solution - 
4   tnecrep  .)v/w(  hgieW  yletarucca 0.165  0  g   fo  ylsuoiverp  deird  ta(
500°C)  and   delooc  muidos  edirolhc  lacitylana(  ,)edarg
 4;2.1.5-A
Standard chloride solution   sevlossid  ni a   rekaeb  ni  dellitsid  retaw and 
 evlossiD 1.648  g   fo  muidos  ,edirolhc  deird at  105   f  ylevitatitnauq  refsnart  otni a   eno  ertil  cirtemulov  ,ksalf
2’C,   ni  retaw and   etulid  ot 1  000   .lm  etuliD 10   lm  fo  etulid  ot  kram and   xim  .llew 1   lm  fo this   noitulos =  100 
this   noitulos  ot 1  000   .lm  enO  ertilillim  fo  eht  detulid  gt.f  fo Cl. 
 noitulos  sniatnoc 0.01   gm  fo  edirolhc (as   .)lC
 4.3.2.5-A
Dilute standard chloride solution 
 3.1.5-A
Procedure 
 refsnarT 50   lm  fo standard   edirolhc  noitulos
 evlossiD 2  g   fo  eht  elpmas  ni 25   lm  fo  toh  ,retaw add   )3.3.2.5-A(  otni a   lm-005  cirtemulov  ,ksalf  etulid  htiw
 tuoba 10   gm  fo  muidos  etanobrac and   etaropave  ot  dellitsid  retaw  ot  eht  kram and   xim  .llew 1   lm  fo this 
 ssenyrd  no a   .htabmaets  evlossiD    eht  eudiser  ni 20   lm  noitulos =  10  pg   fo Cl. 
 fo  ,retaw  retlif  ni a   relsseN  ,rednilyc    and  add  1   lm  fo
 cirtin  dica and  1   lm  fo  revlis  etartin  .noitulos  etuliD  ot  5.3.2.5-A Sulphuric  acid solution,  yletamixorppa 1 
50   lm and   .xim  yrraC  tuo a   lortnoc  tset using  0.4   ,lm moln. 
 ni  esac  fo  edarG 1   ,lairetam  ro 4.0   lm  ni  esac  fo  ruoP 56   lm  fo  detartnecnoc  ciruhplus  dica  otni 944   lm
 edarG 2   ,lairetam  fo standard   edirolhc  noitulos  ni  ecalp
 fo  dellitsid  retaw  ,ylwols  xim and   .looc
 fo  eht  elpmas  eht’dna  emas  seititnauq  fo  rehto  stnegaer
 ni  eht  emas  latot  emulov  fo  eht  noitcaer  .erutxim  4.2.5-A Procedure 
 4.1.5-A  ehT  timil  debircserp  ni  elbaT 1   rof  edarG 1  A-5.2.4.1  Calibration 
and   edarG 2  shall   eb  nekat as   ton  gnivah  neeb  -xe
 seires  fo  xis  lm-05  cirtemulov  ,sksalf  refsnart
 fi  eht  ytidibrut  decudorp  ni  eht  tset  htiw  eht Into a 
ceeded 
standard   edirolhc  noitulos  )4.3.2.5-A( as   nevig  :woleb
 lairetam is   ton  retaerg than   decudorp  ni  eht  lortnoc
 .stset
Standard Chloride  Corresponding Mass of 
 2.5-A Solution,  lm Chloride (as Cl),  kg 
Method  B ( Calorimetric  Method  ) 
 )noitasnepmoc( 0 
0 
A-5.2.1  Outline of the Method  2  20 
4  40 
 ehT  eudiser  tfel  retfa  noitanimile  fo  selitalov  fo
6  60 
 muinomma  etanobrac is   devlossid  ni  dellitsid  retaw  ot
8  80 
 hcihw  noitidda  fo  cirucrem  etanaycoiht and   cirref
10  100 
 muinomma  ,etahplus  secudorp a   ylhgih  deruoloc  cirref
3
IS 5316  : 1998 
Add  to  each,  2  ml  of  ferric  ammonium  sulphate  A-6  TEST FOR SULPHUR  COMPOUNDS 
solution (A-5.2.3.1)  and 2 ml of mercury thiocyanate 
solution (A-5.2.3.2)  in that order.  Dilute  to mark and  Two  methods  are  prescribed.  Method  A  shall  be 
mix well.  referee method in case of dispute and Method  B the 
alternative  method. 
Allow  to stand for  I5  minutes,  transfer to the cell of 
spectrophotometer  and measure absorbance of 450 nm  A-6.1  Method  A 
wavelength  with  compensation  solution  in reference 
A-6.1.1  Apparatus 
cell. 
A-5.2.4.2  Preparation of calibration graph  A-6.1.1.1  Nessler cylinders -  50-ml  capacity. 
Plot chloride  content  in micrograms  as abscissae Vs.  A-6.1.2  Reagents 
corresponding  absorbance values as ordinates. 
A-6.1.2.1  Sodium carbonate 
A-5.2.5  Determination 
A-6.1.2.2  Concentrated  hydrochloric  acid -  See 
A-5.2.5.1  Weigh  suitable  mass  of  ammonium  IS 265. 
carbonate containing  50 to I50  pg of chloride (as Cl) 
accurately  to  I  mg  and  transfer  into  a  platinum  A-6.1.2.3  Bromine water 
evaporating  dish.  Wet the sample with 20 to 30 ml of 
distilled  water  and  add  about  IO  mg  of  sodium  Shake water with a little liquid bromine till  the water 
carbonate,  heat  it on a water  bath until  almost  dry.  itself  becomes reddish brown  in colour  and a slight 
Repeat wetting and heating process. Finally  add a few  excess of liquid bromine remains at the bottom. 
drops  of  sulphuric  acid  solution  (A-5.2.3.5)  and 
A-6.1.2.4  Dilute hydrochloric acid 
dissolve  in  20-30  ml  distilled  water and add about 
IO mg of  sodium  carbonate.  Transfer  quantitatively 
Approximately  1 N. 
into a’ IOO-ml  volumetric  flask,  make up to the mark 
with distilled  water and mix well.  A-6.1.2.5  Barium chloride solution 
Filter through Whatman  No. 41 filterpaperanddiscard  Approximately  10 percent (w/v). 
a small volume of initial  filtrate. 
A-6.1.2.6  Standard sulphate solution 
Transfer  suitable  volume  (25  to 40 ml)  into a 50-ml 
volumetric  flask, and 2 ml ferric ammonium  sulphate  Dissolve 0.148 g of ignited sodium sulphate (Na2S04) 
solution  (A-5.2.3.1)  and 2 ml of mercury thiocyanate  in water and dilute  to 1 000  ml. One millilitre  of the 
solution  (A-5.2.3.2)  in that order, dilute  to mark and  solution contains 0.1 mg of sulphate (as Sod). 
 
 
mix well. 
 
  A-6.1.3  Procedure 
Allow  to stand for  I5  minutes,  transfer to the cell of 
the spectrophotometer  and measure absorbance at 450  Dissolve 2 g of the sample in 20 ml of water, add about 
nm  wavelength.  Also  determine  chloride  in  blank  10 mg of sodium carbonate and evaporate to dryness. 
using same volume of distilled  water as that of aliquot  Dissolve the residue in a slight excess of concentrated 
used for test with same volume of all other reagents.  hydrochloric acid, add 2 ml of bromine water and again 
evaporate to dryness.  Dissolve  the residue in 4 ml of 
A-5.2.6  Culcuiutions and Expression of Results  water and  I ml of dilute hydrochloric  acid. Filter  in a 
Nessler cylinder through a small filter,  wash with two 
The chloride  content is calculated  from the formula: 
2-ml portions of water, dilute to 10 ml and add  I ml of 
Chloride  (as Cl).  percent by mass = M:k  AoM&  barium  chloride  solution.  Dilute  to 50  ml  and mix. 
Carry  out a control  test in another  Nessler  cylinder 
where  using 0.4 ml in case of Grade   1 material,  or I .O in case 
MI  =  mass  in  micrograms  of  chloride  of Grade 2 material,  of standard sulphate solution  in 
corresponding  to  absorbance  of  test  place of the sample and the same quantities of another 
solution,.  reagents  in  the  same  total  volume  of  the  reaction 
M?  =  mass  in  micrograms  of  chloride  mixture. 
corresponding  to absorbance of blank 
solution, and  A-6.1.4  The limit prescribed in Table  1 shall be taken 
MO =  mass in grams of ammonium  carbonate  as not having been exceeded if the turbidity  produced 
in the test with  the material  is not greater  than that 
in the test portion of the aliquot used for 
colour development.  produced in the control tests. 
4
IS 5316 : 1998 
h-6.2  Method  B (Turbidimetric  Method)  negligible  transmission  below  450  nm  and above 
550 nm. 
A-6.2.1  Outline  of the Method 
A-6.2.5  Procedure 
This  describes  a  Turbidimetric  method  for  the 
determination  of  sulphates  and  is applicable  when  A-6’2*5J  calibration 
sulphate content is less than 0.  I percent by mass.  Into  each  of  a  series  of  nine  SO-ml  one-mark 
volumetric  flasks,  place  the  volumes  of  standard 
A-6.2.2  Principle 
sulphuric acid solution (A-6.2.3.4.1)  as shown in the 
Neutralization  of the test portion  (for  alkaline  salts)  following  table: 
with hydrochloric  acid and-making it acidic with slight 
Sulphuric Acid  Corresponding 
excess  of  hydrochloric  acid  and  precipitation  of 
Solution, ml  Mass of SO4, mg 
sulphate  as  barium  sulphate  under  well  defined 
conditions.  Measurement  of  turbidity  using  a  0  0 
spectrophotometer  (or photocolorimeter)  at 470 nm.  5  0.5 
10.0  1.0 
A-6.2.3  Reugents 
15.0  I.5 
A-6.2.3.1  Barium  chloride  20.0  2.0 
25.0  2.5 
A.R.  Barium  chloride  dihydrate  of uniform  particle 
30.0  3.0 
size  between  0.50  and  1.25  mm,  standardized  by 
35.0  3.0 
screening.  It  is  essential  that  all  preparations 
40.0  4.0 
concerning  the  determination  and  standardization 
shall be carried out using a product of the same particle 
To  each  flask,  add  2 ml  of  sodium  carbonate 
size distribution. 
solution  (A-6.2.3.2)  and 5  ml  of  hydrochloric  acid 
A-6.2.3.2  Sodium  carbonate  solution,  approx  0.5  solution  (A-6.2.3.3.1),  stir, dilute  to mark  and mix 
mol/l.  well. 
A-6.2.5.2  Turbidimetric  reaction 
A-6.2.3.3  Hydrochloric  acid solution, approx I m&l. 
Transfer 25.0 ml of each of the solution dxcept the first 
A-6.2.3.3.1  Hydrochloric  acid  solution,  approx  6 
to separate dry IOO-ml beaker each containing  0.15  g 
mol/l. 
barium  chloride  (A-6.2.3.1).  Stir  by hand for 1 min 
A-6.2.3.4  Standard  sulphuric  acid  solution,  0.05  at  the  rate  of2  cev/s,  allow  to  stand for I5 min at 
mol/l.  27 f  2’C. 
Prepare  approximately  I mol/l solution by pouring 56  Stir by hand and transfer a sufficient  quantity  of each 
ml  of  concentrated  sulphuric  acid  into  944  ml  of  of the solutions to a cell of the spectrophotometer  and 
distilled  water.  Dilute  50 ml of th i s solution to I 000  measure the absorbance at 470  nm wavelength.  Use 
ml  in a volumetric  flask  which  give s  approximately  compensation  solution  to  adjust  optical  zero  of 
0.05 mol/l solution. Standardize this against a standard  spectrophotometer. 
sodium  carbonate  solution  (0.05  mol/l)  prepared  by 
A-6.2.5.3  Preparation  of calibration  graph 
dissolving A.R.  Sodium carbonate dried at 260-27O’C. 
Plot a graph with SO4 content in mg as abscissae Vs. 
Dissolve  1.324  9  g  in  distilled  water,  transfer 
corresponding  absorbance  values  as ordinates.  It 
quantitatively  into a 250-ml  flask,  make  up to mark 
and mix well.  should be noted that the calibration  curve is linear only 
above 0.5 mg SO4. 
A-6.2.3.4.1  Standard  sulphuric  acid  solution,  0.1 
A-6.2.6  Determination 
sulphate per ml. 
A-6.2.6.1  Test portion 
Transfer 20.8 ml of 0.05 moln standard sulphuric acid 
Weigh to the nearest I mg a quantity of the test sample 
solution  (A-6.2.3.4)  into  a  I  litre  volumetric  flask, 
of ammonium  carbonatecontaining  to4 mg of SO4 and 
dilute  to mark with distilled  water and mix well.  one 
transfer into a platinum  evaporating  dish (A-6.2.4.2), 
millilitre  of this solution = 0. I mg SO,. 
wet the sample with  20-30  ml of distilled  water  and 
A-6.2.4  Apparatus  heat  on  the  water  bath to almost dryness. Then add 
5 ml of hydrochloric  acid solution  (A-6.2.3.3.1)  and 
A-6.2.4.1  Standard  laboratory  apparatus 
20-30  ml of distilled water and heat again on the water 
A-6.2.4.2  Platinum  evaporating  dish, @ml  capacity.  bath for a few minutes. 
A-6.2.4.3  Spectrophotometer  or  photoelectric  Transfer  into 50 ml one-mark  volumetric  flask,  cool 
absorptiometer  fitted  with  filters  giving  only  a  and make up to the mark with distilled water. If turbid, 
5