METHODS MANUAL OF CHEMICAL TESTS FOR  HYDRAULIC CEMENT (IS: 4032-1985)

PARTIAL ANALYSIS

 

Determination of Free-Lime

 

           The Free Lime analysis of Clinker & Cement sample is done

Chemicals Required: 1. Ethylene Glycol: Concentrated

2. Bromocresol Green: 0.1gm of Bromocresol Green

                 powder in 100ml absolute alcohol.

3. 0.1N Hydrochloric Acid: 8.5ml conc.HCl in + 991 ml

                 distilled water.

 

Procedure: 1. Weigh and transfer 1.0gm of clinker sample in a dry 100ml. conical flask.

2. Add 25 to 30ml of Ethylene Glycol (containing less than 1% of moisture) close the mouth of the flask with a cork. Mix the content by swirling the flask.
3. Heat the conical flask on the water bath, which is maintained at 60 – 70⁰C for half an hour.
4. Shake the flask vigorously after every 5mins. to prevent the formation of

lumps.

5. Then filter it through two Whatmann No.40 filter papers using Buckner funnel by suction machine.
6. Wash the flask and residue on the filter paper with about 50ml. of Ethylene Glycol.
7. Titrate the washing and filtrate with std. (0.1N) HCl using Bromocresol Green as an indicator (3 drops).
8. End point from blue to green than to yellow.

 

                          % Free Lime = No. of cc of (0.1N) HCl  * 0.28    

Calculation:

Precaution: The flask, funnel used in this method should be perfectly dry i.e. free from moisture.

Determination of Insoluble residue (IR) & Sulfuric anhydride (SO₃)

 

           The IR & SO₃ analysis of Cement & Gypsum sample is done

Chemicals Required: 1. Hydrochloric Acid (1:1)

2. Barium Chloride (10%)
3. Sodium Carbonate (2N): 10.6 gms of pure dry Na₂CO₃ is

                    dissolved in dist. water and made up to 100ml .

4. Hydrochloric Acid (1:99)

 

         Procedure: 1. Weight and transfer 1gm of sample in a 250ml conical beaker.

2. Wash the sides of the beaker and moisten the sample with about 10 ml of hot distilled water. Then add to it about 20 ml of 1:1 HCl.
3. Dissolved the sample and add about 120-130 ml of distilled water.
4. Heat to boil the solution on a hot plate about 5-7 minutes.
5. Then remove it from heater and filter it through Whatman-40 .
6. Wash the beaker and the residue on the filter paper properly (3-4 times). Then give washing to filter paper until the residue free from chloride.
7. Then take the precipitate on the filter paper for the test of IR and filtrate for SO₃. Test.

                   Insoluble Residue

8. Transfer the residue along with the filter paper in the original beaker. Then add 30 ml of 2(N) Na₂CO₃ in it and keep it for digestion for 30 mins.
9. Then filter again through the another Whatman-40 filter paper.
10. Wash the beaker and the filter paper properly (3-4 times).
11. Rub the beaker with the filter paper so that no residue left in the beaker.
12. Give 2-3 washings of 1:99 HCl on the both filters on the funnel that the residues free from Na₂CO
13. Then give washings of hot distilled water till it is free from chloride ions.
14. Take a clean pre-weighed Pt –crucible and transfer the residue along with the filter paper in the crucible.
15. Dry and charring it upon a heater or at the doorstep of the muffle furnace.
16. Ignite it about 40mins. in a muffle furnace at temp. of 900-1000°C.
17. Bring out the crucible from the furnace and keep into the decicator for 15 mins.
18. Take the final weight and calculate IR %.

% Insoluble Residue = Weight Difference *100

Sulphate as SO₃

2. Keep the filtrate for boiling on the hot plate until the volume becomes about 150ml-200ml.
3. To the boiling solution add about 30-50 ml of hot BaCl₂
4. Allow it to boil for 5-7 minutes.
5. Remove it from hot plate and allow it to settle for 4 hrs.(preferable overnight).
6. Then filter it through Whatmann No 42 filter paper.
7. Wash filter paper with hot distilled water till it is free from chloride ions.
8. Take the precipitate along with the filter paper in a pre-weighed crucible.
9. Dry and charring it upon a heater or at the doorstep of the muffle furnace.
10. Ignite it about 40mins. in a muffle furnace at temp. of 800-900°C.
11. Bring out the crucible from the furnace and keep into the decicator for15 mins.
12. Take the final weight and calculate SO₃%

Determination of Total Sulphate

 

The Total Sulphate analysis of Clinker, Slag & Gypsum  sample is done

 

           Chemicals Required: 1. Hydrochloric Acid (1:1)

2. Barium Chloride (10%)
3. Sodium Carbonate (Solid)
4. Potassium Nitrate(Solid)

 

Procedure: 1. 1.0 gram of sample is weighed in a clean platinum crucible and add

about 1-2 gram of Na₂CO₃ into the crucible.

2 Mix it thoroughly and add pinch of Potassium Nitrate, which act as

a catalyst.

3. Then cover the mixture with about 1.0 gm of Na₂CO_3, forming a

uniform layer.

4. Fuse the mixture with a lower flame for 30 minutes.

[Note: Cover the crucible with a Pt. plate while fusion takes place.]

5.   Take the crucible out and quench it with water.
6. Extract the whole mass in a 250ml beaker with the help of 20ml of

conc.HCl and 100-150 ml of hot distilled water.

7. Clean the crucible with distilled water in the same beaker.
8. Filter the solution with Whatmann no. 40 filter paper in a 250ml or

• 400ml beaker. Give 3-4 washing with hot distilled water. (throw the
• precipitate).

9. Keep the filtrate for boiling on the hot plate until the volume becomes about 150ml-200ml.
10. To the boiling solution add about 30-50 ml of hot BaCl₂
11. Allow it to boil for 5-7 minutes.
12. Remove it from hot plate and allow it to settle for 4 hrs.(preferable overnight).
13. Then filter it through Whatmann No 42 filter paper.
14. Wash filter paper with hot distilled water till it is free from chloride ions.
15. Take the precipitate along with the filter paper in a pre-weighed crucible.
16. Dry and charring it upon a heater or at the doorstep of the muffle furnace.
17. Ignite it about 40mins. in a muffle furnace at temp. of 800-900°C.
18. Bring out the crucible from the furnace and keep into the decicator for15 mins.
19. Take the final weight and calculate SO₃%

 

              % SO₃ = Weight Difference * 34.3

 

Determination of Phosphate

           The Phosphate analysis of Cement & Gypsum  sample is done

Chemicals Required: 1. Nitric Acid (1:1)

2. Ammonium Nitrate (Solid)
3. Ammonium Molybdate (25%)
4. Potassium Nitrate (1%)
5. Sodium Hydroxide (0.25 N) : Dissolve 10 gms.of

• Sodium Hydroxide in 1 liter of distilled water.

6. Phenolphthalein: Dissolve 1gram of Phenolphthalein in

100ml of ethanol.

7. Hydrochloric Acid (0.5N): 42.5ml of conc. hydrochloric

acid + 957.5 ml of distilled water

Procedure: Acid Soluble Phosphate:

1. Weigh 1gm. Sample into an evaporating dish.
2. Add 20ml of 1:1 HNO₃ and heat it to evaporate.
3. Then bake it in oven about 10-15mins.and again add 20ml 1:1 HNO₃.
4. Warm it about 2-5mins then filter it by Whatmann filter paper no.40

• and give 1- 2 washings.

5. Take the filtrate and add 10gm NH₄NO₃. Then heat it gently.
6. Add 50ml of Ammonium Molybdate solution (25%).
7. Shake it vigorously and keep it for precipitation about 1-2 hrs.
8. After that filter it by Whatman-40 filter paper. Then give washing to

• the flask 5times by 1% KNO₃ and at the filter paper 8-10 times.

[ Note: Checking is done by taking small amount filtrate and add

phenolphthalein and add 1drop NaOH, if solution becomes violet that

means washing is complete.]

9. Transfer the whole filtrate in the original flask.
10. Add cold water and add 10ml N/4 NaOH.
11. Then after adding phenolphthalein titrate it with N/2 HCl.

                 Water Soluble Phosphate:

               1. Takes 1gm sample in a conical beaker and add water 100ml.

2. Heat to boil the solution and then keep it for digestion 20 – 30mins.
3. Filter it by Whatmann filter paper no.40 then add 5ml-conc.HNO₃ and

• warm it about 2-5mins

4. Then filter it by Whatmann filter paper no.40 and give 1- 2 washings.
5. Take the filtrate and add 10gm NH₄NO₃. Then heat it gently.
6. Add 50ml of Ammonium Molybdate solution (25%).
7. Shake it vigorously and keep it for precipitation about 1-2 hrs.
8. After that filter it by Whatman-40 filter paper. Then give washing to

• the flask 5times by 1% KNO₃ and at the filter paper 8-10 times.

[ Note: Checking is done by taking small amount filtrate and add

phenolphthalein  and add 1 drop NaOH, if solution becomes violet

that means washing is complete.]

9. Transfer the whole filtrate in the original flask.
10. Add cold water and add 10ml N/4 NaOH.
11. Then after adding phenolphthalein titrate it with N/2 HCl.

Determination of Chloride

 

           The Chloride analysis of limestone, kiln feed and raw meal sample is done

Chemicals Required: 1. Nitric Acid (1:1)

2. Silver Nitrate Solution (0.05N): Dissolve 8.5gm of

Silver Nitrate in 1 liter of distilled water

3. Ammonium Thiocyanate (0.05N): Dissolve 3.90gm of

Silver Nitrate in 1 liter of distilled water

4. Ferric alum( 10%): Dissolve 10 grams of ferric alum in

                   a boiling mixture of 20ml of HNO₃ (6N)and 80ml of water.

 

Procedure:  1. Take 2 gm of sample in a 250ml conical beaker and add 40ml

water in that.

2. Add 20ml (1:1) HNO₃ into that and shake it nicely.
3. Then boil it for 5mins and digest it for 30mins.
4. Filter it by Whatman-41 filter paper and then give washings with distilled water and collect the filtrate and make it cool.
5. Add 5ml (exactly) N/20 AgNO₃ to the filtrate for converting all Cl- into AgCl.
6. Add 3ml (exactly) ferric alum solution as indicator.
7. Then titrate with N/20 Ammonium Thiocyanate solution to a reddish brown end point.
8. Carry out a blank titration by taking same quantity of distilled water, nitric acid, N/20 AgNO₃, ferric alum indicator and titrate with N/20 Ammonium Thiocyanate solution.
9. The end point will be reddish brown.

[ Note: It will be better if the blank titration is done before doing the sample titration]

Determination of Total Carbonate

 

            The carbonate analysis of limestone, kiln feed and raw meal sample is done

Chemicals Required: 1. Hydrochloric Acid(0.5N): 4.5 ml of hydrochloric acid +

                                                 95.5ml of distilled Water.

2. Sodium Hydroxide (0.25 N) : Dissolve 10 gms.of

• Sodium Hydroxide in 1 liter of distilled water.

3. Phenolphthalein: Dissolve 1gram of Phenolphthalein in

100ml of ethanol.

4. Thymolphthalein: Dissolve 0.2gram of Thymolphthalien

in 300ml of alcohol and dilute with water to 500ml.

            Total Carbonate:

            Procedure:   1.  Weigh 0.5 gm of sample into a 250ml. Conical flask.

2. Wash the side of the conical flask with some amount of distilled water and add 25.0 ml of N/2 HCl.
3. Heat the solution to boiling on a hot plate for about 2-3 min. after boiling start.
4. Remove from the hot plate and wash the sides of the conical flask with distilled water .
5. Add 3-4 drops of phenolphthalein indicator and titrate (in hot condition) against N/4 NaOH to a pink end.

Magnesium Carbonate:                                                                                                             

Procedure: 6.  After getting the pink end point in the case of T.C. analysis add 3.0

1. of NaOH in excess.
2. Add 2-3 drops of thymolphthalein as an indicator. The color of the

solution will turn violate.

• Keep it for boiling on a hot plate. As soon as the boiling starts remove the flask for cooling upto room temp.
• Then titrate against N/2 HCl till violet color disappears. This titration is known as “BACK TITRATION”.

Precaution: The above reaction c. is a reversible reaction hence the back titration is carried out as fast as possible. In this process the trace of the violet color reappears.

Determination of Lime [Rapid Lime Method]

 

           The Lime analysis of Clinker, Cement, Gypsum & Slag sample is done

           Chemicals Required: 1. Hydrochloric Acid (1:1)

2. Sulfuric Acid (1:1)
3. Ammonium Hydroxide(1:1)      

• Ammonium Oxalate

5. Oxalic Acid(10%)
6. Methyl Orange: (0.1%)

                7.Potassium Parmaganate(0.03N): 0.94gm of Potassium

                   Parmaganet per liter of distilled water in a dark bottle

and allow to stand for a week before use.

 

         Procedure:  1.   Weight and transfer 0.5gm of sample in a 500ml.beaker.

2. Wash the sides of the beaker and break the lumps of the sample with about 10ml of distilled water and add about 20 ml of 1:1 HCl.
3. Dissolved the sample and add about 250 ml of distilled water.
4. Heat the solution to boil on a hot plate.
5. Add 1-2 drops of methyl orange as an indicator after 2-3 minutes of boiling.
6. It will turn the solution into orange-red colour.
7. Then neutralize the solution by adding 1:1 NH₄OH drop by drop till the red colour just disappears.
8. Give 4-5drops Oxalic acid until the solution becomes some reddish colour so that the pH of that solution became just 6.5–6.7.
9. If red colours do not come add 2-3 drops of methyl red indicator

[Note: Here methyl red is added because the pH range of methyl

red is 6.3 – 4.3 so it can show when the pH is 6.3 of solution.

But methyl orange(2.8 – 4.8) can not show 6.3]

10. Then add 25–30 ml of hot 5% Ammonium oxalate, white precipitate of Calcium oxalate will formed.
11. Allow it to boil for 5-10 min.
12. And remove it from hot plate and allow it to settle for 15 min.
13. Filter through Whattman no.41 filter paper.
14. Wash the precipitate with hot distilled water about 5-6 times.
15. Then take 100ml 1:1 H2SO4 and about 250 ml of distilled water in the original beaker and heat it in about 75 – 80⁰
16. Transfer the residue in the solution and titrate against standard KMNO₄

 

% CaO = Titre Volume * Factor

[Note: HCl converts all elements into chloride form. Then medium is made alkaline, because Ca- oxalate in acidic condition remains as dissolved in the solution. But in alkaline medium it is ppt.  The size of the ppt  particles are maximum when medium is just alkaline.  Excess addition of NH₄OH then ppt.  This causes the slow filtration.  That is why the addition of excess NH₄OH is avoided.]

FULL  ANALYSIS

 

Ammonium Chloride Method

 

             The Complete analysis by Ammonium Chloride method of Cement (acid soluble), Clinker sample is done

         Chemicals Required: 1.  Hydrochloric Acid: Concentrated, (1:1),(1: 99)

2. Ammonium Chloride (Solid)
3. Potassium Pyrosulphate (Solid)
4. Ammonium Hydroxide (1:1)
5. Bromine Water (3.66% by weight)
6. Sulfuric Acid: Concentrated, (1:1)
7. Hydrogen Floride (Concentrated)
8. Buffer Solution (pH=10): 70gm of ammonium chloride in 570 ml ammonium hydroxide and make upto 1 litre by distilled water
9. Methyl Red: 1 gm of methyl red in 100ml of ethanol
10. Eriochrome Black-T: 100mg.of eriochrome black–T

in 10g .of sodium chloride.

11.Potassium permanganate (approx. 0.1N): Dissolve

     about 3.2grams KMnO₄ in water. Boil for 5 mins. Filter .

cool ,and standardize against sodium oxalate.

12. Ethylene Di amine Tetra Acetic Acid (M/100): 3.7224

      gm dissolve in 400 ml warm distilled water, cool it, add

600ml distilled water.

 

Procedure: 1.  Weigh out 0.5gm of sampleand 0.5gm (appox.) ammonium

chloride  in a 100 ml beaker and mix up properly with a glass rod.

2. Then add 10cc of concentrated HCl into it.
3. Dissolve it with the help of glass rod, cover the beaker with a watch glass and keep on a hot plate of temp. 70-80^O for 30-35 mins.

[Note: During evaporation keep 2-3 wire gauge to prevent boiling

and ensure that there is no black particle]

4. When it forms jelly like bring back from the hot plate and cool it.
5. Then add 10ml.1:1 HCl in to it.
6. Filter through Whattman No.41 filter paper in a 400ml beaker.
7. Give 3-4 1:9 HCl washing and then 8-10 hot distilled water washings till it is free from chloride ion.
8. Collect the residue 1 on the filter paper and the filtrate 1.

 

Residue 1: (For Silica)

9. Filter paper containing residue is transferred in a pre-weighed (C1) crucible, dried, ignited and ash at 900 – 1000⁰C in a furnace.
10. Bring out the crucible from the muffle furnace and keep it in a desiccator for 15 mins and then weigh the crucible (C2).

 

                                         SiO₂ (M)+ R₂O₃ = (W1)= (C2 – C1) 

                         [Note: Some R₂O₃  remains with SiO₂]

2. Then the material in the crucible is moisten by 1-2 drops of water and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.
3. Heat it about to dryness until HF completely reacts with silica.

When the fumes will stop that means reaction is over.

4. Keep the crucible 2-3 minutes on furnace door and then keep it in

900 – 1000⁰C muffle furnace for 15 mins.

5. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C3).

 

SiO₂ = (W2) =W1 – (C3 -C1)

[Note: – Deduct I.R% from SiO₂% to get the correct SiO₂% in case of PPC]

Reaction:

HCl decomposes silicates into H₂SiO₃ and SiCl₄. The acid solution of decompose silicates is evaporated to dryness on water bath (i.e. at low heat) to separate the gelatinous silicic acid, SiO₂.xH₂O as insoluble silica, which is partially dehydrated(the residue is heated at 110⁰C) it is remains insoluble.

Then the residue is extracted with hot and dilute HCl to remove salt of Fe, Al and other metal, which may be present. The greater portion of the silica remain undissolved with a small amount of H₂SiO₃ that has escaped dehydration is filtered off. The residue is ignited in Pt crucible at 1000⁰C to SiO₂.

 

Filtrate 1: (For Residual Oxide)  

15. To the filtrate 1 add about 5cc of saturated bromine water to it.
16. Allow it to boil till the excess bromine water is expelled off.

[Note: This operation is necessary to convert Fe⁺⁺ into Fe⁺⁺⁺ ions as

bromine water an oxidising agent.  As compared to Fe⁺⁺ ions

Fe⁺⁺⁺ions’ hydroxide has a lower solubility product]

17. After this 20ml of 10% NH₄Cl is added or 3-4gm of solid NH₄Cl is added.

[Note: NH₄Cl is used to prevent the ppt. of hydroxides of the

members of the subsequent groups by lowering the concentration

of OH ^– ions due to the common ion of NH ⁴⁺(i.e. common ions

effect)].

18. Add 2-3 drops of methyl red and then (1:1) NH₄OH solution drop by drop till the solution becomes yellow i.e. till complete precipitation of R₂O₃ group as hydroxide. Then boil for a minute remove excess of ammonia.
19. Allow the precipitate to settle, and then filter it by Whatman no. 41 filter paper.
20. Give washings [5-6] of hot NH₄NO₃ and then 5-6 washings of cold distilled water.

             [Note: NH₄NO₃ wash is given to avoid colloidal formation in R₂O₃

precipitate to avoid complete drying of precipitate between

washings]

21. Collect the residue 2 on the filter paper and the filtrate 2.

Residue 2: (For R₂O₃)

22. Filter paper containing residue is transferred in a crucible which contain R₂O₃ of silica, dried, ignited it for 40 min. in a 900 – 1000⁰C muffle furnace.
23. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C4)

 

              SiO₂ + R₂O₃(M) = (W3) = ( C4 –C1)  

[Note: Some SiO₂ remains with R₂O₃]

 

         If W3 < 0.05 gm(10%).

24. Then the material in the crucible is moisten by 1-2 drops of water

and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.

25. Heat it about to dryness until HF completely reacts with silica.

(When the fumes will stop that means reaction is over.)

26. Keep the crucible 2-3 minutes on furnace door and then keep it in

900 – 1000⁰C muffle furnace for 15 mins.

27. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C5).

28. Keep this residue 3 for TiO₂ estimation.

Residue 3: (Titanium)

22. To the material in the crucible add 3-5gm of potassium

     pyrosulphate (K₂S₂O₇)   and then fuse it at low flame.

23. Keep the crucible to cool and extracted the fused material with hot distilled water.

24. Keep on the hot plate till the material gets dissolved.

25. Take the extract solution in the 250 ml beaker and give washings to the crucible.

26. Filter the solution with Whatmann no. 40/41 filter paper, and take the filtrate in 200 ml volumetric flask.

27. Add about 20 ml of concentrated H₂SO₄ in the 200 ml volumetric flask carefully and make the solution cool.

28. Add 3ml Ortho Phosphoric Acid and then 5ml of H₂O, a yellow

colour solution will observe.

29. Make up the volume upto the mark by distilled water.
30. In UV Spectrometer, set Wave Length 410, Concentration 11.4.
31. First put the blank sample inside and align the mark.

[Note: Blank solution is prepared in same procedure only sample

solution is not added here.]

32. Adjust the reading 0 with the blank sample solution
33. Then put the sample solution inside and take the reading.

 

% TiO₂= Reading * 0.04

 

     If W3 > 0.05 gm (10%)

34. To the material in the crucible add 3-5gm of potassium pyrosulphate (K₂S₂O₇) and then fuse it at low flame.

35. Keep the crucible to cool and extracted the fused material with hot distilled water.

36. Keep on the hot plate till the material gets dissolved.

37. Take the extract solution in the evaporating dish and give washings to the crucible.

38. Add about 20 ml of concentrated H₂SO₄ in the dish carefully.

39. Then keep the evaporating dish on the hot plate till white fumes appears.

40. Then take out the evaporating out and filter through Whatman no. 41 filter paper.

41. Collect the filtrate in 200 ml volumetric flask.  Give sufficient washings with hot distilled water.

42. Keep  the filtrate 3 for titanium estimation.

43. Ignite the residue in a previously weighed platinum crucible(C1) at 900-1000° C for 30-40 mins.
44. Bring out the crucible from the muffle furnace and keep it in a desiccator for 15 mins and then weigh the crucible (C6).
45. Then moisten it by1-2 drops amount of water and add 1drop

conc. H₂SO₄ and then add 3-5ml of HF.

46. Heat it about to dryness until HF completely react with silica.

(When the fumes will stop that means reaction is over.)

22. Keep the crucible 2-3 minutes on furnace door and then keep it

in 900 – 1000⁰C muffle furnace for 15 minutes.

23. Bring out the crucible from the muffle furnace and keep it in a desiccator for 15 minutes and then weigh the crucible (C7).

Filtrate 3: (Titanium)

22. Add 3ml Ortho Phosphoric Acid and then 5ml of H₂O A Yellow colour solution will come.
23. Make up the volume by distilled water.
24. In UV Spectrometer, set Wave Length 410, Concentration 11.4.
25. First put the blank sample inside and align the mark.

[Note: Blank solution is prepared in same procedure only sample

solution is not added here.]

26. Adjust the reading 0 with the blank sample solution
27. Then put the sample solution inside and take the reading.

Filtrate 2: (For CaO & MgO)

22. Take the filtrate 2 and make the solution acidic by few drops of

HCl and allow it to boil.

60. Then add to it drop by drop of NH₄OH till the red colour just disappears.
61. Then add 75ml of hot ammonium oxalate solution to it. This will give the precipitate of Calcium oxalate.
62. Boil it for 10minutes.
63. Filter through Whatman No.41 filter paper. Give washings of hot distilled water till it is free from Oxalate ions [Test with AgNO₃ solution].
64. Collect the residue 4 on the filter paper and the filtrate 4 in a 500ml volumetric flask and make it cool.

 

   Residue 4: (For Ca0)

65. Take 100cc of (1:1) H₂SO₄ and 150ml distilled water in the original beaker.
66. Heat it upto 80⁰c
67. Then transfer the filter paper in the beaker containing40.
68. Titrate against Std.KMnO₄ solution.

 

%CaO = Titre Value * Factor

 

Filtrate 4: (For MgO)

69. Make up the volume with water.

[Note: If the solution stays overnight then add slightly 1:1 HCl to

make it acidic.]

70. Take out 100ml of solution in a porcelain dish.
71. Add 3-5ml Tri-Ethanol Amine & 20 – 30ml Buffer solution.
72. Then the solution is stirred vigorously and then a pinch of Eriochrome Black-T indicator is added till the solution becomes light violet.
73. Titrate against Std. EDTA solution.

 

%MgO= Titre Value * 0.403 * Factor

 

 

Determination of Fe₂O₃

 

           Chemicals Required: 1.  Hydrochloric Acid (1:1)

2. Stannous Chloride: Stannous chloride + 10ml HCl + 990ml distilled water + few pieces of metallic tin.
3. Mercuric Cloride:56 gm in 1litre of distilled water.
4. Titrating Mixture: 150ml H₂SO₄ + 150ml H₃PO₄ + 700ml distilled water
5. Barium Di-phenyl amino sulphonate:3gm in 100ml distilled water.
6. Potassium Dichromate: Dissolve 4.9032 grams (dried at 150⁰ C) in water and dilute to one litre.

 

            Procedure:   1. Weigh and transfer 0.5gm of sample in a 250ml beaker.

2. Wash the sides of the beaker with about 10-15 hot distilled water
3. Break the lumps of the sample with the glass rod.
4. Add 20ml of 1:1 HCl to it and add about 50ml of distilled water.
5. Allow it to boil for 4-5minutes on hot plate.
6. Then add drop by drop of SnCl₂ solution to reduce [ferric ions become ferrous ions] the solution that means the colour will just disappear.

[Note: Avoid addition of SnCl₂ solution in excess.]

7. Then cool the solution.
8. Add 20ml of HgCl₂ and keep it for 5 minutes. Then add 10 c.c. of titrating mixture.
9. Then titrate against standard K₂Cr₂O₇ solution using 2-3 drops of Barium Di-Phenyl amine Sulphonate (BDS) solution.
10. Titrate until the violet colour comes.

Significance of SnCl₂, H₃PO₄.

SnCl₂: SnCl₂ is a reducing agent. It reduces FeCl₃ to FeCl₂. Its addition in large excess is avoided as it causes the reduction of Hg₂Cl₂ to Hg. This spoils the analysis.

Hg₂Cl₂   + SnCl₂ (excess) —-2 Hg + SnCl₄

If more then one drop of SnCl₂ is added in excess then add a little KMnO₄ soln. Till the yellow colour reappears. Then repeat the reduction.

 

H₂SO₄:  In presence of H₂SO₄, K₂Cr₂O₇ acts as an oxidising agent.

 

H₃PO₄:   In the titration of K₂Cr₂O₇ soln. It is necessary to prevent the formation of ferric ions. For this purpose H₃PO₄ is used.

 

Significance of the factor of K₂Cr₂O₇Soln.

K₂Cr₂O₇    =   6FeSO₄     =   3 Fe₂SO₄    =   3 FeSO₄

294.18         6 (151.85)      3 (394.7)          3 (159.7)

Let the strength of the K₂Cr₂O₇Soln. be N/y and ‘x’c.c be the volume of K₂Cr₂O₇ be consumed at end point.

i.e. 1000cc of soln. contains K₂Cr₂O₇ = 49.03/y gm.

Therefore x c.c soln. contains  (49.03 * x )/(y * 1000) gm. K₂Cr₂O₇.

i.e. 0.5 gm of sample contains  (49.03 * x )/(y * 1000) gm. K₂Cr₂O₇.

Since we take 0.5 gm of the sample for analysis, therefore the quantity of Fe₂O₃ in 0.5 gm of the sample :

In 294.18 gm K₂Cr₂O₇,  Fe₂O₃ isà 3 * 159.7 gm.

In (49.03 * x )/(y * 1000) gm. K₂Cr₂O₇, Fe₂O₃ is à (3*159.7*49.03*x)/(294.18*y*1000) gm

(i.e. in 0.5 gm of the sample)

In 100gm of sample, Fe₂O₃ is à 3 * 159.7 *49.03 *x * 2 * 100) / (294.18 * y * 1000) gm.

Or  % Fe₂O₃ = (15.97 * x)/y

% Fe₂O₃ = F * x

[ Where F is the factor = 15.97/y of the standard K₂Cr₂O₇ soln.]

 

The N/y is kept in such [i.e. N/15.97] that factor of the soln. becomes 1. That is no. of ml. of K₂Cr₂O₇ soln. consumed directly gives the percentage of Fe₂O₃ in the sample.

Determination of Loss of Ignition [L.O.I]

 

For Clinker, Cement

Procedure: 1.   Weigh out 1.0gm of air-dried sample at 110⁰C for 45 min to 1hour,

into a pre-weighed crucible.

2. Keep it in a muffle furnace at 950-1000⁰C for 30 mins.
3. The sample must be heated slowly at first to prevent mechanical loss arising from

sudden evolution of CO₂.

4. Repeat the process for 5mins until the weight of crucible is constant to 0.2mg.
5. Take the final weight of the crucible.

 

LOI= Weight Difference * 100

 

 

For Gypsum

Procedure: 1.   Weigh out 1.0gm of air-dried sample at 70⁰C for 45 min to 1hour,

into a pre-weighed crucible.

2. Keep it in a muffle furnace at 240⁰C for 30 mins.
3. The sample must be heated slowly at first to prevent mechanical loss arising from

sudden evolution of CO₂.

4. Repeat the process for 5mins until the weight of crucible is constant to 0.2mg.
5. Take the final weight of the crucible.

 

LOI= Weight Difference * 100

 

 

 

Fusion Process

 

           The Complete analysis by Fusion method of Limestone, Kiln Feed, Raw Meal, Fly Ash, Slag( Acid Insoluble), Bauxite, Iron Ore & Sand Stone sample is done

         Chemicals Required: 1.  Hydrochloric Acid: Concentrated, (1:1),(1: 99)

2. Ammonium Chloride (Solid)
3. Potassium Pyrosulphate (Solid)
4. Ammonium Hydroxide (1:1)
5. Bromine Water (3.66% by weight)
6. Sulfuric Acid: Concentrated, (1:1)
7. Hydrogen Floride (Concentrated)
8. Buffer Solution (pH=10): 70gm of ammonium chloride in 570 ml ammonium hydroxide and make upto 1 litre by distilled water
9. Methyl Red: 1 gm of methyl red in 100ml of ethanol
10. Eriochrome Black-T: 100mg.of eriochrome black–T

in 10g.of sodium chloride.

11. Potassium permanganate (approx. 0.1N): Dissolve

     about 3.2grams KMnO₄ in water. Boil for 5 mins. Filter .

cool ,and standardize against sodium oxalate.

12. Ethylene Di amine Tetra Acetic Acid (EDTA):7224 gm

     dissolve in 400 ml warm distilled water, cool it, add 600ml

distilled water.

13. Sodium Carbonate (Solid)

 

Procedure: 1. 0.5 gram of sample is weighed in a clean platinum crucible.

[Note; in case of fly ash or coal sample it is better to take 0.8-1.0

gm of sample in a pre-weighed crucible and the heat the crucible

in a very  low flame for 5-10 mins (cover the crucible with a

platinum lid). Make it cool in a dissecator. Now take out material

from the crucible keeping 0.5gm into it.]

2. Add  about 1-2 gram of Na₂CO₃ into the crucible.
3. Mix it thoroughly and then cover the mixture with about 2-3 gms of

Na₂CO₃ forming a uniform layer.

4. Fuse the mixture with a lower flame for 10-15 minutes. (Shake the

crucible at   5minutes time intervals)

5. Then keep the crucible at higher flame for 30-40minutes.

[Note: Cover the crucible with a Pt. plate while fusion takes place.]

6. Take the crucible out and quench it with water.
7. Extract the whole mass in 25-30ml of 1:1HCl in a evaporating dish.
8. Clean the crucible with distilled water in the same evaporating dish

• on a wire gauge and evaporate to dryness on a hotplate

9. Keep it for baking in oven for 1 hour (temperature 110-130 C).
10. Remove the evaporating dish, add about 30ml 1:1 HCl.
11. Slightly warm on the hot plate and filter it through Whatman no.

• 41 filter paper.

12. Wash the residue 5-6 times with hot water.
13. Collect the residue 1 on the filter paper and the filtrate 1.

Residue 1: (For Silica)

14. Filter paper containing residue is transferred in a pre-weighed (C1)

crucible, dried, ignited and ash at 900 – 1000⁰C in a furnace.

15. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C2).

 

                                   SiO₂ (M)+ R₂O₃ = (W1)= (C2 – C1)

                       [Note: Some R₂O₃  remains with SiO₂]

16. Then the material in the crucible is moisten by 1-2 drops of water

and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.

17. Heat it about to dryness until HF completely reacts with silica.

(When the fumes will stop that means reaction is over.)

18. Keep the crucible 2-3 minutes on furnace door and then keep it in 900 – 1000⁰C muffle furnace for 15 mins.
19. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C3).

 

SiO₂ = (W2) =W1 – (C3 -C1)

 

Filtrate 1: (For Residual Oxide)  

19. To the filtrate 1 add about 5cc of saturated bromine water to it.
20. Allow it to boil till the excess bromine water is expelled off.

[Note: This operation is necessary to convert Fe⁺⁺ into Fe⁺⁺⁺ ions as

bromine water an oxidising agent.  As compared to Fe⁺⁺ ions

Fe⁺⁺⁺ions’ hydroxide has a lower  solubility product]

21. After this 20ml of 10% NH₄Cl is added or 3-4gm of solid NH₄Cl is

added.

[Note: NH₄Cl is used to prevent the ppt. of hydroxides of the

members of the subsequent groups by lowering the concentration

of OH ^– ions due to the common ion of NH ⁴⁺(i.e. common ions

effect)].

22. Add 2-3 drops of methyl red and then (1:1) NH₄OH solution drop by

drop till the  solution becomes yellow i.e. till complete precipitation

of R₂O₃ group as hydroxide.

24. Then boil for a minute remove excess of ammonia.
25. Allow the precipitate to settle, and then filter it by Whatman no. 41

filter paper.

26. Give washings [5-6] of hot NH₄NO₃ and then 5-6 washings of cold

distilled water.

             [Note: NH₄NO₃ wash is given to avoid colloidal formation in R₂O₃

precipitate,  avoid complete drying of precipitate between washings]

27. Collect the residue 2 on the filter paper and the filtrate 2.

Residue 2: (For R₂O₃)

28.  Filter paper containing residue is transferred in a crucible which

contain R₂O₃ of   silica, dried, ignited it for 40 min. in a 900 – 1000⁰C

muffle furnace.

29. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15  mins and then weigh the crucible (C4)

       SiO₂ + R₂O₃(M) = (W3) = ( C4 –C1)

                     [Note: Some SiO₂ remains with R₂O₃]

         If W3 < 0.05 gm.

30. Then the material in the crucible is moisten by 1-2 drops of water

• and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.
• Heat it about to dryness until HF completely react with silica.
• (When the fumes will stop that means reaction is over.)

32. Keep the crucible 2-3 minutes on furnace door and then keep it in

• 900 – 1000⁰C muffle furnace for 15 mins.

33. Bring out the crucible from the muffle furnace and keep it in a

• desiccator for 15 minutes and then weigh the crucible (C5).

34. Keep this residue 3 for TiO₂ estimation.

Residue 3: (Titanium)

                   35. To the material in the crucible add 3-5gm of potassium

                   pyrosulphate (K₂S₂O₇)   and then fuse it at low flame.

                   36. Keep the crucible to cool and extracted the fused material with hot

                           distilled water.

                   37. Keep on the hot plate till the material gets dissolved.

                   38. Take the extract solution in the 250 ml beaker and give washings to

                           the crucible.

                   39. Filter the solution with Whatmann no. 40/41 filter paper, and take the

                          filtrate in 200 ml volumetric flask.

                   40. Add about 20 ml of concentrated H₂SO₄ in the 200 ml volumetric flask

                         carefully and make the solution cool.

41. Add 3ml Ortho Phosphoric Acid and then 5ml of H₂O_2., a yellow

colour solution will observe.

42. Make up the volume upto the mark by distilled water.
43. In UV Spectrometer, set Wave Length 410, Concentration 11.4.
44. First put the blank sample inside and align the mark.

[Note: Blank solution is prepared in same procedure only sample

solution is not added here.]

45. Adjust the reading 0 with the blank sample solution
46. Then put the sample solution inside and take the reading.

 

% TiO₂= Reading * 0.04

 

Filtrate 2: (For CaO & MgO)

47. Take the filtrate 2 and make the solution acidic by few drops of

HCl and  allow it to boil.

48. Then add to it drop by drop of NH₄OH till the red colour just

49. Then add 75ml of hot ammonium oxalate solution to it. This will

• give the precipitate of Calcium oxalate and boil it for 10minutes.

50. Filter through Whatman No.41 filter paper. Give washings of hot

• distilled water till it is free from Oxalate ions [Test with AgNO₃
• solution].

51. Collect the residue 4 on the filter paper and the filtrate 4 in a

• 500ml volumetric flask and make it cool.

   Residue 4: (For Ca0)

52. Take 100cc of (1:1) H₂SO₄ and 150-200ml distilled water in the

• original beaker and heat it upto 80⁰c

53. Then transfer the filter paper in the beaker containing 100cc of (1:1)

• H₂SO₄ and 150-200ml distilled water.

54. Titrate against Std.KMnO₄ solution.

 

%CaO = Titre Value * Factor

 

Filtrate 4: (For MgO)

55. Make up the volume upto the mark with distilled water.

[Note: If the solution stays overnight then add slightly 1:1 HCl to

make it acidic.]

56. Take out 100ml of solution in a porcelain dish.
57. Add 3-5ml Tri-Ethanol Amine & 20 – 30ml Buffer solution.
58. Then the solution is stirred vigorously and then a pinch of Eriochrome

• Black-T indicator is added till the solution becomes light violet.

59. Titrate against Std. EDTA solution.

 

%MgO= Titre Value * 0.403 * Factor

 

    If W3 > 0.05 gm (10%)

                    60. To the material in the crucible add 3-5gm of potassium pyrosulphate

                          (K₂S₂O₇) and then fuse it at low flame.

                    61. Keep the crucible to cool and extracted the fused material with hot

                           distilled water.

                    62. Keep on the hot plate till the material gets dissolved.

                    63. Take the extract solution in the evaporating dish and give washings to

                          the crucible.

                    64. Add about 20 ml of concentrated H₂SO₄ in the dish very carefully.

                    65. Then keep the evaporating dish on the hot plate till white fumes

                          appears.

                    66. Then bring back the evaporating dish and filter through Whatman

                           no.40 filter paper.

                   67. Collect the filtrate in 200 ml volumetric flask.  Give sufficient washings

                          with hot distilled water.

                    68. Keep  the filtrate 3 for titanium estimation.

69. Ignite the residue in a previously weighed platinum crucible (C1) at

• 1000° C for 30-40 mins.

70. Bring out the crucible from the muffle furnace and keep it in a

• desiccator for 15 mins and then weigh the crucible (C6).

71. Then moisten it by1-2 drops amount of water and add 1drop conc.

• H₂SO₄ and then add 3-5ml of HF.

72. Heat it about to dryness until HF completely react with silica.

• (When the fumes will stop that means reaction is over.)

73. Keep the crucible 2-3 minutes on furnace door and then keep it in

• 900 – 1000⁰C muffle furnace for 15 minutes.

74. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 minutes and then weigh the crucible (C7).

 

Filtrate 3: (Titanium)

75. Add 3ml Ortho Phosphoric Acid and then 5ml of H₂O_2. A Yellow

colour solution will come.

76. Make up the volume by distilled water.
77. In UV Spectrometer, set Wave Length 410, Concentration 11.4.
78. First put the blank sample inside and align the mark.

[Note: Blank solution is prepared in same procedure only sample

solution is not added here.]

79. Adjust the reading 0 with the blank sample solution
80. Then put the sample solution inside and take the reading.

 

% TiO₂= Reading * 0.04

 

    Filtrate 2: (For CaO & MgO)

81. Take the filtrate 2 and make the solution acidic by few drops of

HCl and allow it to boil.

82. Then add to it drop by drop of NH₄OH till the red colour just

83. Then add 75ml of hot ammonium oxalate solution to it. This will give

• the precipitate of Calcium oxalate and boil it for 10minutes.

84. Filter through Whatman No.41 filter paper. Give washings of hot

• distilled water till it is free from Oxalate ions [Test with AgNO₃
• solution].

85. Collect the residue 4 on the filter paper and the filtrate 4 in a 500ml

• volumetric flask and make it cool.

   Residue 4: (For Ca0)

86. Take 100ml  1:1 HCl in the original beaker.
87. Take the precipitate on the filter paper (residue 4) into the beaker

• and squeeze and wash the filter paper nicely with the distilled water,
• throw the filter paper.

88. Add 2-3 drops methyl red and make it boil for 10-15 minutes.
89. Then add to it drop by drop of NH₄OH till the red colour just

90. Then add 75ml of hot ammonium oxalate solution to it. This will

• give the precipitate of Calcium oxalate boil it for 10minutes.

91. Filter through Whatman No.41 filter paper. Give washings of hot

• distilled water till it is free from Oxalate ions [Test with AgNO₃
• solution].

92. Collect the residue5 on the filter paper and throw the filtrate.
93. Take 100cc of (1:1) H₂SO₄ and 150ml distilled water in the original

• beaker and heat it upto 80⁰c

94. Then transfer the filter paper in the beaker containing40.
95. Titrate against Std.KMnO₄ solution.

 

%CaO = Titre Value * Factor

 

     Filtrate 4: (For MgO)

96. Make up the volume upto the mark with distilled water.

[Note: If the solution stays overnight then add slightly 1:1 HCl to

make it acidic.]

97. Take out 100ml of solution in a porcelain dish.
98. Add 3-5ml Tri-Ethanol Amine & 20 – 30ml Buffer solution.
99. Then the solution is stirred vigorously and then a pinch of Eriochrome Black-T indicator is added till the solution becomes light violet.
100. Titrate against Std. EDTA solution.

 

%MgO= Titre Value * 0.403 * Factor

 

 

 

Determination of Fe₂O₃

 

            Chemicals Required: 1.  Hydrochloric Acid (1:1)

2. Stannous Chloride: 50gm. Stannous chloride + 10ml HCl

      + 990ml distilled water + few pieces of metallic tin.

3. Mercuric Cloride:56 gm in 1litre of distilled water.
4. Titrating Mixture: 150ml H₂SO₄ + 150ml H₃PO₄ + 700ml

                      distilled water

5. Barium Di-phenyl amino sulphonate: 0.3gm in 100ml

distilled water.

6. Potassium Dichromate: Dissolve 4.9032 grams (dried

at 150⁰ C) in water and dilute to one litre.

 

Procedure: 1. 0.5 gram of sample is weighed in a clean platinum crucible and

about 1-2 gram of  Na₂CO₃ is added

2. Mix it thoroughly and then cover the mixture with about 2-3 gms of

Na₂CO₃ forming a uniform layer.

3. Fuse the mixture at a low flame for 10-15 minutes. Swirl the

crucible after 15 minutes.

4. Then keep the crucible at high flame for 30-40minutes.

[Note: Cover the crucible with a platinum lid while fusion takes place.]

2. After that the first take the lid out and put it in a 400 ml beaker

containing 1:1 HCl(20 ml) and then quench the crucible with

water at its outer side and put it in that same beaker.

3. Extract the whole mass in 25-30ml of 1:1HCl inside the same

400ml beaker.

7. Clean the crucible with distilled water in the same beaker.  Make up the volume to 250 ml with hot distilled water.
8. Allow it to boil for 20-25 minutes on hot plate after adding bromine

water.

9. After that add NH₃ water to it till brown precipitate comes.
10. Again boil it for 2-3 mins and take it out from the hot plate and

filter in a 500-ml beaker with Whatman no.41.  Wash it with distilled water.

11. Throw the filtrate and take the original beaker and dissolve the

residue with 25-ml of 1:1 HCl.

12. Then take the filtrate and place in hot for boiling for 2-5 minutes.
13. Then add drop by drop of SnCl₂ solution to reduce [ferric ions

become ferrous ions] the solution that means the colour will just

disappear.

[Note: Avoid addition of SnCl₂ solution in excess.]

14. Then cool the solution.
15. Add 20ml of HgCl₂ and keep it for 5 minutes. Then add 10 c.c. of

titrating mixture.

16. Then titrate against standard K₂Cr₂O₇ solution using 2-3 drops of

Barium Di-Phenyl amine Sulphonate (BDS) solution.

17. Titrate until the violet colour comes.

 

%Fe₂O₃= Titre Value * Factor

            The procedure of Full analysis of  Gypsum sample is done

Chemicals Required: 1. Hydrochloric Acid: Concentrated, 1:1

2. Ammonium Chloride (Solid)
3. Ammonium Hydroxide (1:1)
4. Bromine Water (3.66% by weight)
5. Hydrogen Fluoride (Concentrated)
6. Buffer Solution (pH=10): 70gm of ammonium chloride in

• 570 ml  ammonium hydroxide and make upto 1 litre by
• distilled water.

7. Methyl Red: 0.1 gm of methyl red in 100ml of ethanol
8. Eriochrome Black-T: 100mg.of-eriochrome black–T

in10g.of sodium chloride.

9. Potassium permanganate (approx. 0.1N): Dissolve

about 3.2grams  KMnO₄ in water. Boil for 5 mins., filter,

cool, and standardize against sodium oxalate.

10.Ethylene Di amine Tetra Acetic Acid (EDTA): 3.7224

gm dissolve in 400 ml warm distilled water, cool it, add

600ml distilled water.

 

Procedure: 1. Weigh 0.5gm of gypsum sample  in a evaporating dish

2. Moist it with few drops of water and add 25-30ml of 1:1HCl in it.
3. Place evaporating dish on a wire gauge and evaporate to dryness on a hotplate until chloride smell  goes out.
4. Keep it for baking in oven for 1 hour (temperature 110-130 C) in oven.
5. Remove the evaporating dish, add about 30ml 1:1 HCl.
6. Slightly warm on the hot plate and filter it through Whatman no. 41 filter paper. Wash the residue 5-6 times with hot water.
7. Collect the residue 1 on the filter paper and the filtrate 1.

 

Residue 1: (For Silica)

8. Filter paper containing residue is transferred in a pre-weighed (C1)crucible, dried, ignited and ash at 900 – 1000⁰C in a furnace.
9. Bring out the crucible from the muffle furnace and keep it in a desiccator for 15 mins and then weigh the crucible (C2).

 

       SiO₂ (M)+ R₂O₃ = (W1)= (C2 – C1) 

   [Note: Some R₂O₃  remains with SiO₂]

10. Then moisten it by1-2 drops amount of water and add 1drop conc.

H₂SO₄ and then add 3-5ml of HF.

11. Heat it about to dryness until HF completely reacts with silica.

(When the fumes will stop that means reaction is over.)

12. Keep the crucible 2-3 minutes on furnace door and then keep it in

900 – 1000⁰C

muffle furnace for 15 mins.

13. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins. and then weigh the crucible (C3).

SiO₂ = (W2) =W1 – (C3 -C1)

 

Filtrate 1: (For Residual Oxide)  

2. To the filtrate 1 add about 5cc of saturated bromine water to it.
3. Allow it to boil till the excess bromine water is expelled off.

[Note: This operation is necessary to convert Fe⁺⁺ into Fe⁺⁺⁺ ions as

bromine water an oxidising agent. As compared to Fe⁺⁺ ions

Fe⁺⁺⁺ions’ hydroxide has a lower  solubility product]

4. After this 20ml of 10% NH₄Cl is added or 3-4gm of solid NH₄Cl is added.

[Note: NH₄Cl is used to prevent the ppt. of hydroxides of the

members of the subsequent groups by lowering the concentration

of OH ^– ions due to the common ion of NH ⁴⁺(i.e. common ions

effect)].

5. Add 2-3 drops of methyl red and then (1:1) NH₄OH solution drop by drop till the solution becomes yellow i.e. till complete precipitation of R₂O₃ group as hydroxide.
6. Then boil for a minute remove excess of ammonia.
7. Allow the precipitate to settle, and then filter it by Whatman no. 41 filter paper.
8. Give washings [5-6] of hot NH₄NO₃ and then 5-6 washings of cold distilled water.

             [Note: NH₄NO₃ wash is given to avoid colloidal formation in R₂O₃

precipitate to avoid complete drying of precipitate between

washings]

21. Collect the residue 2 on the filter paper and the filtrate 2.

 

Residue 2: (For R₂O₃)

22. Filter paper that containing residue is transferred in a crucible

which contain R₂O₃ of silica, dried and ignited it for 40 min. in a

900 – 1000⁰C muffle furnace.

23. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 minutes and then weigh the crucible (C4)

 

       SiO₂ + R₂O₃(M) = (W3) = ( C4 –C1)

 [Note: Some SiO₂ remains with R₂O₃]        

24. Then the material in the crucible is moisten by 1-2 drops of water

and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.

25. Heat it about to dryness until HF completely react with silica.

(When the fumes  will stop that means reaction is over.)

26. Keep the crucible 2-3 minutes on furnace door and then keep it in

900 – 1000⁰C  muffle furnace for 15 mins.

27. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C5).

Filtrate 2: (For CaO & MgO)

28. Take the filtrate 2 and make the solution acidic by few drops of

HCl and allow it to boil.

29. Then add to it drop by drop of NH₄OH till the red colour just disappears.
30. Then add 75ml of hot ammonium oxalate solution to it. This will give the precipitate of Calcium oxalate.
31. Boil it for 10minutes.
32. Filter through Whatman No.41 filter paper. Give washings of hot distilled water till it is free from Oxalate ions [Test with AgNO₃ solution].
33. Collect the residue 3 on the filter paper and the filtrate 3 in a 500ml volumetric flask and make it cool.

 

   Residue 4: (For Ca0)

34. Take 100cc of (1:1) H₂SO₄ and 150ml distilled water in the original beaker.
35. Heat it upto 80⁰c
36. Then transfer the filter paper in the beaker containing40.
37. Titrate against Std.KMnO₄ solution.

 

%CaO = Titre Value * Factor

 

Filtrate 4: (For MgO)

69. Make up the volume with water.

[Note: If the solution stays overnight then add slightly 1:1 HCl to

make it acidic.]

70. Take out 100ml of solution in a porcelain dish.
71. Add 3-5ml Tri-Ethanol Amine & 20 – 30ml Buffer solution.
72. Then the solution is stirred vigorously and then a pinch of Eriochrome Black-T indicator is added till the solution becomes light violet.
73. Titrate against Std. EDTA solution.

 

%MgO= Titre Value * 0.403 * Factor

 

 

 

Determination of Fe₂O₃

 

        Chemicals Required: 1.  Hydrochloric Acid (1:1)

2. Stannous Chloride: 50gm. Stannous chloride + 10ml HCl +

990ml distilled water + few pieces of metallic tin.

3. Mercuric Cloride:56 gm in 1litre of distilled water.
4. Titrating Mixture: 150ml H₂SO₄ + 150ml H₃PO₄ + 700ml

               distilled water

5. Barium Di-phenyl amino sulphonate:3gm in 100ml

distilled water.

6. Potassium Dichromate: Dissolve 4.9032 grams (dried at 150⁰ C) in water and dilute to one litre.

 

            Procedure:  1. Weigh and transfer 0.5gm of sample in a 250ml beaker                              

2. Wash the sides of the beaker with about 10-15 hot distilled water
3. Break the lumps of the sample with the glass rod.
4. Add 20ml of 1:1 HCl to it and add about 50ml of distilled water.
5. Allow it to boil for 4-5minutes on hot plate.
6. Then add drop by drop of SnCl₂ solution to reduce [ferric ions become ferrous ions] the solution that means the colour will just disappear.

[Note: Avoid addition of SnCl₂ solution in excess.]

7. Then cool the solution.
8. Add 20ml of HgCl₂ and keep it for 5 minutes. Then add 10 c.c. of titrating mixture.
9. Then titrate against standard K₂Cr₂O₇ solution using 2-3 drops of Barium Di-Phenyl amine Sulphonate (BDS) solution.
10. Titrate until the violet colour comes.

 

%Fe₂O₃= Titre Value * Factor

 

 

           The procedure of Full analysis of Slag sample is done

Chemicals Required: 1. Hydro chloric  Acid: Concentrated, 1:1

2. Ammonium Chloride (Solid)
3. Potassium Pyrosulphate (Solid)
4. Ammonium Hydroxide (1:1)
5. Bromine Water (3.66% by weight)
6. Sulfuric Acid: Concentrated, (1:1)
7. Hydrogen Floride (Concentrated)
8. Buffer Solution (pH=10): 70gm of ammonium chloride in

570 ml  ammonium hydroxide and make upto 1 litre by

distilled water 

9. Methyl Red: 0.1 gm of methyl red in 100ml of ethanol
10. Eriochrome Black-T: 100mg.of eriochrome black–T

in10g.of NaCl.

11. Potassium permanganate (approx. 0.1N): Dissolve

about 3.2grams KMnO₄ in water. Boil for 5 mins., filter,

cool, and standardize against sodium oxalate.

12. Ethylene Di amine Tetra Acetic Acid (EDTA): 3.7224

• gm dissolve in 400 ml warm distilled water, cool it, add
• 600ml distilled water.

 

Procedure:1. Weigh 0.5gm of slag sample  in a evaporating dish

2. Moist it with few drops of water and add 25-30ml of 1:1HCl in it.
3. Place evaporating dish on a wire gauge and evaporate to dryness on

• a hotplate until chloride smell  goes out.

4. Keep it for baking in oven for 1 hr. (temperature 110-130 C) in oven.
5. Remove the evaporating dish, add about 30ml 1:1 HCl.
6. Slightly warm on the hot plate and filter it through Whatman no. 41

• filter paper.

7. Wash the residue 5-6 times with hot water.
8. Collect the residue 1 on the filter paper and the filtrate 1.

 

Residue 1: (For Silica)

9. Filter paper containing residue is transferred in a pre-weighed

• (C1) crucible, dried, ignited and ash at 900 – 1000⁰C in a furnace.

10. Bring out the crucible from the muffle furnace and keep it in a

• desiccator for 15 mins and then weigh the crucible (C2).

       SiO₂ (M)+ R₂O₃ = (W1)= (C2 – C1) 

[Note: Some R₂O₃  remains with SiO₂]

3. Then the material in the crucible is moisten by 1-2 drops of water and add 1drop conc.H₂SO₄ and then add 3-5ml of HF.
4. Heat it about to dryness until HF completely reacts with silica.

(When the fumes  will stop that means reaction is over.)

5. Keep the crucible 2-3 minutes on furnace door and then keep it in 900 – 1000⁰C muffle furnace for 15 mins.
6. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C3).

 

SiO₂ = (W2) =W1 – (C3 -C1)

Filtrate 1: (For Residual Oxide)  

15. To the filtrate 1 add about 5cc of saturated bromine water to it.
16. Allow it to boil till the excess bromine water is expelled off.

[Note: This operation is necessary to convert Fe⁺⁺ into Fe⁺⁺⁺ ions as

bromine water an oxidising agent.  As compared to Fe⁺⁺ ions

Fe⁺⁺⁺ions’ hydroxide has a lower solubility product]

17. After this 20ml of 10% NH₄Cl is added or 3-4gm of solid NH₄Cl is

[Note: NH₄Cl is used to prevent the ppt. of hydroxides of the

members of the  subsequent groups by lowering the concentration

of OH ^– ions due to the common ion of NH ⁴⁺(i.e. common ions

effect)].

18. Add 2-3 drops of methyl red and then (1:1) NH₄OH solution drop by

• drop till the solution becomes yellow i.e. till complete precipitation
• of R₂O₃ group as hydroxide then boil for a minute remove excess of

19. Allow the precipitate to settle, and then filter it by Whatman no. 41

• filter paper.

20. Give washings [5-6] of hot NH₄NO₃ and then 5-6 washings of cold

• distilled water.

             [Note: NH₄NO₃ wash is given to avoid colloidal formation in R₂O₃

precipitate to avoid complete drying of precipitate between

washings]

21. Collect the residue 2 on the filter paper and the filtrate 2.

 

Residue 2: (For R₂O₃)

22. Filter paper containing residue is transferred in a crucible which c

• contain R₂O₃ of silica, dried, ignited it for 40 min. in a 900 – 1000⁰C
• muffle furnace.

23. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 mins and then weigh the crucible (C4)

 

       SiO₂ + R₂O₃(M) = (W3) = ( C4 –C1)

 [Note: Some SiO₂ remains with R₂O₃]

            To the material in the crucible add 3-5gm of potassium pyrosulphate

                          (K₂S₂O₇) and  then fuse it at low flame.

                     25. Keep the crucible to cool and extracted the fused material with hot

                          distilled water.

                     26. Keep on the hot plate till the material gets dissolved.

                     27. Take the extract solution in the evaporating dish and give washings

                           to the crucible.

                     28. Add about 20 ml of concentrated H₂SO₄ in the dish carefully.

                   29. Then keep the evaporating dish on the hot plate till white fumes

                         appears.

                     30. Then take out the evaporating out and filter through Whatman no. 41

                            filter paper.

                   31. Collect the filtrate in 200 ml volumetric flask.  Give sufficient washings

                         with hot distilled water.

                   32. Keep  the filtrate 3 for titanium estimation.

33. Ignite the residue in a previously weighed platinum crucible(C1) at

• 900-1000° C for 30-40 mins.

34. Bring out the crucible from the muffle furnace and keep it in a

• desiccator for 15 mins and then weigh the crucible (C5).

35. Then moisten it by1-2 drops amount of water and add 1drop conc.

H₂SO₄ and then add 3-5ml of HF.

36. Heat it about to dryness until HF completely react with silica. When

the fumes will stop that means reaction is over.

37. Keep the crucible 2-3 minutes on furnace door and then keep it in

900 – 1000⁰C muffle furnace for 15 minutes.

38. Bring out the crucible from the muffle furnace and keep it in a

desiccator for 15 minutes and then weigh the crucible (C6).

Filtrate 3: (Titanium)

39. Add 3ml Ortho Phosphoric Acid and then 5ml of H₂O_2. A Yellow colour

• solution will come.

40. Make up the volume by distilled water.
41. In UV Spectrometer, set Wave Length 410, Concentration 11.4.
42. First put the blank sample inside and align the mark.

[Note: Blank solution is prepared in same procedure only sample solution is not added here.]

43. Adjust the reading 0 with the blank sample solution
44. Then put the sample solution inside and take the reading.

 

% TiO₂= Reading * 0.04

 

    Filtrate 2: (For CaO & MgO)

45. Take the filtrate 2 and make the solution acidic by few drops of

HCl and  allow it to boil.

46. Then add to it drop by drop of NH₄OH till the red colour just

47. Then add 75ml of hot ammonium oxalate solution to it. This will

• give the precipitate of Calcium oxalate. And boil it for 10minutes.

48. Filter through Whatman No.41 filter paper. Give washings of hot

• distilled water till it is free from Oxalate ions [Test with AgNO₃
• solution].

49. Collect the residue 4 on the filter paper and the filtrate 4 in a

• 500ml volumetric flask and make it cool.

   Residue 3: (For Ca0)

50. Take 100cc of (1:1) H₂SO₄ and 150ml distilled water in the original

• beaker and heat it upto 80⁰c

51. Then transfer the filter paper in the beaker containing40.
52. Titrate against Std.KMnO₄ solution.

%CaO = Titre Value * Factor

    

   Filtrate 4: (For MgO)

53. Make up the volume with water.

[Note: If the solution stays overnight then add slightly 1:1 HCl to

make it acidic.]

54. Take out 100ml of solution in a porcelain dish.
55. Add 3-5ml Tri-Ethanol Amine & 20 – 30ml Buffer solution.
56. Then the solution is stirred vigorously and then a pinch of

• Eriochrome Black-T indicator is added till the solution becomes
• light violet.

57. Titrate against Std. EDTA solution.

 

%MgO= Titre Value * 0.403 * Factor

Determination of Fe₂O₃

 

           Chemicals Required: 1.  Hydrochloric Acid (1:1)

2. Stannous Chloride: Stannous chloride + 10ml HCl + 990ml distilled water + few pieces of metallic tin.
3. Mercuric Cloride:56 gm in 1litre of distilled water.
4. Titrating Mixture: 150ml H₂SO₄ + 150ml H₃PO₄ + 700ml distilled water
5. Barium Di-phenyl amino sulphonate:3gm in 100ml distilled water.
6. Potassium Dichromate: Dissolve 4.9032 grams (dried at 150⁰ C) in water and dilute to one litre.

 

            Procedure:  1. Weigh and transfer 0.5gm of slag sample in a conical flask or

                                    beaker of 250 ml.

2. Wash the sides of the beaker with about 10-15 hot distilled water
3. Break the lumps of the sample with the glass rod.
4. Add 20ml of 1:1 HCl to it and add about 50ml of distilled water.
5. Allow it to boil for 4-5minutes on hot plate.
6. Then add 2-3 drops SnCl₂ solution to reduce [ferric ions become ferrous ions] the solution.
7. Then cool the solution.
8. Add 20ml of HgCl₂ and keep it for 5 minutes. Then add 10 c.c. of titrating mixture.
9. Then titrate against standard K₂Cr₂O₇ solution using 2-3 drops of Barium Di-Phenyl amine Sulphonate (BDS) solution.
10. Titrate until the violet colour comes.

 

%Fe₂O₃= Titre Value * Factor

Determination of Fluorine By Specific Ion Analyzer

 

Preparation of Standard Solutions: 1. Hydrochloric Acid (1:1)

2. Acidified Alum Solution (0.8%): Transfer 8gm of alum AlKSO₄.12H₂O (AR Grade) to a one litre volumetric flask and add 800ml of 1:1 HCl. Make to 1000ml with distilled water. Store in a plastic bottle. This solutio is stable for idefinite time.
3. Sodium Citrate Solution (50% wt): Add 500gms of sodium citrate dehydrated crystals (Na₃C₆H₅O₇.2H₂O) A.R.Grade to 1000ml distilled water Mix until dissolved and a plastic bottle for good stability. This solution is stable for indefinite time.
4. Standard Fluorine Solution (0.1 M NaF): Dissolve 0.4199gms of A.R.Grade Sodium Fluoride (dried at 110⁰C) I distilled water and make up the volume to 100ml in a volumetric flask.

 

From 0.1M sodium Fluoride solution, prepare 10^-2M, 10^-3M and 10-4M fluoride solution and add equivalent amount alum solution in the above standards i.e. 5.0ml of 0.8% alum solutions per 100ml of standard fluorine solution.

 

Calibration:

 

• Take 10ml each of 10^-2M, 10^-3M and 10-4M sodium fluoride solution and add 10ml of sodium citrate solution in a beaker.
• Place the electrode in the mid range standard (i.e. 10^-2M). Set the function switch to mV absolute position. Note down the reading.
• Rinse the electrodes with distilled water, bloot dry with tissue paper and place in the most dilute standard (10^-4M NaF). Note down the stable reading.
• Rinse the electrodes with distilled water, dry it with tissue paper and record the stable reading for 10^-2M NaF solution.
• Using a semi logarithmic prepare a calibration curve by plotting the electrodes potential measured (mV-readings) on the linear axis and activity or concentration values of standards on the logarithmic axis.
• Use this calibration curve for the determination of unknown sample fluoride concentration.

Determination: 1. Weigh 0.5gm of dry, ground sample (-100 mesh) and transfer it

to a 250 ml beaker.

2. Add 10.0 ml of 0.8% alum solution and add about 50.0 ml of distilled water. Heat the solution on a hot plate. Boil it about 5mins. Cool to room temperature.
3. Filter the solution into 200 ml volumetric flask using Whatmann No.-41 filter paper. Wash it with distilled water. Dilute it with distilled water upto the mark and mix it well.
4. Pipette out 10ml of the above solution and 10ml of the sodium citrate solution into a clean dry 100 ml beaker. Cover it with a watch glass untill ready to measure the fluoride concentration of the solution.
5. Place the electrodes in the solution and note the stable mV reading. Determine the concetration of fluoride from the calibration graph.

 

% Fluoride in Sample = F ppm from calibration graph * 0.04

 

• For High purity sample preparation method is :

 

1. Take 0.1 gm sample in a 250ml beaker and add 100ml of alum solution.
2. Boil it for 5mins. Then digest it for 15 mins.
3. Filter it through WH No-41 in a 500ml volumetric flask.
4. Make up the volume. Then pipette out 25ml of it in a 100ml volumetric flask.
5. Make up the volume. Then again pipette out 10ml of solution from 100ml volumetric flask in the cup and add 10ml of sodium citrate solution.

 

• For Low purity sample preparation method is :

 

6. Take 0.1 gm sample in a 250ml beaker and add 100ml of alum solution.
7. Boil it for 5mins. Then digest it for 15 mins.
8. Filter it through WH No-41 in a 500ml volumetric flask.
9. Make up the volume. Then pipette out 25ml of it in a 100ml volumetric flask.
10. Make up the volume. Then again pipette out 10ml of solution from 100ml volumetric flask in the cup and add 10ml of sodium citrate solution.

Standard Solutions

 

• Hydrochloric Acid (1 N):

 

Take 300 ml concentrated HCl of specific gravity 1.16 to 2000ml and standard against sodium carbonate using methyl orange as the indicator.

 

• Hydrochloric Acid (N/2):

 

Take 225 ml concentrated HCl of specific gravity 1.16 to 5litres with distilled water.

 

• Sulphuric Acid (1 N):

 

Measure 60ml of pure concentrated H₂SO₄ of specific gravity1.84 and slowly add to 1000ml of distilled water in a large flask. Cool it. Then transfer it to a winchester bottle and dilute to 2000ml. Standardize with sodium carbonate.

 

• Sodium Carbonate (1 N):

 

5.3gms of pure dry Na₂CO₃ is dissolved in distilled water and made upto 100ml.

• Sodium Hydroxide(0.1 N):

 

Dissolve 4gms of NaOH in water and make upto 1000ml with distiled water. Standardize it against 0.1N HCl.

 

• Sodium Hydroxide(N/4):

Dissolve 50gms of NaOH in water and make upto 5litres with distiled water.

Standardize it against N/2 HCl.

 

• Ammonium Thiocyanate (0.05 N):

 

Dissolve 1.95gms of Ammonium Thiocyanate in water and dilute to 500ml.  Standardize against 0.1N AgNO₃ using ferric Alum as indicator.

• Ferrous ammonium sulphate (0.1 N):

 

Dissolve 39.2 gms in 1litre of dilute H₂SO₄ (1:4). Standardize against 0.1 N K₂Cr₂O₇ using Barium Diphenylamine sulphonate as the indicator.

 

• Potassium Permanganate:

 

Dissolve 5.65 KMnO₄  in 1000ml of distilled water.

1000ml 1 N KMnO₄ = 31.6 gms KMnO₄ = 67.0 gms Na₂C₂O₄ = 28gms CaO.

5.65 gms KMnO₄ = 5.0 gms CaO

Dissolve 5.65 gms KMnO₄ in 1000ml of distilled water.

So, 0.005 gms CaO = 1 ml KMnO₄.

So, 0.28 gms CaO = 56 ml KMnO₄.

0.28 gms CaO = 0.67 gms Na₂C₂O₄ = 56 ml KMnO₄.

 

• Potassium Dichromate:

 

Dissolve 3.0074 gms of analar K₂Cr₂O₇ in water and make up to 1 litre.

1000ml 1 N K₂Cr₂O₇ = 49.03 K₂Cr₂O₇ = 392.1 gms Fe(NH₄)₂(SO₄)₂.6H₂O

So, 3.0074 gms K₂Cr₂O₇ = 5.0 gms Fe₂O₃

 

• EDTA:

 

Weigh accurately 3.7224gms of disodium salt of EDTA dried at 40⁰C. dissolve in 250 ml cold water and finally dilute to 1litre. Standardize against standard hard water.

1ml     = 1 mg CaCO₃

1ml of EDTA solution = 0.00056CaO

=0.00043 gms MgO.

 

BUFFERS

 

• Ammonium – Ammonium Chloride

 

Dissolve 60gms of NH₄Cl in 200 ml H₂O. Add 620ml of concentrated NH₄OH (specific gravity 0.88) and dilute with water to one liter (pH: 10 – 11). Store in a polythene bottle.

 

• Sodium Hydroxide(25%)

 

Dissolve 250gms of NaOH (AR Grade) in 1000ml of water. Store in a polythene bottle.

 

• Monochloroacetic Acid

 

Dissolve 9.45gms of monochloroacetic acid and add 2gms NaOH in 100ml of H₂O. The pH is adjusted to pH 3.0 + 0.1. Store in a polythene bottle.

BENCH REAGENTS

 

• Acetic Acid(6N)

Dilute 250ml of Ammonia with 250ml of distilled water.

• Aluminium (1.0 mg Al₂O₃/ml)

Wash the metal with dilute HCl to remove any oxide film then with water and finally with alcohol followed by either.

Weigh 0.5293 gms of aluminum metal (99.99% Al ) into a nickel beaker provided with a cover and dissolve in 50ml of NaOH solution(40gm/lit). Transfer the solution to a 1000ml beaker containing 15 ml of hydrochloric acid (d = 1.18) adding the rinsing from the nickel beaker. Cool, and dilute to one litre in a volumetric flask.

• Ammonia solution(1:1)

Dilute 250ml of Ammonia with 250ml of distilled water.

• Ammonium Oxalate(Saturated)

Dissolve 100gms of ammonium oxalate in 2500ml of water.

• Ammonium Molybdate
• Dissolve 250 gms of ammonium molybdate in hot water. Filter it. Make up volume to 1 litre.
• Dissolve 100gms of Molybdic Acid in a mixture of 144ml conc. NH₄OH and 271ml H₂ Cool to room temperature and add slowly with constant stirring, 489 of concentrated HNO₃ and 1148ml of water. Allow to stand for 24 hours. Filter portions of the solution before use in the analysis.
• Barium Chloride (10%)

Dissolve 100gms of ammonium oxalate in 2500ml of water

• Bromine Water (Saturated Solution)

Prepare A 3.66% bromine solution by weight.

• Calcium (0.05 N)

Dissolve 5.0045 gms of dried (150⁰C) CaCO₃ in a slight excess of

dilute HCl (1+4). Boil to expel CO₂. Cool and dilute to one litre.

1ml = 2.804 mg CaO.

• Chromium (1.0 mg Cr₂O₃/ml)

Dissolve 1.9354 gms K₂Cr₂O₇ dried at 150⁰C in water. Dilute to one litre.

• Di-Ammonium Hydrogen Phosphate (10%)

Weigh 100 gms of Di-ammonium hydrogen phosphate. Dissolve in

water and make up to 1 litre with distilled water.

 

 

• Iron (0.1 mg Fe₂O₃/ml)

Dissolve 0.4911 gms Fe (NH₄)₂(SO₄)₂.6H₂O in water add 10ml 1:1

H₂SO₄ plus 5ml H₂O₂. Boil to decompose excess of H₂O₂. Cool and

dilute to one litre.

• Magnesium ( 1.0 mg MgO/ml )

Wash the metal in dilute HCl to remove any oxide film, then with

water and finally with alcohol followed by either. Dissolve 0.6032 gms

of the metal in a slight excess of HCl (1 + 9), cool, dilute to one litre in

a volumetric flask and mix.

• Manganese ( 0.1 mg MnO/ml )

Dilute the calculated volume (70.5 ml) of standardized against

Na₂CO₃ using methyl orange as the indicator.

• Mercuric Chloride (5%)

Dissolve 125 gms analar grade mercuric chloride in 2500ml of water.

• Nitric acid(1N)

Add 63ml HNO₃ to 500ml. Cool and dilute to one litre. Standardize

against Na₂CO₃.

• Oxalic Acid (10%)

Dissolve 250gms of oxalic acid in water. Dilute to 2500ml.

• Phosphoric-Sulphuric Acid Mixture

Mix 150ml of H₂SO₄ and 150ml of H₃PO₄. Pour in 700ml of water.

• Phosphate (0.1 mg P₂O₅/ml)

Dissolve 0.1917 gms of potassium dihydrogen orthophosphate in

water and dilute to one litre. Store in a polythene bottle.

• Potassium Dichromate (0.1N)

Dissolve 4.9032 gms (died at 150⁰C) in water and dilute to one litre.

• Potassium Permanganate (approx 0.1N)

Dissolve about 3.2 gms KMnO₄ in water. Boil for 5mins. Filter.

Cool and standardize against sodium oxalate.

• Silica (0.5 mg SiO₂/ml)

Fuse 0.500 gm of pure silica in 5 gms of Na₂CO₃. Cool, dissolve in water. Dilute to one litre. Store in a polythene bottle.

• Sulphuric Acid (5N)

Dilute 300ml of sulphuric acid with1900ml of cold water.

INDICATOR

 

• Alizarine Red S (1gm/lit)

Dissolve 0.1gm Alizarine Red S in 100ml of water.

• Barium Diphenyl Sulphonate(3 gm/lit)

Dissolve 0.3gms of barium Diphenyl Sulphonate in 100ml of warm

water then cool it.

• Bromo Cresol Green (1gm/lit)

Dissolve 0.1gm in 100ml of absolute alcohol (use 3 drops).

• Ferric Alum (10%)

Dissolve 10gms of ferric alum in a boiling mixture of 20ml of HNO₃

(6N) and 80 ml of water.

• Methylene Blue (1gm/lit)

Dissolve 0.1gm of methylene blue in 100ml of H₂O.

• Methyl Red (1gm/lit.)

Dissolve 0.1gm of methyl red in 100ml of ethanol (95%).

• Patton & Reader Indicator

Grind 0.1gms of the indicator with 10 gm of NaCl or Na₂SO₄. Store in

an airtight polyethene bottle.

• Phenolphthalein (10 gms/lit)

Dissolve 1gm of Phenolphthalein in 100ml of ethanol.

• Stannous Chloride (5%)

20 gm of SnCl₂ in a mix of 300ml water and 25 ml of HCl. Boil until

the solution is clear and colourless. Keep the solution in a closely

stopper bottle containing metallic tin.

• Starch (10 gm/lit)

Mix 1gm of soluble starch into a thin paste with 20ml of H₂O. Pour

while stirring the paste 80ml of boiling water. Boil for 1 min. Cool it.

• Solochrome Black T

Grind 0.1 gm of the indicator with 10 gm of NaCl or Na₂SO₄. Store in

an airtight polythene bottle.

• Thymolphthalein (0.4 gms/lit)

Dissolve 0.2 gm of thymolphthalein in 300ml of alcohol and dilute

with water to 500ml.

STANDARDIZATION OF SOME SOLUTIONS

 

• Standardization Of H₂SO₄

Take 20 ml of Na₂CO₃ solution in a flask, add 25 ml H₂O and 2 drops

of methyl orange titrate against sulphuric acid. Suppose 19.85 ml

H₂SO₄ solution is required for neutralization of 20 ml of normal

Na₂CO₃. We have

or,  20 ml of normal Na₂CO₃ solution = 0.98 gm H₂SO₄.

Then 19.85 ml H₂SO₄ solution 0.98 gms H₂SO₄

Or, 1000 ml/ H₂SO₄ solution contains 49.730 gms.

Dilution of H₂SO₄ to true normal

1000ml of true no H₂SO₄ contains 49.00 gms of H₂SO₄.

But in above case 1000ml contains 49.730 gms.

So, 1000 * 49.730 /49 = 10007.6 ml of true normal acid

Thus 1000ml of solution requires mixing with 7.6 ml of distilled water to give a true normal solution.

• Standardization Of KMnO₄

Take 0.67 gms Na₂C₂O₄ and moisten with water and then add 60-70 ml H₂SO₄ and make up to 200 ml then boil it.  Then titrate against the KMnO_4.  Let the reading be ‘X’.

So, KmnO4 factor = 56/X

• Standardization Of K₂Cr₂O₇

Take 0.4910 gms of Fe(NH₄)₂(SO₄).6H₂O and 50-60 ml of water and 10 ml of concentrated HCL heat it and cool it and then 5-10 ml mercuric chloride and 5-10 ml of Acid mixture and 4 drops of BDS and titrate against K₂Cr₂O₇. Let the reading be ‘Y’.

K₂Cr₂O₇ factor = 20/’Y’

• Standardization Of N/2 HCl

Dissolve 0.53 gm of Na₂CO₃ in water and titrate against prepared HCl using methyl orange indicator.

Normality of HCl = 10/ Titre Value.

 

• Standardization Of N/4 NaOH

Take 10 ml of N/2 HCl of above and standardize it with N/4 NaOH with phenolphthalein as indicator.

 

V1N1=V2N2

V1 is the volume of HCl.

N1 is the normality of HCl.

V2 is the volume of NaOH used during titration.

N2 is the normality of NaOH, which is unknown.