Ferric Ammonium Sulphate

Dissolve 100 g. of iron alum (ferric ammonium sulphate) in 300 ml. of water at 65°, Pour the solution, with stirring, into a solution of 25 g. of hydroquinone in 100 ml, of water contained in a 600 ml. beaker. The quinhydrone is precipitated in fine needles. Cool the mixture in ice, filter with suction, and wash three or four times with cold water. Dry in the air between filter paper. The yield of quinhydrone, m.p, 172°, is 15 g. It contains a trace of iron, but this has no influence upon the e.m.f, of the quinhydrone electrode provided that the washing of the crude material has been thorough. The quinhydrone should be stored in a tightly-Btoppered bottle. 

Nessler cylinder 1 pair Ferric ammonium sulphate 1.726 g Sulphuric acid (0. 1 N) 10.0 ml Iron-free citric acid (20% w/v) 2.0 ml Thioglycollic acid 0.1 ml Iron-free ammonia solution 20 ml. 

Standard Iron Solution Weigh accurately 0.1726 g of ferric ammonium sulphate and dissolve in 10 ml of 0.1 N sulphuric acid and sufficient water to produce 1 Litre. Each ml of this solution contains 0.02 mg ofFe. 

However, in actual practice the thiocyanate solution is always taken in the burette and is run directly into the silver nitrate solution in the flask that has been duly acidified with nitric acid. Ferric ammonium sulphate is the choicest indicator since the end point is visibly detected by a deep red colour (ferric thiocyanate) due to the interaction of Fe2+ ions with a trace of SCN ion. 

Materials Required 0.1 N Silver nitrate solution 25 ml nitric acid (16 N) 2 ml ferric ammonium sulphate (10% w/v in water) 2 ml 0.1 N ammonium thiocyanate solution. 

Procedure Pipette 25 ml of a standard 0.1 N AgN03 solution into a glass-stoppered flask (iodine-flask), dilute with 50 ml of DW, add to it 2 ml of nitric acid and 2 ml of ferric ammonium sulphate solution and titrate with ammonium solution to the first appearance of red-brown colour. Each ml of 0.1 N silver nitrate is equivalent to 0.007612 g of NH4SCN. 

Materials Required Ethionamide 0.3 g dilute sulphuric acid (10% w/w) 10 ml dilute ammonia solution (4.25 ml of strong ammonia solution in 100 ml of water) 0.1 N silver nitrate 50 ml dilute nitric acid (10.6 ml of nitric acid to 100 ml of water) 60 ml ferric ammonium sulphate solution (10% w/v in water) 5 ml and 0.1 N ammonium thiocyanate solution. 

Procedure Weigh accurately about 0.3 g of ethionamide in a flask and dissolve in 10 ml of dilute sulphuric acid. Add to it 100 ml of water, 20 ml of dilute ammonia solution and rapidly 50 ml of 0.1 N silver nitrate solution. Allow the resulting mixture to stand for a few minutes, filter and wash the filter paper with three successive quantities, each of 10 ml of DW. To the combined filtrate and washings, add 60 ml of dilute nitric acid, cool and titrate with 0.1 N ammonium thiocyanate employing 5 ml of ferric ammonium sulphate solution as an indicator. Each ml of 0.1 N silver nitrate is equivalent to 0.008312 g of C8H1QN2S. 

To an approximately 25% solution of nitroguanidine in cold water some drops of saturated ferric ammonium sulphate solution are added, then a 24% solution of NaOH. The filtered solution has a red colour resembling that of fuchsine. 

Ferric Ammonium Sulphate Ammonio-Ferric Alum) FeNH (S04)s + 12H20. Mol. Wt. 482.28. 

Ferrous Salt — Dissolve 1 gm. of ferric ammonium sulphate in 20 cc. of water, add 1 cc. of hydrochloric acid and 1 drop of a freshly prepared solution of potassium ferri-cyanide. Neither a green nor a blue color should develop. 

Zinc and Copper. — To a solution of 2 gm. of ferric ammonium sulphate in 50 cc. of water add 10 cc. of ammonia water and filter. The filtrate should be colorless. 

Other method was described by Wagner (1+6) for the analysis and detection of salicylic acid and derivatives including salicylamide. Development was effected by using color reactions, with ferric ammonium sulphate, ammoniacal silver nitrate solution, potassium nitrate, HC1 and 5% KOH through diazotization and coupling with, 2-naphthol and coupling with diazotized sulphanilic acid. 

Ferric sulphate, Fe2(SQ4)3, is readily obtained in the anhydrous condition by heating the nonahydrate to about 175° C.,5 or by heating ferrous or any of the ferric ammonium sulphates (see p. 162) for prolonged periods in the presence of ammonium sulphate. 

Dissolve a few crystals in 10 ml of ethanol and add 0.5 ml of a 0.2% solution of ferric ammonium sulphate in 0.5M sulphuric acid—green-blue. 

Colour Test Dissolve 5 mg in 5 ml of O.IM hydrochloric acid and add 3 mg of / -phenylenediamine dihydrochloride shake to dissolve and add 0.1 g of zinc powder. After mixing, allow to stand for 2 minutes and add 10 ml of ferric ammonium sulphate solution—a blue or violet-blue colour develops. 

Fast Blue B Solution a 1 % solution of fast blue B salt (diazotised o-dianisidme) It should be freshly prepared Ferric Ammonium Sulphate Solution a 10% solution of feme ammonium sulphate... 

Ferric ammonium sulphate solution, 1169 Ferric chloride solution, 1169 Ferric Chloride (test), 133 Ferric iron, test on stomach contents, 5 Ferricyanide test on stomach contents, 5 Ferrioxamine, 516... 

Ferric Ammonium Sulphate Ammonio-Ferric Alum)... 

Dosimeter device Acidified ferric ammonium sulphate or ceric sulphate solutions respond to irradiation by dose-related changes in theiroptical density Accurately measure radiation doses... 

Ferric ammonium sulphate FeNH4(S04)2 12H2O octahedral 1.71... 

Five grams of precursor are refluxed for 1 h in about 200 cm distilled water, cooled, filtered and made up to volume in a 250 cm standard flask. An indicator is prepared by dissolving 500 g of ferric ammonium sulphate crystals in 700 cm distilled water. Now take 200 cm of this concentrated solution, add 400 cm concentrated HNO3 and making up to 1 litre with distilled water. Take a 10 cm aliquot and add 1 cm ferric alum indicator, measure the optical density in a spectrophotometer at 510 pm against a blank of 10 cm distilled water and 1 cm ferric alum indicator. The ppm level of NaSCN can be determined from a calibration graph. 

Spray reagent 1 g ferric ammonium sulphate is dissolved in... 

Dissolve 1 g of salicylic acid in 60 ml of ethanol, adjust the volume to 100 ml with water dilute 10 ml of this solution to 1 litre as a standard, making 1 ml = 0-1 mg of acid. Dissolve 0-6 g of aspirin in a measuring cylinder in 9 ml of ethanol and dilute with water to 90 ml. Take two similar Nessler cylinders into one pour 60 ml of the solution, into the other the remaining 30 ml with 3 ml of ethanol and adjust to the volume of the first. There is thus a difference of 200 mg in the amount of aspirin in the two solutions. Add 1 ml of 1 per cent acid ferric ammonium sulphate solution to each, mix and match the colour by adding the standard salicylic acid solution from a burette. Each ml of standard is equivalent to 0-05 per cent of salicylic acid in the sample. 

Comparison cell solution 2 ml dehydrated ethanol, 5 ml 0-2 per cent ferric ammonium sulphate solution, 5 ml buffer solution all made up to 50 ml. 

Pipette a volume of sample containing 2 5 g (2,500,000 units) of streptomycin sulphate into a 100-ml graduated fiask and dilute to volume with water. Dilute a 5-ml aliquot of this solution to 500 ml with water in a graduated flask, then transfer a 5-ml aliquot of this final dilution to a test-tube and add exactly 1 ml of 2N sodium hydroxide. Mix and place the tube in a water-bath. Exactly three minutes after the addition of the alkali, remove the tube from the bath and cool under a cold-water tap for exactly three minutes. At the end of this time add, by pipette, 4 ml of a 1 per cent solution of ferric ammonium sulphate in 0 75 N sulphuric acid, shake and allow to stand. After exactly ten minutes, measure the extinction at 550 mju, using 2-cm cells with water in the comparison cell. Read the concentration of streptomycin in the final 5-ml aliquot prepared from the sample from a standard curve. 

IN ammonium thiocyanate using ferric ammonium sulphate indicator. 

To about 5 g of suppository, in a stoppered flask, add 40 ml of warm ethanol, melt the fat and shake well. Add 40 ml of O IN silver nitrate, followed by 10 ml of nitric acid and allow to stand for two hours, shaking occasionally and maintaining the temperature just to keep the fat melted. Titrate the excess of silver nitrate with 0 1 N potassium thiocyanate using solution of ferric ammonium sulphate as indicator. 1 ml 0 1 N = 0 01312 g of CHI3. 

Add a drop of thioglycollic acid to 10 ml of a solution containing the iron salt, then add 0 5 ml of strong ammonia solution and dilute to 50 ml. Compare the colour produced with standard solutions containing known amounts of iron treated in exactly the same manner. The B,P. standard iron solution is a convenient strength for colorimetric comparison and contains 0 173 g of ferric ammonium sulphate per litre (1 ml = 0-00002 g Fe). 

A method of assay, applicable to most medicinal dyestuffs, depends upon their reduction with titanous chloride. The procedure has to be modified in detail for dissolving the dyestuff and for some dyes the endpoint is not indicated by a sharp decolorisation and an excess of titrant must be added, the excess being back titrated with ferric ammonium sulphate. 

X Add 10 ml HCl, 50 ml O IN TiCU, boil ten minutes and titrate with 0-lN ferric ammonium sulphate, ammonium thiocyanate indicator. Repeat operation without sample. 

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