Dilute ammonia solution

Standard Colour Dilute 2.0 ml of standard iron solution with 40 ml DW in a Nessler cylinder. Add 2 ml of a 20% w/v solution of iron-free citric acid and 0.1 ml of thioglycollic acid, mix, make alkaline with iron-free ammonia solution, dilute to 50 ml with DW and allow to stand for 5 minutes. 

Ammonium Heptamolybdate Solution Dissolve 100 g of ammonium heptamolybdate tetrahydrate [(NH4)5Mo7024 4H20] in 900 mL of water in a 1000-mL volumetric flask. Add 10 mL of 25% ammonia solution, dilute to volume with water, and mix. This solution is stable for 4 weeks when stored at ambient temperature and shielded from light. 

Ammonia buffer (pH9.5), 1169 Ammonia solution, dilute, 1169 Ammonia solution, strong, 1169 Ammoniacal Silver Nitrate (test), 129 Ammonium mandelate, 718 Ammonium polysulphide solution, 1169 Ammonium sulphide solution, 1169 Amobarbital, 353 Amobarbital sodium, 353 Amodiachin, 347 Amodiaquine, 347 Amodiaquine hydrochloride, 347 Amolanone, xvii Amopyroquine, xvii Amorphan Depot, 437 Amosyt, 549... 

Dilute ammonia solution Dilute hydrochloric acid Dilute phosphoric acid Dilute sulfuric acid Dimethyl-P-cyclodextrin Dioctyl phthalate Dipotassium edetate Docusate calcium Docusate potassium Dodecyl gallate... 

Place a sample solution in dilute HCl (pH 1-2, 10-15 ml), containing not more than 5 pg Al, in a small beaker and add 10 mg of ascorbic acid. After 5 min add -2 ml of CAS solution, and adjust the pH to 5.3 0.2 with dilute ammonia solution. Dilute to volume in a 25 ml standard flask, mix, and measure the absorbance of the solution at 620 nm vs. a reagent blank solution. 

Material Test tubes, sand paper iron nail, copper sulfate hydrate, diluted ammonia solution, diluted sodium hydroxide solution. 

Dilute an aliquot of a 0 1 N hydrochloric acid solution of morphine, containing not more than 1 mg of morphine, to 20 ml with 0 1 N hydrochloric acid in a 50-ml graduated flask, add 8 ml of freshly prepared, 1 per cent sodium nitrite solution and mix well. After exactly fifteen minutes add 12 ml of dilute ammonia solution, dilute to volume and remix. Measure the extinction at the absorption maximum at about 442 mfJL, using 4-cm cells, with, in the comparison cell, a solution prepared exactly as above but substituting 20 ml of 0-1N hydrochloric acid for the sample solution. Read the morphine content from a standard curve prepared by carrying out the procedure on suitable volumes of a standard solution of morphine in OdN hydrochloric acid, covering the range 0 to 1 mg of morphine. 

Prepared by stirring phthalimide with cold concentrated ammonia solution. Hydrolysed to phlhalic acid with dilute acids. Dehydration with ethanoic anhydride gives first n-cyano-benzamide and then phthalonitrile. 

Addition of silver nitrate to a solution of a chloride in dilute nitric acid gives a white precipitate of silver chloride, AgCl, soluble in ammonia solution. This test may be used for gravimetric or volumetric estimation of chloride the silver chloride can be filtered off, dried and weighed, or the chloride titrated with standard silver nitrate using potassium chromate(VI) or fluorescein as indicator. 

To determine which halogen is present, take 1-2 ml. of the filtrate from the sodium fusion, and add dilute sulphuric acid until just acid to litmus. Add about 1 ml. of benzene and then about 1 ml. of chlorine water and shake. A yellowish-brown colour in the benzene indicates bromine, and a violet colour iodine. If neither colour appears, the halogen is chlorine. The result may be confirmed by testing the solubility of the silver halide (free from cyanide) in dilute ammonia solution silver chloride is readily soluble, whereas the bromide dissolves with difficulty, and the iodide not at all. 

Since the silver salts of the carboxylic acids are usually soluble in dilute nitric acid, they must be prepared by treating an aqueous solution of a neutral salt of the acid (and not the free acid itself) with silver nitrate solution. It is not practicable to attempt to neutralise the acid with sodium or potassium hydroxide solution, because the least excess of alkali would subsequently cause the white silver salt to be contaminated with brown silver oxide. The general method used therefore to obtain a neutral solution j to dissolve the acid in a small excess of ammonia solution, and then to boil the solution until all free... 

Ammonium Hydroxide Solution, Dilute, i vol. of cone, ammonia d, o-88o) to 3 vols. of water. 

Add dilute ammonia solution dropwise to 1 ml. of 0- N silver nitrate solution until the precipitate which forms just redissolves, and then dilute with 3 ml. of water. 

Dissolve 3 g. of copper sulphate pentahydrate and 1 g. of sodium chloride in 12 ml. of hot water, and add a solution of 1 g. of sodium bisulphite in 10 ml. of 5 per cent, sodium hydroxide solution. Shake, cool under the tap, and wash the precipitated wlute cuprous chloride with water by decantation. Dissolve the cuprous chloride in a few ml. of concentrated ammonia solution and dilute with water to 10 ml. 

Do not heat the silver solution or allow it to stand even for a few hours, since explosive silver fulminate may be formed. The ammoniacal solution of silver nitrate is prepared by treating 3 ml. of 0-lN silver nitrate solution with very dilute ammonia solution dropwise until the precipitate which is first formed just redissolves. 

It is preferable to use Tollen s ammoniacal silver nitrate reagent, which is prepared as follows Dissolve 3 g. of silver nitrate in 30 ml. of water (solution A) and 3 g. of sodium hydroxide in 30 ml. of water (solution B). When the reagent is requir, mix equal volumes (say, 1 ml.) of solutions A and JB in a clean test-tube, and add dilute ammonia solution drop by drop until the silver oxide is just dissolved. Great care must be taken in the preparation and use of this reagent, which must not be heated. Only a small volume should be prepared just before use, any residue washed down the sink with a large quantity of water, and the test-tubes rinsed with dilute nitric acid. 

Amides. TVeat the acid chloride cautiously with about 20 parts of concentrated ammonia solution (sp. gr. 0 - 88) and warm for a few moments. If no solid separates on cooling, evaporate to dryness on a water bath. Recrystallise the crude amide from water or dilute alcohol. 

The following simple test distinguishes fructose from all other carbohydrates. Upon heating a little fructose with dilute cobalt chloride solution, cooling and treating with a little ammonia solution, a violet to purple colour is developed, - the colour gradually fades and must be observed immediately after the addition of the ammonia solution. Green cobalt hydroxide is formed with all other carbohydrates. 

Cellulose. This is insoluble in water, hot and cold. It dissolves in a solution of Schweitzer s reagent (precipitated cupric hydroxide is washed free from salts and then dissolved in concentrated ammonia solution), from which it is precipitated by the addition of dilute acids. Cellulose is not hydrolysed by dilute hydrochloric acid. 

The filtrates from the decomposition of the brucine salts with dilute hydrochloride acid should be carefully preserved. The brucine Is recovered by the addition of an excess of dilute ammonia solution (1 4) if the solution becomes turbid before all the ammonia solution is added, introduce a little alcohol until the solution becomes clear. After several hours in an open beaker, filter oft the brucine, wash it well with cold water and dry it in the air. 

Picrates, Many aromatic hydrocarbons (and other classes of organic compounds) form molecular compounds with picric acid, for example, naphthalene picrate CioHg.CgH2(N02)30H. Some picrates, e.g., anthracene picrate, are so unstable as to be decomposed by many, particularly hydroxylic, solvents they therefore cannot be easily recrystaUised. Their preparation may be accomplished in such non-hydroxylic solvents as chloroform, benzene or ether. The picrates of hydrocarbons can be readily separated into their constituents by warming with dilute ammonia solution and filtering (if the hydrocarbon is a solid) through a moist filter paper. The filtrate contains the picric acid as the ammonium salt, and the hydrocarbon is left on the filter paper. 

The experimental details for mono-M-propylanillne are as follows. Reflux a mixture of 230 g. of aniline and 123 g. of n-propyl bromide for 8-10 hours. Allow to cool, render the mixture alkafine, and add a solution of 150 g. of zinc chloride in 150 g. of water. Cool the mixture and stir after 12 hours, filter at the pump and drain well. Extract the thick paste several times with boiling light petroleum, b.p. 60-80° (it is best to use a Soxhlet apparatus), wash the combined extracts successively with water and dilute ammonia solution, and then dry over anhydrous potassium carbonate or anhydrous magnesium sulphate. Remove the solvent on a water bath, and distil the residue from a Claisen flask with fractionating side arm (well lagged). Collect the n-propyl-aniline at 218-220° the yield is 80 g. Treat the pasty solid zincichloride with an excess of. sodium hydroxide solution and steam distil 130 g. of pure aniline are recovered. 

Heat a mixture of 15 g. of p-nitroacetanilide and 75 ml. of 70 per cent, sulphuric acid (1) under a reflux water condenser for 20-30 minutes or until a test sample remains clear upon dilution with 2-3 times its volume of water. The p-nitroaniline is now present in the hquid as the sulphate. Pour the clear hot solution into 500 ml. of cold water and precipitate the p-nitroanihne by adding excess of 10 per cent, sodium hydroxide solution or of concentrated ammonia solution. When cold (cool the mixture in ice water, if necessary), filter the yellow crystalline precipitate at the pump, wash it well with water, and drain thoroughly. Recrystallise it from a mixture of equal volumes of rectified (or methylated) spirit and water or from hot water. Filter, wash and dry. The yield of p-nitroanihne, m.p, 148°, is 11 g. 

Dissolve 5 g. of finely-powdered diazoaminobenzene (Section IV,81) in 12-15 g. of aniline in a small flask and add 2-5 g. of finely-powdered aniline hydrochloride (1). Warm the mixture, with frequent shaking, on a water bath at 40-45° for 1 hour. Allow the reaction mixture to stand for 30 minutes. Then add 15 ml. of glacial acetic acid diluted with an equal volume of water stir or shake the mixture in order to remove the excess of anihne in the form of its soluble acetate. Allow the mixture to stand, with frequent shaking, for 15 minutes filter the amino-azobenzene at the pump, wash with a little water, and dry upon filter paper Recrystallise the crude p-amino-azobenzene (3-5 g. m.p. 120°) from 15-20 ml. of carbon tetrachloride to obtain the pure compound, m.p. 125°. Alternatively, the compound may be recrystaUised from dilute alcohol, to which a few drops of concentrated ammonia solution have been added. 

Dissolve 1 0 g. of the compound in 5 ml. of dry chloroform in a dry test-tuhe, cool to 0°, and add dropwise 5g. (2-8 ml.) of redistilled chloro-sulphonic acid. When the evolution of hydrogen chloride subsides, allow the reaction mixture to stand at room temperature for 20 minutes. Pour the contents of the test-tube cautiously on to 25 g. of crushed ice contained in a small beaker. Separate the chloroform layer and wash it with a httle cold water. Add the chloroform layer, with stirring, to 10 ml. of concentrated ammonia solution. After 10 minutes, evaporate the chloroform on a water bath, cool the residue and treat it with 5 ml. of 10 per cent, sodium hydroxide solution the sulphonamide dissolves as the sodium derivative, RO.CgH4.SO,NHNa. Filter the solution to remove any insoluble matter (sulphone, etc.), acidify the filtrate with dilute hydrochloric acid, and cool in ice water. Collect the sulphonamide and recrystallise it from dilute alcohol. 

Method 2. Place 48 g. (41 -5 ml.) of freshly-distilled furfural, 52 g. of dry malonic acid (1), and 24 ml. of dry pyridine (2) in a 500 ml. round-bottomed flask, fitted with a reflux condenser. Heat the flask on a boiling water bath for 2 hours, cool the reaction mixture and dilute with 50 ml. of water. Dissolve the acid by the addition of concentrated ammonia solution, filter the solution and wash the filter paper with a... 

Cool the flask in ice, acidify with 10 ml. of cold 1 1-hydro-chloric acid and distil under reduced pressure (water pump) until most of the alcohol is removed. Add water to the residue, extract several times with ether, wash the combined ethereal extracts with N ammonia solution until a test portion gives no precipitate upon acidification. Extract the combined alkahne solutions once with a fresh portion of ether, and add the aqueous solution to an excess of dilute hydrochloric acid the final mixture should still be acidic to Congo red. Collect the crystalhne half-ester by filtration at the pump, wash it with water and dry at 100°. The yield is 14-5 g., m.p. 122-125°. Recrystallise by dissolving in about 40 ml. of warm benzene and adding an equal volume of petroleum ether (b.p. 40- 60°) 13 -5 g. of the colourless half-ester, m.p. 125-126°, are obtained. 

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