Precipitate appearance

Reaction with alcoholic silver nitrate. To carry out the test, treat 2 ml. of a 2 per cent, solution of silver nitrate in alcohol with 1 or 2 drops (or 0 05 g.) of the compound. If no appreciable precipitate appears at the laboratory temperature, heat on a boiling water bath for several minutes. Some organic acids give insoluble silver salts, hence it is advisable to add 1 drop of dilute (5 per cent.) nitric acid at the conclusion of the test most silver salts of organic acids are soluble in nitric acid. 

Benzenesulphonyl chloride test. Proceed as in the benzoyl chloride test, but use 15-20 ml. of 5 per cent, sodium hydroxide solution. Examine the product when the odour of the sulphonyl chloride has disappeared. (If no reaction has occurred, the substance is probably a tertiary amine.) If a precipitate appears in the alkaline solution, dilute with about 10 ml. of water and shake if the precipitate does not dissolve, a secondary amine is indicated. If the solution is clear, acidify it cautioiosly to Congo red with dilute hydrochloric acid a precipitate is indicative of a primary amine. 

Direct Borohydride Reduction of Alcohols to Alkanes with Phosphonium Anhydride Activation N-Proovlbenzene. To a solution of 5.56 g (20 mmol) of triphenylphosphine oxide in 30mL of dry methylene chloride at CfC was added dropwise a solution of 1.57 mL (10 mmol) of triflic anhydride in 30mL of dry methylene chloride. After 15 min when the precipitate appeared, a solution of 1.36g (10 mmol) of 3-phenyl-1-propanol in 10 mL of dry methylene chloride was added and the precipitate vanished in 5 min. An amount of 1.5g (40 mmol) of sodium borohydride was added as a solid all at once and the slurry was stirred at room temperature for... 

Orthophosphate Hquid mixtures are ineffective as micronuttient carriers because of the formation of metal ammonium phosphates such as ZnNH PO. However, micronutrients are much more soluble in ammonium phosphate solutions in which a substantial proportion of the phosphoms is polyphosphate. The greater solubiHty results from the sequestering action of the polyphosphate. The amounts of Zn, Mn, Cu, and Fe soluble in base solution with 70% of its P as polyphosphate are 10 to 60 times their solubiHties in ammonium orthophosphate solution. When a mixture of several micronutrients is added to the same solution, the solubiHty of the individual metals is lowered significantly. In such mixtures the total micronuttient content should not exceed 3% and the storage time before precipitates appear may be much shorter than when only one micronuttient is present. 

Beryllium Carbonates. BeryUium carbonate tetrahydrate [60883-64-9] BeCO 4H2O, has been prepared by passing carbon dioxide through an aqueous suspension of beryUium hydroxide. It is unstable and is obtained only when the solution is under carbon dioxide pressure. BeryUium oxide carbonate [66104-25-4] is precipitated when sodium carbonate is added to a beryUium salt solution. Carbon dioxide is evolved. The precipitate appears to be a mixture of beryUium hydroxide and the normal carbonate, BeCO, and usuaUy contains two to five molecules of Be(OH)2 for each BeCO. ... 

If a precipitate appears in the filtrate, filtration is repeated until two layers can be clearly distinguished. 

Reaction.—A delicate test for ethyl alcohol is the lodofornt reaction. Pour a few drops of alcohol into a test-tube and add about 5 c.c of a solution of iodine in potassium iodide, and then dilute caustic soda solution until the iodine colour vanishes. Shake up and narm very gently to about 6o°. If no turbidity 01 precipitate appears at once, set the test-tube aside for a time. Yellow crystals of iodoform will ultimately deposit, which have a peculiar odoui, and a characteiistic star shape nhen viewed under the microscope. The same reaction is given with... 

C) Preparation of Dipotassium Salt of [2-Phenyl-2-(2-Amino-5-Chlorophenyl)-l-Azaviny ] Maionic Acid (4306 CB) 50 g of caustic potash are dissolved in 1,350 ml of 96% ethyl alcohol, and 82 g (0.25 mol) of compound 4347 CB are then added all at once at a temperature of about 70°C. The solid dissolves rapidly to form a yellow solution which then loses color while simultaneously an abundant colorless precipitate appears. 

A mixture of 750 grams of 1-methyl-3-benzoyl-4-hydroxy-4-phenylpiperidine and 2,500 cc of 48% hydrobromic acid is refluxed for about 20 minutes. It is then poured into 8 liters of water. An oily precipitate appears which on standing crystallizes. It is filtered and crystallized from about 3.5 liters of alcohol. 2-Methyl-9-phenyl-2,3-dihydro-1-pyridindene hydrobromide, MP 201°-203°C, is obtained. 

A suspension of NaOEt, prepared by adding EtOH (2 rnL) to a suspension of xylene-washed Na (0.77 g, 33.5 mmol) in anhyd Et20 (90 mL), was added to a solution of diethyl 4-(chloromethyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate (1 10 g, 33 mmol) in anhyd El20 (600 mL) whereupon afine precipitate appeared immediately. The mixture was stirred and heated under reflux for 18 h, then cooled, and the precipitate of NaCl was removed by filtration. The volume of the filtrate was reduced to 100 mL, and the filtrate was washed with cold H20, then dried (MgS04). The Et2C) was evaporated under reduced pressure to yield the crude product as a golden oil [yield 7.3 g (83%)] which was purified by distillation bp 142-145 C/0.1 Torr. 

Shortly after the addition is complete, a voluminous white precipitate appears, and the resulting slurry is stirred and maintained at — 50° to... 

In a second method, a 1 g sample of poly(tri-n-butyltin methacrylate/methyl methacrylate) was dissolved in 4 mL of chloroform. One mL of concentrated HC1 was added dropwise with shaking until no more precipitate appeared. The precipitate was removed and then shaken again with a clean batch of chloroform and HC1. 

AND white precipitation appears (AgCl) THEN Ag is detected ELSE no Ag+ is contained in the sample solution... 

The supply of sea salts and trace metals via precipitation appears to contribute to the elevated content of water-soluble forms of alkaline and earth-alkaline elements and trace metals in the uppermost soil layer. 

The reaction mixture was stirred at room temperature and the reaction monitored by TLC. After completion, the reaction was carefully quenched with water (10 mL). A white precipitate appeared. 

To this suspension was added a solution of HBr (0.6 M, O.llmL). The suspension was stirred for 30 minutes at room temperature. After 15 minutes a yellow precipitate appeared. 

The Me-CBS needs to be recently obtained and stored under argon if a precipitate appears it can be due to the decomposition of the complex which is air and moisture sensitive. 

The Schlenk tube was filled with [(COD)Rh(acac)] (3.1 g) and cycloocta-1,5-diene (1.30 g) which were dissolved in 15mL of dry tetrahydrofuran. To this orange mixture, the solution of HBF4.OEt2 in tetrahydrofuran (7.52 mL) was added. A brown precipitate appeared, giving a viscous solution, which was diluted with 40 mL additional tetrahydrofuran to allow the reaction to stir efficiently. 

Silver and chloride ions combine to form a precipitate of AgCl. To the third test tube, add AgN03(aq), one drop at a time, until no more precipitate appears. Record the colour of the solution as the chloride ions precipitate. 

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