Sodium hydroxide preparation

Sodium hydroxide. Prepare a solution of approximately 0.5M sodium hydroxide in methylcellosolve. This should be standardised by titration with potassium hydrogenphthalate using the mixed indicator given below. 

Procedure. Wdgh out accurately about 2.5g of finely powdered arsenic(III) oxide, transfer to a 500 mL beaker, and dissolve it in a concentrated solution of sodium hydroxide, prepared from 2g of iron-free sodium hydroxide and 20 mL of water. Dilute to about 200 mL, and neutralise the solution with 1M hydrochloric add, using a pH meter. When the solution is faintly add transfer the contents of the beaker quantitatively to a 500 mL graduated flask, add 2 g of pure sodium hydrogencarbonate, and, when all the salt has dissolved, dilute to the mark and shake well. 

Experiment.—Dissolve 0-4 g. of the acetic acid-desoxycholic acid compound, prepared as above, in 4 c.c. of 2A-sodium hydroxide. Prepare also from about 100 mg. of the fatty acids isolated, by boiling with a few cubic centimetres of dilute sodium hydroxide solution, a soap solution and cool it till it sets to a jelly. Add part of the solution of desoxycholic-acetic acid. The soap dissolves. 

Wear nitrile rubber gloves, eye protection, and laboratory coat. Avoid breathing dust. In the fume hood, dissolve the arsenic compound in acidified boiling water (for 1 g of arsenic compound, use 100 mL of water containing 6 drops of concentrated hydrochloric acid). Add a solution of thioacetamide (for each 1 g of arsenic salt, use 0.2 g of thioacetamide in 20 mL of water). Boil the mixture for 20 minutes and then basify with 2 M sodium hydroxide (prepared by dissolving 8 g of NaOH in 100 mL of water). Filter the precipitate, dry, and package for disposal in a secure landfill site. ... 

Small Quantities. Wear butyl rubber gloves, laboratory coat, and eye protection. Work in the fume hood. Add 72 mL of 2.5 M sodium hydroxide (prepared by carefully dissolving 7.2 g of NaOH in 72 mL of water) to a 100-mL, three-necked, round-bottom flask equipped with a stirrer, dropping funnel, and thermometer. Place 5 mL of propiolactone (4.4 g, 0.06 mol) in the dropping funnel, and add it dropwise to the stirred basic solution at such a rate that the temperature does not exceed 45°C. When addition is complete, continue stirring for 1 hour, and then neutralize the solution with dilute acid and wash into the drain.9... 

Prepare 100 mL of a 0.050 M solution of the waste acid from the 5.0 M solution obtained from Klein Chemicals. If your laboratory doesn t already have 0.050 M solutions of sulfuric acid and phosphoric acid, also prepare 100 mL of each of these from the stock solutions that you have. You will do the titration experiment three times, once with each of these three solutions. If your laboratory doesn t already have a 0.10 M solution of sodium hydroxide prepared, also prepare at least 250 mL of this solution. None of these need to be prepared with any great precision. 

Solution 71% O-H3PO4 (orthophosphoric add). Mix 5 vol. parts of commercial concentrated (85%) 0-H3PO4 with 1 vol. part of Dl water (deionized water) Preparation Mix 5 vol. parts of (85%) 0-H3PO4 with 1 vol. part glycerin DAB7 and 0.5 —1.0 g/L sodium alkylarylsulfonate (phenysulfonate) 12% NaOH (sodium- hydroxide). Preparation Dissolve 120 g NaOH in 1 L of Dl water 1 % acetic acid. Preparation Add 20 ml glacial acetic acid to 1 L of Dl water... 

It is prepared by the action of sodium hydroxide and sodium hypochlorite on phthalimide (Hofmann reaction). When heated with soda lime it gives aniline. 

Diethylamine, CH3CH2)2NH. B.p. 55-5°C. Forms a crystalline i hydrate. Prepared by the action of a boiling solution of sodium hydroxide on nitrosodielhylaniline. Forms crystalline compounds with many metallic chlorides. 

Colourless prisms m.p. 130 C. Manufactured by treating maleic anhydride with water. It is converted to the anhydride by heating at By prolonged heating at 150 "C or by heating with water under pressure at 200 C, it is converted to the isomeric (trans) fumaric acid. Reduced by hydrogen to succinic acid. Oxidized by alkaline solutions of potassium permanganate to mesotartaric acid. When heated with solutions of sodium hydroxide at 100 C, sodium( )-malate is formed. Used in the preparation of ( )-malic acid and in some polymer formulations. 

Dimeihylamine, C2H7N, (CH3)2NH. Colourless, inflammable liquid with an ammoniacal odour, mp -96" C, b.p. 7°C. Occurs naturally in herring brine. Prepared in the laboratory by treating nitrosodimetbyl-aniline with a hot solution of sodium hydroxide. Dimethylamine is largely used in the manufacture of other chemicals. These include the solvents dimethylacetamide and dimethyl-formamide, the rocket propellant unsym-metrical dimethylhydrazine, surface-active agents, herbicides, fungicides and rubber accelerators. 

It reduces to 4-aminodimethylaniline and gives dimethylamine with hot sodium hydroxide solution. It is prepared by the action of nitrous acid upon dimethylaniline at 0 C. 

C12H4CI4O2. A by-product in the preparation of 2,4,5-trichlorophenol from 1,2,4,5-tetrachlorobenzene, sodium hydroxide and ethylene glycol. Causes chloracne in humans. 

This can be extracted from impure phosphine prepared by the action of sodium hydroxide on phosphorus. Unlike hydrazine, it has no basic properties. It is a powerful reducing agent and burns spontaneously in air, this reaction explaining why impure phosphine containing traces of diphosphane ignites spontaneously in air. 

Place 0 5 ml. of acetone, 20 ml. of 10% aqueous potassium iodide solution and 8 ml. of 10% aqueous sodium hydroxide solution in a 50 ml. conical flask, and then add 20 ml. of a freshly prepared molar solution of sodium hypochlorite. Well mix the contents of the flask, when the yellow iodoform will begin to separate almost immediately allow the mixture to stand at room temperature for 10 minutes, and then filter at the pump, wash with cold w ater, and drain thoroughly. Yield of Crude material, 1 4 g. Recrystallise the crude iodoform from methylated spirit. For this purpose, place the crude material in a 50 ml. round-bottomed flask fitted with a reflux water-condenser, add a small quantity of methylated spirit, and heat to boiling on a water-bath then add more methylated spirit cautiously down the condenser until all the iodoform has dissolved. Filter the hot solution through a fluted filter-paper directly into a small beaker or conical flask, and then cool in ice-water. The iodoform rapidly crystallises. Filter at the pump, drain thoroughly and dry. 

Prepare a solution of 12 5 g. of hydroxylamine hydrochloride in 20 ml. of water contained in a too ml. conical flask. Dissolve 7 g. of powdered sodium hydroxide in 20 ml. of water, cool the solution in ice-water, and then add it to that of the hydroxylamine hydrochloride. Place a thermometer in the mixed solution, and chill the flask in ice-water until the temperature of the solution is between 5 and 10 . Now add 12 ml. (9 5 gO of dry acetone (preferably from a burette to ensure... 

Since aliphatic hydrocarbons (unlike aromatic hydrocarbons, p. 155) can be directly nitrated only under very special conditions, indirect methods are usually employed for the preparation of compounds such as nitroethane, CjHsNO. When ethyl iodide is heated with silver nitrite, two isomeric compounds are formed, and can be easily separated by fractional distillation. The first is the true ester, ethyl nitrite, C,HiONO, of b.p. 17° its identity is shown by the action of hot sodium hydroxide solution, which hydrolyses it, giving ethanol and... 

A -Bromosuccinimide (prepared by the action of bromine on succinimide at o in the presence of sodium hydroxide) is a valuable specific reagent for brominating olefines in the a-methylene position to the double bond without simultaneously adding bromine to this bond. For example, if A -bromosuccini-mide is represented by (C4H40t)NBr —... 

B) Preparation of the Cuprous Solution, Add 85 ml. of concentrated ammonia solution (d, o-o88) to a solution of 50 g. of crystalline copper sulphate in 200 ml. of water, and cool to 10 . Dissolve 14 5 g. of hydroxylamine hydrochloride (or 17-4 g. of the sulphate) in 50 ml. of water, cool to 10 , and add a solution of 9 g. of sodium hydroxide in 30 ml. of water. Without delay add this hydroxylamine solution with stirring to the copper solution, which will be immediately reduced, but will retain a blue colour. 

The recrystallisation of diazoaminobenzene has to be performed with care, as the substance is freely soluble in most liquids and tends moreover to decompose if its solution is not rapidly cooled. Place 2 g. of the crude, freshly prepared, well-drained material in a boiling-tube, add about 15-20 ml. of ethanol and 1-2 drops of 10% aqueous sodium hydroxide solution, and then heat rapidly until boiling if the solution should contain insoluble impurities, filter through a small fluted paper, and at once cool the filtrate in ice-water. The diazoaminobenzene should rapidly crystallise out from the cold and stirred solution filter the crystals rapidly at the pump whilst the solution is still cold, as... 

Dissolve 3-8 g. of sodium in 75 mi. of rectified spirit, using otherwise the same conditions as in the preparation of anisole. Then add 15 g. of phenol, and to the clear solution add 13 2 ml. (19-1 g., n mois.) of ethyl bromide. Continue precisely as in the preparation of anisole, shaking the ethereal extract with sodium hydroxide solution as before in order to eliminate any unchanged phenol. Finally collect the fraction boiling at 168-172°. Yield, 14 g. 

Dissolve log. of powdered toluene-p-sulphonamide in 6o ml. of 10% aqueous sodium hydroxide (2 5 mols.) diluted with 50 ml. of water to moderate the reaction. Then, using the same precautions as in the previous preparation, add 127 ml. (17 g., 2 3 mols.) of dimethyl sulphate and shake the mixture vigorously. The crystalline dimethylamide rapidly separates from the warm... 

This preparation illustrates the use of dimethyl sulphate to convert a primary amino group into the secondary monomethylamino group, without the methy-lation proceeding to the tertiary dimethylamino stage. The methylation of anthranilic acid is arrested at the monomethylamino stage by using i-i molecular equiN alents of sodium hydroxide and of dimethyl sulphate. The reactions can be considered as ... 

The cost of this preparation (particularly for large classes) can be appreciably reduced by using a solution of 20 g. of sodium hydroxide in 25 ml. of water, in place of the potassium hydroxide solution. In this case, however, the product on standing overnight forms a very hard mass, which should be dissolved in tcarm water. The yields of alcohol and acid are unchanged. 

To 2 ml. of a freshly prepared dilute aqueous solution of sodium nitroprusside, add 2 drops of ethyl malonate and shake then add 2-3 drops of 10% aqueous sodium hydroxide solution and shake again. A red coloration at once appears, but fades in a few minutes to pale brown,... 

Preparation of REAOENTS.t It is essential for this preparation that the zinc powder should be in an active condition. For this purpose, it is usually sufficient if a sample of ordinary technical zinc powder is vigorously shaken in a flask with pure ether, and then filtered off at the pump, washed once with ether, quickly drained and without delay transferred to a vacuum desiccator. If, however, an impure sample of zinc dust fails to respond to this treatment, it should be vigorously stirred in a beaker with 5% aqueous sodium hydroxide solution until an effervescence of hydrogen occurs, and then filtered at the pump, washed thoroughly with distilled water, and then rapidly with ethanol and ether, and dried as before in a vacuum desiccator. The ethyl bromoacetate (b.p. 159 ) and the benzaldehyde (b.p. 179 ) should be dried and distilled before use. 

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