Sodium hydroxide solution, 1 molar

Cyanides Water samples to determine cyanide must be kept chilled and dark for transport. They should be alkalized with sodium hydroxide solution (1 molar) on site and adjusted to a pH of around 8. 

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. 

A more active product is obtained by the following slight modification of the above procedure. Dissolve the succinimide in a slight molar excess of sodium hydroxide solution and add the bromine dissolved in an equal volume of carbon tetrachloride rapidly and with vigorous stirring. A finely crystalline white product is obtained. Filter with suction and dry thoroughly the crude product can be used directly. It may be recrystallised from acetic acid. 

To a solution of 4.76 g of 1-(4 -methyl-6 -methoxy-2 -pyrimidinyl)-3-methyl-3-pyrazoline-5-one in 200 ml of ether was added an ether solution containing 6 molar equivalents of diazomethane and the reaction mixture was allowed to stand at room temperature for 20 hours. After distilling off the solvent, the residue was dissolved in 160 ml of water, made alkaline (pH 10) with sodium hydroxide solution and extracted three times with 140 ml of benzene. The extract was washed with a small amount of water, dried over sodium sulfate and evaporated to give a crystalline mass. Recrystallization from isopropylether gave 1-(4 -methyl-6 -methoxy-2 -pyrimidinyl)-3-methyl-5-methoxypyrazole (3.96 g, 84%) as colorless prisms, MP 90° to 92°C. 

Suppose that 200. mL of hydrogen chloride at 690. Torr and 20.°C is dissolved in 100. mL of water. The solution was titrated to the stoichiometric point with 15.7 mL of a sodium hydroxide solution. What is the molar concentration of the NaOH in solution ... 

An old bottle labeled Standardized 6.0 m NaOH was found at the back of a shelf in the stockroom. Over time, some of the NaOH had reacted with the glass and the solution was no longer 6.0 M. To determine its purity, 5.0 mL of the solution was diluted to 100. mL and titrated to the stoichiometric point with 11.8 mL of 2.05 M HCl(aq). What is the molarity of the sodium hydroxide solution in the bottle ... 

Sodium phenolate may be prepared in situ by evaporating molar equivalents of phenol and sodium hydroxide solution in the reaction flask on the steam bath under reduced pressure and drying the residue by heating the flask for several hours longer on the steam bath under reduced pressure. The solid cake of dry sodium phenolate breaks up in the succeeding step of the synthesis. 

Figure 10.41 Effect of temperature on degree of swelling of cotton fibres by sodium hydroxide (molar sodium hydroxide solution contains 40 g/l NaOH) [278]...

Photolysis of pentobarbitone (pentobarbital, 285) was achieved on a solution buffered to pH 11 with a low-pressure mercury lamp over 10 h. At this pH the mono anion was the main species present. The products identified were the dealkylated ethyl barbitone (286), the amide (294) and both diastereoisomers of the ureide (295). On more prolonged irradiation, there also appeared ethylhydroxybarbitone (287) and an unidentified dimeric compound. When ethylbarbitone (286) was photolysed in the same way, it gave (287) and 2-ethyl-2-hydroxymalonic acid. Finally, pentobarbitone was irradiated in molar sodium hydroxide solution, where the dianion would be the main form present, to give (295) with a small amount of (294) [175]. 

During the performance of a CIEF analysis, the capillary is first filled with the sample and ampholyte mixture. The focusing step begins with the immersion of the capillary in the anolyte (dilute phosphoric acid) and catholyte (dilute sodium hydroxide) solutions followed by application of high voltage. Typically, the catholyte solution is 20 to 40 mM NaOH, and the anolyte is half the catholyte molarity, e.g., 10 to 20 mM phosphoric acid. It is important that the catholyte be prepared fresh because sodium hydroxide solutions will gradually take up carbon dioxide from the atmosphere. 

Triiron tetroxide is obtained from its natural mineral magnetite. In the laboratory the compound may be prepared by adding sodium hydroxide solution to an aqueous solution of 1 2 molar mixture of ferrous and ferric salt. (i.e., 1 mol FeCL + 2 mol FeCls). The resulting black precipitate of the hydroxide on heating dehydrates to gives triiron tetroxide ... 

A reactor charged with 4,4 -diphenylether-dicarboxylic acid, hydrazinesulfate, and polyphosphoric acid were mixed and reacted for 1 hour at 160°C and then further heated to 180°C. This mixture was then treated with 4-aminobenzenesulfonic acid and heated for an additional 2 hours. The molar solubility ratio of polyphosphoric acid/hydrazinesulfate and the molar monomer ratio ofhydrazinesulfatc/4,4 -dipheny-lether-dicarboxylic acid were kept constant at 10 and 1.2, respectively. The mixture was further treated with sufficient 4-aminobenzenesulfonic acid so that the molar ratio of in situ formed polyhydrazide was maintained at 1 1. After heating was stopped, the mixture was poured into warm water containing 5 wt% sodium hydroxide solution and a dark blue fiber obtained. The fiber was washed in distilled water and then dried in a vacuum furnace for 48 hours at 100°C. The dried material had a nitrogen/carbon ratio of 0.174 and a sulfur/carbon ratio of 0.058. The product had an Mw of... 

What is the molarity of a sodium hydroxide solution if 34.26 mL reacts with 0.333 7 g of sulfamic acid ... 

The undoped catalyst was prepared from the monophasic crystallized Ni Alj alloy (ref. 7). The molybdenum and chromium promoted catalysts were prepared from alloys with the composition N -x x where M = Mo (0.05 x 0.4) and M = Or (x - 0.07 or 0.11) (ref. 8). The catalysts were then prepared as described previously (ref. 9), by leaching the crushed alloys in a 6N sodium hydroxide solution at boiling temperature. The catalysts were kept under a molar solution of NaOH. 

Preparation of Reaction Solutions. In general, the reaction solutions of the aromatic alcohols (syringyl alcohol, vanillyl alcohol, and a-methylvanillyl alcohol and their ethers were prepared by adding aromatic alcohol or ether (usually 2.5 X 10-4 mole) to the solvent (water or ethanol) in a 10-ml. volumetric flask. After the model compound was dissolved, the calculated amount of a sodium hydroxide solution was added to make the reaction solution 1 1 molar (model compound to alkali). The solution was then made up to the 10 ml. mark by adding solvent. These solutions were allowed to react at room temperature for given periods. 

It can be prepared from succinimide by dissolving the latter in a slight molar excess of chilled sodium hydroxide solution (of approximately 3 m strength) and adding rapidly with vigorous stirring one molar proportion of bromine dissolved in an equal volume of carbon tetrachloride (CAUTION). A finely crystalline white product is obtained which may be collected, washed with ice-cold water, dried and used directly or recrystallised as detailed above. 

A more detailed mass transfer study on the carbon dioxide absorption in sodium hydroxide solution was performed using a falling-film microreactor [319]. Experimental investigations were made at a liquid flow of 50ml/h, with three NaOH concentrations (0.1,1 and 2 M), at a fixed inlet molar ratio C02 NaOH of 0.4, and for a range of C02 concentration of 0.8-100%. A two-dimensional reactor model was developed, and the results are similar to the experimental data at low NaOH concentrations (0.1 and 1 M). The agreement is less pronounced for higher concentrations such as 2 M NaOH, which could be explained by either maldistribution of... 

Bis[l-carboxy-l-ethylthio] Tellurium2 0.75 g (5 mmol) of tellurium dioxide are dissolved in 5 ml of 2 molar aqueous sodium hydroxide solution and this solution is added dropwise to a stirred solution of 2.5 g (24 mmol) of 1-carboxy-l-ethanethiol in 10 ml of water. The resultant yellow aqueous mixture is extracted several times with diethyl ether, the extracts arc combined, diethyl ether is removed at 20°, and the oily residue is kept under nitrogen for 7 days to allow crystals to form. The crystals are collected, dissolved in diethyl ether, and reprecipitated with petroleum ether yield 1.3 g (76%) m.p. 114°. 

Sodium Butanetellurolatc1 7.4 g (20 mmol) of dibutyl ditcllurium are dissolved in a mixture of 50 ml of methanol and 50 ml of tetrahydrofuran and placed in a nitrogen-flushed, three-necked, 250 ml flask fitted with a reflux condenser, stirrer, and dropping funnel. The mixture is heated to reflux on a water bath and a solution of 1.2 g (10.03 mmol) of sodium borohydride in 30 ml of 1 molar aqueous sodium hydroxide solution is added until the solution becomes colorless. 

Copper Ethanetellurolate1 0.3t g (1 mmol) of diethyl ditellurium are dissolved in 50 ml of ethanol, 0.18 g (5 mmol) of sodium borohydride in 10 ml of 1 molar aqueous sodium hydroxide solution are added, and the mixture is stirred vigorously under nitrogen for 15 min. A solution of 0.20 g (2 mmol) ofcopper(I) chloride in 25 ml of ethanol is added, the mixture is filtered, the brown solid is washed with ethanol and diethyl ether, and dried under vacuum. 

I vdroxybenzenetellurinic Acid4 15 g of 4-hydroxyphenyltellurium trichloride are dissolved in 500 ml of 2 molar aqueous sodium hydroxide solution and the mixture is acidified with 2 normal sulfuric acid. The initially formed precipitate is redissolved by adding sulfuric acid, the solution is allowed to stand for 48 h, the crystalline material is collected, and recrystallized from glacial acetic acid. 

Benzenetellurinic Acid2 Benzenetellurinyl nitrate is dissolved in 1 molar aqueous sodium hydroxide solution, the resultant solution is neutralized with 1 molar aqueous hydrochloric acid, and filtered. The solid is washed with water and dried m.p. 211 . 

Diorgano Tellurium5 (Thiourea Dioxide Method) A mixture of 2 mmol of the diorgano tellurium dichloride and 10 ml of 2 molar aqueous sodium hydroxide solution is stirred for 15 min at 20°. Then, 0.432 g (4 mmol) thiourea dioxide and 10 m/ petroleum ether (30-60°) are added. The mixture is stirred at 20° until it becomes clear. The phases are separated. The aqueous phase is extracted three times with diethyl ether. The combined organic phases are dried with anhydrous magnesium sulfate, the dried mixture is filtered, and the solvent evaporated from the filtrate. The residue is placed on a silica-gel column. The product is eluted with petroleum ether. 

Bis[4-methoxyphenyl] tellurium oxide was reduced to bis[4-methoxyphenyl] tellurium by thiourea dioxide in a two-phase system consisting of 2 molar aqueous sodium hydroxide solution and petroleum ether (30-60°)2. 

Bis[4-hydroxy-3-methylphenyl] Tellurium Dihydroxide1 0.41 g (1 mmol) of bis[4-hydroxy-3-methylphenyl] tellurium dichloride are dissolved in water, the solution is stirred, and 20 ml (4 mmol) of 0.2 molar aqueous sodium hydroxide solution are slowly added. The mixture is then filtered, the solid is washed with water followed by acetone/water (1/4, v/v), and the product is dried over phosphorus pentoxide under vacuum yield 0.30 g (80%). Conversion to the oxide occurred upon heating at 100°. 

Ethoxyphcnyl Tetramethylene Telluronium Bromide1 A solution of 3.08 g (6.2 mmol) of bis[4-ethoxyphenyl] ditellurium in a mixture of 2.5 ml of benzene and 7.5 ml of ethanol is heated under reflux. 0.04 g (10 mmol) of sodium borohydride dissolved in 8.5 ml of 1 molar aqueous sodium hydroxide solution followed by 0.22 g (1 mmol) of 1,4-dibromobutane dissolved in 5 ml of benzene are added dropwise to the refluxing solution. The warm mixture is stirred for 30 min, filtered, the solid is washed with diethyl ether, and dried under vacuum yield 0.30 g (80%) m.p. 280° (from acetonitrile). 

Cyanothieno[3,2-6]tellurophene1 0.5 g (2.0 mmol) of 5-formylthieno 3.2-/j tellurophenc arc suspended in 5 ml of water and a solution of 0.3 g(2.7 mmol) of hydroxylamine O-sulfonic acid in 1 ml ofwater is added to the vigorously stirred suspension. The mixture is stirred for 20 min, then 1 ml of 2 normal aqueous sodium carbonate solution followed by 3 ml of 2 molar aqueous sodium hydroxide solution are added dropwise. The resultant mixture is extracted with chloroform, the extract is evaporated, and the residue is chromatographed on silica gel with benzene as the mobile phase yield 0.3 g (60%) m.p. 151-154". 

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