Sodium hydroxide molarity

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]...

Your teacher has asked you to prepare 1.00 liter of a 0. lOO-molar aqueous solution of sodium hydroxide (molar mass 40.0 g). You should weigh out... 

Determine the concentration of the solution when 4.00 grams of sodium hydroxide (molar mass 40.0g mol ) Is dissolved In 200cm of water. 

Reacting stoichiometric quantities of lead nitrate solution with mixed solution of sodium azide/sodium hydroxide (molar ratio 2 1) at 35 °C leads to pure 3Pb(N3)2 2PbO [63]. Varying molar ratio and acidity of the reaction mixture lead to 12 different types of basic LA. It was observed that only one type of basic LA forms, if mixture of sodium azide and sodium hydroxide is added to the soluticni of lead nitrate. The opposite way of reactants mixing leads to formation of mixture of basic azides. It indicates that in neutral or acidic reaction mixture only one type of compound forms while from basic medium mixture of azides emerge [62]. 

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. 

It IS possible to use only one molar equivalent of amine m these reactions if some other base such as sodium hydroxide is present m the reaction mixture to react with the hydro gen chloride or carboxylic acid that is formed This is a useful procedure m those cases m which the amine is a valuable one or is available only m small quantities... 

Hoffman Degradation. Polyacrylamide reacts with alkaline sodium hypochlorite [7681-52-9], NaOCl, or calcium hypochlorite [7778-54-3], Ca(OCl)2, to form a polymer with primary amine groups (58). Optimum conditions for the reaction include a slight molar excess of sodium hypochlorite, a large excess of sodium hydroxide, and low temperature (59). Cross-linking sometimes occurs if the polymer concentration is high. High temperatures can result in chain scission. 

Nucleophilic Substitution Route. Commercial synthesis of poly(arylethersulfone)s is accompHshed almost exclusively via the nucleophilic substitution polycondensation route. This synthesis route, discovered at Union Carbide in the early 1960s (3,4), involves reaction of the bisphenol of choice with 4,4 -dichlorodiphenylsulfone in a dipolar aprotic solvent in the presence of an alkaUbase. Examples of dipolar aprotic solvents include A/-methyl-2-pyrrohdinone (NMP), dimethyl acetamide (DMAc), sulfolane, and dimethyl sulfoxide (DMSO). Examples of suitable bases are sodium hydroxide, potassium hydroxide, and potassium carbonate. In the case of polysulfone (PSE) synthesis, the reaction is a two-step process in which the dialkah metal salt of bisphenol A (1) is first formed in situ from bisphenol A [80-05-7] by reaction with the base (eg, two molar equivalents of NaOH),... 

Anhydrous gaseous or Hquid hydrogen sulfide is practically nonacidic, but aqueous solutions are weakly acid. The for the first hydrogen is 9.1 X 10 at 18°C for the second, is 1.2 x 10 . Reaction of hydrogen sulfide with one molar equivalent of sodium hydroxide gives sodium hydrosulfide with two molar equivalents of sodium hydroxide, sodium sulfide forms. Hydrogen sulfide reacts with sodium carbonate to produce sodium hydrosulfide... 

The preparation of cyclohexylmagnesium bromide is described on p. 22. The solution may be standardized by titrating against 0.5 N hydrochloric acid, and exactly one mole equivalent is used in the preparation. Five cubic centimeters of cyclohexylmagnesium bromide solution is slowly added to 20 cc. of water, an excess of the standard acid is added, and the excess acid titrated with sodium hydroxide. If 85 g. (3.5 moles) of magnesium, one liter of dry ether, and 571 g. of cyclohexyl bromide (3.5 moles) are used, a solution results which is about 2 molar. 

Typical features of a plywood resole formulation are a formaldehyde-to-phenol molar ratio in the 2.0 1 to 2.5 1 range, programmed formaldehyde, an alkali content from 4 to 8 wt% (calculated as sodium hydroxide), and pan solids of 40-50%. Resins used for laminated veneer lumber (LVL) tend to be similar to plywood resins in composition and molecular weight, though they are often designed for high-end cure speed. 

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. 

A solution of 100 g (1.7 mols) of isopropylamine in 60 cc of water was stirred into a solution of 4-hydroxyphenoxypropylene oxide. After the exothermic reaction has subsided, the reaction mixture was heated for two hours at 60Thereafter, the aqueous ethanol was distilled off, and the solid residue was dissolved in aqueous hydrochloric acid comprising more than the theoretical stoichiometric molar equivalent of hydrochloric acid. The aqueous acid solution was extracted with ether and was then made alkaline with sodium hydroxide, whereby a solid crystalline precipitate was formed which was filtered off and dried over phosphorus pentoxide. The product was 1,1 -(4 -hvdroxvphenoxv)-2-hvdroxv-3-isopropylamino-pro-pane. Its hydrochloride had a melting point of 166°Cto 169°C. 

A disaccharide is added to a pyridine SO3 complex solution, which is prepared by reacting 5 to 6 times the molar amount of liquid SO3 as much as that of disaccharide with 5 to 10 times the amount of pyridine as that of the disaccharide at 0°C to 5°C, for sulfation at 50°C to 70°C for 3 to 7 hours. After the completion of sulfation, the greater part of pyridine Is removed by decantation. The obtained solution exhibits an acidity that is so strong that it is improper to apply the reaction with aluminum ion and, therefore, sodium hydroxide is added for neutralization. After the remaining pyridine is removed by concentration, 100 unit volumes of water per unit volume of the residue is added thereto. To the solution is then added aluminum ion solution mainly containing aluminum dihydroxychloride, the pH of which is 1.0 to 1.2, in such an amount that the aluminum ion Is present in an amount of 4 to 6 molar parts of the amount of disaccharide to provide a pH of 4 to 4.5. The mixture is reacted under stirring at room temperature and the formed disaccharide poly sulfate-aluminum compound is allowed to precipitate. After filtration, the residue is washed with water and dried. 

The molarity of a soluble solute can vary over a wide range. With sodium hydroxide, for example, we can prepare a 6 M solution, a 1M solution, a 0.1 M solution, and so on. The words concentrated and dilute are often used in a qualitative way to describe these solutions. We would describe a 6 M solution of NaOH as concentrated it contains a relatively large amount of solute per liter. A 0.1 M NaOH solution is dilute, at least in comparison to 1M or 6 M. 

Figure 14.6 shows how the pH changes as fifty milliliters of one molar acetic acid is titrated with one molar sodium hydroxide. Notice that—... 

From the results of the titration calculate the millimoles of calcium present in the water. It may be expressed, if desired, as the equivalent mineral acidity (EMA) in terms of mg CaC03 per litre of water (i.e. parts per million of CaC03). In general, if the titre is A mL of sodium hydroxide of molarity B for an aliquot volume of V mL, the EMA is given by (AB x 50 x 1000)/V... 

V is the volume of sodium hydroxide used, and M is the molarity of the sodium hydroxide. 

The SnAt reactions were first successfully used in the synthesis of high-molecular-weight poly(arylene etherjs by Johnson et al.4,5 This reaction represents a good example for poly(ether sulfonejs in general, either in laboratory -or industrial-scale preparations. In this procedure, the bisphenol A and sodium hydroxide with an exact mole ratio of 1 2 were dissolved into dimethyl sulfoxide (DMSO)-chlorobenzene. The bisphenol A was converted into disodium bisphenolate A, and water was removed by azeotropic distillation. After the formation of the anhydrous disodium bisphenolate A, an equal molar amount of 4,4,-dichlorodiphenyl sulfone (DCDPS) was added in chlorobenzene under anhydrous conditions and the temperature was increased to 160°C for over 1 h... 

J.9 You are asked to identify compound X, which was extracted from a plant seized by customs inspectors. You run a number of tests and collect the following data. Compound X is a white, crystalline solid. An aqueous solution of X turns litmus red and conducts electricity poorly, even when X is present at appreciable concentrations. When you add sodium hydroxide to the solution a reaction takes place. A solution of the products of the reaction conducts electricity well. An elemental analysis of X shows that the mass percentage composition of the compound is 26.68% C and 2.239% H, with the remainder being oxygen. A mass spectrum of X yields a molar mass of 90.0 g-moF. (a) Write the empirical formula of X. (b) Write... 

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 ... 

Xylan-based micro- and nanoparticles have been produced by simple coacervation (Garcia et al., 2001). In the study, sodium hydroxide and chloride acid or acetic acid were used as solvent and non-solvent, respectively. Also, xylan and surfactant concentrations and the molar ratio between sodium hydroxide and chloride acid were observed as parameters for the formation of micro- and nanoparticles by the simple coacervation technique (Garcia et al., 2001). Different xylan concentrations allowed the formation of micro- and nanoparticles. More precisely, microparticles were found for higher concentrations of xylan while nanopartides were produced for lower concentrations of the polymer solution. When the molar ratio between sodium hydroxide and chloride acid was greater than 1 1, the partides settled more rapidly at pH=7.0. Regarding the surfactant variations, an optimal concentration was found however, at higher ones a supernatant layer was observed after 30 days (Garda et al., 2001). 

Industrial wastewater often is contaminated with strong acids. Environmental regulations require that such wastewater be neutralized before it is returned to the environment. A 1.50x10" mL sample of wastewater was titrated with 0.1250 M sodium hydroxide, and 38.65 mL of the base was required to reach the stoichiometric point. What was the molarity of hydronium ions in this sample of wastewater ... 

GL 22] [R 1] [P 23] The mass transfer efficiency of the falling film micro reactor as a function of the carbon dioxide volume content was compared quantitatively (Figure 5.30) [5]. The molar ratio of carbon dioxide to sodium hydroxide was constant at 0.4 for all experiments, i.e. the liquid reactant was in slight excess. 

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