Sodium Hydroxide, with Lime, from Dried

Chill the concentrated solution of the amine hydrochloride in ice-water, and then cautiously with stirring add an excess of 20% aqueous sodium hydroxide solution to liberate the amine. Pour the mixture into a separating-funnel, and rinse out the flask or basin with ether into the funnel. Extract the mixture twice with ether (2 X25 ml.). Dry the united ether extracts over flake or powdered sodium hydroxide, preferably overnight. Distil the dry filtered extract from an apparatus similar to that used for the oxime when the ether has been removed, distil the amine slowly under water-pump pressure, using a capillary tube having a soda-lime guard - tube to ensure that only dry air free from carbon dioxide passes through the liquid. Collect the amine, b.p. 59-61°/12 mm. at atmospheric pressure it has b.p. 163-164°. Yield, 18 g. 

Soap has been used for cleaning for thousands of years. Xo one knows who invented it — but the method for making it was passed down from father to son, from mother to daughter. The early soap makers first had to burn wood to get potash (K2COs—see page, 59) or dried seaweed to get soda ash (Na,CO ).This was treated with lime to make potassium or sodium hydroxide (KOH or XaOH — see page 45), and this, in turn, was boiled with fat to make soap. Very much the same method is used today — except that the j... 

To 10 ml. of a cold 15% solution of sodium hydroxide is added 0.5 g. of ethylenebisbiguanidesilver(III) sulfate and the mixture is thoroughly stirred. The resulting solid is washed several times by decantation, first with 8-ml. portions of cold water to which has been added 2 drops of 15% sodium hydroxide through a sintered-glass funnel until free from sulfate and then three times with 3-ml. portions of cold water. The product is dried over calcium chloride and lime. The yield is quantitative. Anal. Calcd. for [Agm(en-big H)2](0H)3-3H20 N, 31.75 Ag, 24.49. Found N, 31.95 Ag, 24.45. 

The alcohol is purified by shaking with aqueous potassium hydroxide and extracting with diethyl ether that has been freed from peroxides with silver nitrate and sodium hydroxide. After being washed, the extract is treated with saturated sodium hydrogen sulphide solution, filtered, washed and dried over potassium carbonate. After removal of the ether, the alcohol is distilled under reduced pressure and the middle fraction dried over lime that has been burned in an atmosphere of nitrogen. 

Recognizing the need for a more uniform, polysaccharide material for detailed constitutional studies, O Dwyer prepared two hemicellulose fractions from beechwood previously extracted with water and 0.2% sodium hydroxide. As in previous work, the hemicelluloses were extracted from beechwood sawdust with 4% aqueous sodium hydroxide. Pectic materials were precipitated with lime-water, and a fraction designated hemicellu-lose-A was obtained by acidifying the solution with acetic acid. To the filtrate, from hemicellulose-A, was added 95 % ethanol to precipitate hemi-cellulose-B. After further purification, both of these hemicelluloses were subjected to chemical study. Hemicellulose-A ([ccjn —107° in 1 % sodium hydroxide) was observed to be soluble in cold water when freshly prepared, but it was insoluble after being dried. The preparation did not reduce... 

Methane from Sodium Acetate.— Acetic acid, as we shall understand before we have proceeded far in our study, is a compound related to methane. When the sodium salt of this acid, i.e., sodium acetate, is heated it loses carbon dioxide, CO2, and methane is produced. In practice this heating is carried out in the presence of an alkali, e.g., calcium or sodium hydroxide, which absorbs the carbon dioxide, and in this way assists in the reaction. In order that we may not be troubled by the presence of water, dry materials are used, the sodium acetate being fused to obtain it free of water. When this dry sodium acetate is heated with a mixture of sodium and calcium hydroxides, known as soda-lime, a gas is produced which may be collected over water. The gas so made is methane and is identical with that found naturally as marsh gas and as a constituent of fire damp, natural gas, coal gas and petroleum. 

Strychnine is prepared from the seeds by grinding them to a paste with slaked lime and water. The paste is dried and mixed with a suitable organic solvent (formerly benzene was used, but now less harmful solvents are substituted, e.g. chloroform). The slaked lime makes the mixture alkaline and under these conditions the strychnine dissolves readily in organic (i.e. oily) but not water-based solvents. The particulate debris is then removed by filtration and the liquid shaken with dilute sulphuric acid. This neutralises the effects of the lime and when the organic solvent and acid layers separate (cf. oil and vinegar salad dressing) the strychnine is dissolved in the latter. The organic solvent is decanted from the strychnine solution which is rendered alkaline by the addition of either ammonia or sodium hydroxide. This drastically reduces the... 

Chlorinating a slurry of lime in a sodium hydroxide solution forms crystals of calcium hypochlorite dihydrate, which can be filtered and dried. The precipitation of basic compounds is avoided by incremental addition of the calcium hydroxide to the sodium hydroxide solution during chlorination. In a batch process, all of the sodium hydroxide and 10-80% of the calcium hydroxide are introduced into a stirred reactor. Chlorine is then added. When the chlorination is nearly complete, the remainder of the calcium hydroxide is added without interrupting the flow of chlorine. The solids are separated and dried to from CalOCOj. In a continuous process, the sodium hydroxide solution is fed into one end of a long tubular reactor, and the calcium hydroxide slurry and chlorine are separately injected at a number of sites along the length of a jacketed reactor. The calcium hypochlorite is removed from the end of the reactor and dried. When impurities in the lime interfere with the crystallization of calcium hypochlorite, potassium hydroxide is substituted for up to 25% of the sodium hydroxide. ... 

Intermediates may also be used to remove impurities from low-quality lime. Figure 24.10 shows the precipitation of dibasic calcium hypochlorite from mixing lime with recycled solutions of calcium hypochlorite and sodium chloride. The crystals are separated and purified by elutria-tion. Sodium hypochlorite is added and the mixture is chlorinated to make calcium hypochlorite dihydrate. This product is filtered and dried. ° For further purification, the dibasic calcium hypochlorite crystals may be reacted with chlorine or a solution of calcium hypochlorite to precipitate hemibasic calcium hypochlorite. These crystals are separated, mixed with water, and chlorinated. The resulting calcium hypochlorite dihydrate is separated and dried. Sodium hydroxide may be added before chlorination, or sodium hypochlorite may be mixed with the filter cake to convert calcium chloride to calcium hypochlorite. " ... 

The reaction mixture is then transferred to a 2-I. round-bottom flask with wide neck, and to this is added all at once 300 g. of cracked ice, and the mixture is rapidly agitated by a rotary motion until the decomposition is complete (Note 7). Sufficient 30 per cent sulfuric acid is added to dissolve the magnesium hydroxide, and the mixture is then steam-distilled until oil no longer collects on the surface of the distillate. The distillate, which amounts to 1500-2500 cc., is saturated with sodium chloride and the upper layer separated. The aqueous layer is extracted with two loo-cc. portions of ether and the ether extract added to the alcohol layer. The ether solution is dried over anhydrous potassium carbonate, filtered, and heated carefully on the steam cone until all the ether is distilled. The crude alcohol is warmed one-half hour with about 5 g. of freshly dehydrated lime (Note 8). After filtering again and washing the lime with a little ether, the ether is distilled and the alcohol is distilled in vacuo from a Claisen flask (Note g). The carbinol distils at 88-93 /18 mm. (practically all distilling at 91°). The yield is 70-74 g. (61-65 P r cent of the theoretical amount) (Note 10). 

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