Alkalies potassium hydroxide

This remarkable reaction occurs because alkalis (potassium hydroxide) convert benzoin partly into the di-enol form, i.e. into the potassium derivative of stilbenediol C6H5.COK COK.CgHg.1... 

EXPLOSION and FIRE CONCERNS flammable NFPA rating Health 2, Flammability 3, Reactivity 2 flashback along vapor trail may occur closed containers may rupture violently when heated incompatible with strong oxidizers and alkalies, potassium hydroxide, and copper combustion by-products may include hydrogen chloride and phosgene gas use dry chemical, foam, carbon dioxide, or flooding quantities of water for firefighting purposes. 

Potassium permanganate is obtained from manganese dioxide by oxidation in two stages. The first is carried out by fusion with alkali (potassium hydroxide) in the presence of air or another oxidizing agent and yields potassium manganate, K2Mn04. This is taken up in water and decomposed into potas-... 

Incompatibilities and Reactivities Strong oxidizers, strong alkalis, potassium hydroxide, copper [Note Usually contains inhibitors to prevent polymerization.]... 

Aluminium oxide is a white solid, insoluble in water, with a very high melting point. If heated above red heat, it becomes insoluble in acids and alkalis, and can only be brought into solution by first fusing it with sodium or potassium hydroxide when an aluminate is formed. 

When an aqueous solution of benzenediazonium chloride is added to a cold concentrated solution of potassium hydroxide, the unstable potassium diazo-tate, C(HjN NOK, is formed, and this when heated with alkali to 130° changes to the isomeric but far more stable potassium isodiazotate it is probable that these copipounds have the structures (A) and (B) respectively. 

Since the silver salts of the carboxylic acids are usually soluble in dilute nitric acid, they must be prepared by treating an aqueous solution of a neutral salt of the acid (and not the free acid itself) with silver nitrate solution. It is not practicable to attempt to neutralise the acid with sodium or potassium hydroxide solution, because the least excess of alkali would subsequently cause the white silver salt to be contaminated with brown silver oxide. The general method used therefore to obtain a neutral solution j to dissolve the acid in a small excess of ammonia solution, and then to boil the solution until all free... 

The molecular weight of many carboxylic acids which arc freely soluble in cold water (i.e., chiefly the aliphatic acids) can readily be obtained by titrating a known weight of the acids in aqueous solution with standard sodium or potassium hydroxide solution, using phenolphthalein as an indicator. To avoid the use of unduly large quantities of the acid, it is advisable to use Mj2 caustic alkali solution, and in order to obtain a sharp end>point, this alkali solution... 

Sodium and potassium hydroxides. The use of these efficient reagents is generally confined to the drying of amines (soda lime, barium oxide and quicklime may also be employed) potassium hydroxide is somewhat superior to the sodium compound. Much of the water may be first removed by shaking with a concentrated solution of the alkali hydroxide. They react with many organic compounds (e.g., acids, phenols, esters and amides) in the presence of water, and are also soluble in certain organic liquids so that their use as desiccants is very limited... 

Boil 2 g. of the ester with 30 ml. of 10 per cent, sodium or potassium hydroxide solution under reflux for at least 1 hour. If the alcohol formed is water (or alkali) soluble, the completion of the hydrolysis will be indicated by the disappearance of the ester layer. Distil ofiF the liquid through the same condenser and collect the first 3-5 ml. of distillate. If a distinct la3 er separates on standing (or upon saturation of half the distillate with potassium carbonate), remove this layer with a capillary dropper, dry it with a little anhydrous potassium carbonate or anhydrous calcium sulphate, and determine the b.p. by the SiwoloboflF method... 

It is frequently advisable in the routine examination of an ester, and before any derivatives are considered, to determine the saponification equivalent of the ester. In order to ensure that complete hydrolysis takes place in a comparatively short time, the quantitative saponi fication is conducted with a standardised alcoholic solution of caustic alkali—preferably potassium hydroxide since the potassium salts of organic acids are usuaUy more soluble than the sodium salts. A knowledge of the b.p. and the saponification equivalent of the unknown ester would provide the basis for a fairly accurate approximation of the size of the ester molecule. It must, however, be borne in mind that certain structures may effect the values of the equivalent thus aliphatic halo genated esters may consume alkali because of hydrolysis of part of the halogen during the determination, nitro esters may be reduced by the alkaline hydrolysis medium, etc. 

Cool the solution in ice while the alkali hydroxide is dissolving some ammonia gas is evolved. When the potassium hydroxide has dissolved, separate the amine, and dry it for 24 hours over sodium hydroxide pellets. Filter into a Claisen flask and distil. Collect the di-n-butylamine at 157-160°. The yield is 31 g. 

Method A. Cool a solution of the nitrate-free dichloride, prepared from or equivalent to 5 0 g. of palladium or platinum, in 50 ml. of water and 5 ml. of concentrated hydrochloric acid in a freezing mixture, and treat it with 50 ml. of formahn (40 per cent, formaldehyde) and 11 g. of the carrier (charcoal or asbestos). Stir the mixture mechanically and add a solution of 50 g. of potassium hydroxide in 50 ml. of water, keeping the temperature below 5°. When the addition is complete, raise the temperature to 60° for 15 minutes. Wash the catalyst thoroughly by decantation with water and finally with dilute acetic acid, collect on a suction filter, and wash with hot water until free from chloride or alkali. Dry at 100° and store in a desiccator. 

Diethylene glycol method. Place 0-5 g. of potassium hydroxide pellets, 3 ml. of diethylene glycol and 0 5 ml. of water in a 10 or 25 ml. distilling flask heat the mixture gently until the alkali has dissolved and cool. Add 1-2 g. of the ester and mix well. Fit the flask with a thermometer and a small water-cooled condenser in the usual way. Heat the flask over a small flame whilst shaking gently to mix the contents. When only one liquid phase, or one hquid phase and one solid phase, remains in the flask, heat the mixture more strongly so that the alcohol distils. Identify the alcohol in the distillate by the preparation of the 3 5 dinitrobenzoate (Section 111,27,2). 

Alkali AletalIodides. Potassium iodide [7681-11-0] KI, mol wt 166.02, mp 686°C, 76.45% I, forms colorless cubic crystals, which are soluble in water, ethanol, methanol, and acetone. KI is used in animal feeds, catalysts, photographic chemicals, for sanitation, and for radiation treatment of radiation poisoning resulting from nuclear accidents. Potassium iodide is prepared by reaction of potassium hydroxide and iodine, from HI and KHCO, or by electrolytic processes (107,108). The product is purified by crystallization from water (see also Feeds and feed additives Photography). 

Barium titanate thin films can be deposited on various substances by treating with an aqueous solution containing barium salts and an alkanolamine-modifted titanate such as TYZOR TE (151). In a similar fashion, reaction of a tetraalkyl titanate with an alkah metal hydroxide, such as potassium hydroxide, gives oxyalkoxide derivatives (KTi O(OR) ), which can be further processed to give alkali metal titanate powders, films, and fibers (152—155). The fibers can be used as adsorbents for radioactive metals such as cesium, strontium, and uranium (156). 

The catalysts most often described in the literature (209—211,252) are sodium or potassium hydroxide, methoxide, or ethoxide. The reported ratio of alkali metal hydroxides or metal alcoholates to that of poly(vinyl acetate) needed for conversion ranges from 0.2 to 4.0 wt % (211). Acid catalysts ate normally strong mineral acids such as sulfuric or hydrochloric acid (252—254). Acid-cataly2ed hydrolysis is much slower than that of the alkaline-cataly2ed hydrolysis, a fact that has limited the commercial use of these catalysts. 

Alkali Fusion. Tha alkaU fusion of castor oil using sodium or potassium hydroxide in the presence of catalysts to spHt the ricinoleate molecule, results in two different products depending on reaction conditions (37,38). At lower (180—200°C) reaction temperatures using one mole of alkah, methylhexyl ketone and 10-hydroxydecanoic acid are prepared. The 10-hydroxydecanoic acid is formed in good yield when either castor oil or methyl ricinoleate [141-24-2] is fused in the presence of a high boiling unhindered primary or secondary alcohol such as 1- or 2-octanol. An increase to two moles of alkali/mole ricinoleate and a temperature of 250—275°C produces capryl alcohol [123-96-6] CgH gO, and sebacic acid [111-20-6] C QH gO, (39—41). Sebacic acid is used in the manufacture of nylon-6,10. 

The oxaziridine ring itself is stable towards alkali there is, for instance, no substitutive ring opening by hydroxyl ions as in oxiranes. 2-r-Butyl-3-phenyloxaziridine (56) is not attacked by methoxide ion in methanol during 12 h at room temperature 3-isopropyl-2-r-octyloxaziridine does not react at room temperature with either solid potassium hydroxide or potassium methoxide solution (57JA5739). 

A solution of 130 g. (0.52 mole) of this ester in 400 cc. of ethyl alcohol is placed in a two-necked 2-I. flask, carrying a dropping funnel and a reflux condenser, and is heated to boiling. Then one-third of a solution (Note 2) of 78.5 g. (1.4 moles) of potassium hydroxide in 400 cc. of alcohol is added from the dropping funnel, and the alcoholic solution is boiled until it becomes clear. Then a second third of the alkali solution is added, and the reaction mixture is again boiled until any precipitate disappears. Finally, the last third of the alcoholic potassium hydroxide solution is added. The addition of the alkali requires about twenty minutes. The reaction mixture is then boiled for forty minutes longer. 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Alkali Ammonia Biocides Sodium hydroxide (caustic soda) Potassium hydroxide (caustic potash) Calcium oxide (lime) Calcium hydroxide Sodium, potassium and calcium carbonates Ammonia (q.v.)... 

The plienolic/asbestos laminates (used up to 200°C) have excellent resistance to most mineral and organic acids but are attacked by strong oxidizing agents such as nitric and concentrated sulfuric acids and strong alkalis such as sodium and potassium hydroxide. Tanks, scrubbers, columns, pumps, pipes, etc., are fabricated from plienolic/asbestos laminates. 

This with potassium hydroxide in methanol forms de-OiV-dimethylarmepavine, m.p. 86-7°, (B. HCl, m.p. 229-30°) of which the methiodide, m.p. 233-4°, on treatment with alkali decomposes into trimetHylamine and a -p-anisyl-/3-(3 4-dimethoxy- 6 - vinylphenyl) -ethylene, m.p. 79°. The latter is oxidised by permanganate in acetone to anisic and m-hemipinic acids. With ethyl sulphate and alkali, armepavine gives 0-ethylarmepavine, an oil, which permanganate oxidises to p-ethoxybenzoic acid. Armepavine is similarly oxidised to p-hydroxybenzoic acid and l-keto-6 7-dimethoxy-2-methyl-1 2 3 4-tetiahydrowoquinoline and is therefore 6 7-dimethoxy-l-p-hydroxybenzyI-2-methyI-l 2 3 4-tetrahydrowoquinoline, i.e., it is laudanosine (p. 187) with MeO. at C replaced by H and MeO at C changed to HO. ... 

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