Potassium hydroxide solutions boiling point

Primary aromatic amides are crystaUine sohds with definite melting points. Upon boiling with 10-20 per cent, sodium or potassium hydroxide solution, they are hydrolysed with the evolution of ammonia (vapour turns red htmus paper blue and mercurous nitrate paper black) and the formation of the alkah metal salt of the acid ... 

Addition of aqueous potassium hydroxide solution to the organic solvent would be expected to provide ample water for reaction but would also decrease the boiling point of the system. The decrease in solvent efficiency of those systems that were aqueous by design might then be attributed to the decreased reaction temperature. To support or disprove this hypothesis, additional experiments were made to ascertain the solvent capability of the studied systems at the same temperature. 

B. Mix 25 g of sample with 50 g of a 15% alcoholic potassium hydroxide solution in an Erlenmeyer flask, and reflux for 1 h or until saponification is complete. Cool, add 150 mL of water, and mix. After complete solution of the soap, add 60 mL of 2 A sulfuric acid, and while stirring frequently, heat the mixture until the fatty acids separate cleanly as a transparent layer. Wash the fatty acids with boiling water until free from sulfate, collect them in a small beaker, and warm on a steam bath until the water has separated and the fatty acids are clear. Allow the acids to cool, pour off the water layer, then melt the acids, filter into a dry beaker, and dry at 105° for 20 min. The solidification point of the fatty acids so obtained is not below 54° (see Melting Range or Temperature, Appendix IIB). 

Triethylamine (bp 89°) is another commonly used tertiary amine and is considerably more basic than pyridine. Along with all other aliphatic amines, it may be dried by heating to reflux with and distilling from barium oxide. Secondary amines are common impurities in tertiaiy amines and may be removed by heating the amine with a small amount of acetic anhydride. If the amine has a boiling point considerably different from that of acetic anhydride (bp 140°), it may be distilled directly from the reaction mixture. Otherwise, the reaction mixture should be shaken with 20 per cent potassium hydroxide solution, dried over potassium hydroxide, and distilled from barium oxide. 

The substituted phthalimides can be cleaved by ca. 20% hydrochloric acid at the boiling point or in a sealed tube at higher temperatures in some cases Posner s method may be used, in which the phthalimide is cleaved by potassium hydroxide solution to the phthalamic acid, whose hydrolysis is completed by hydrochloric acid.445 The phthalimides are, however, more conveniently cleaved by short boiling with a stoichiometric amount of hydrazine hydrate in ethanol 446 this gives the desired amine and phthalazone the latter may be hydrolysed by hydrochloric acid. Carbonyl groups present in the Aralkyl group of a phthalimide may be protected as acetal from the hydrazine fission.447 Phenylhydrazine is also useful for cleavage of phthalimido carboxylic acids.448... 

Although the digestion temperature is somewhat below the boiling-point, about 20 1. of water are lost in the reaction and by evaporation. This is made up, together with an additional 100 1., before filtration at 70°C. The residue is reslurried with 100 1. of hot 5 per cent potassium hydroxide solution and filtered again at 70°C before finally discarding. This wash liquor is added to the main filtrate to give a total volume of about 2501. of potassium niobate/tantalate solution in excess alkali. 

Caustic Potash Solution — (I) Chemical Designations — Synonyms Potassium Hydroxide Solution Lye Otemical Formula KOH—H O (ii) Observable Characteristics — Physical State (as normally shipped) Liquid Cobr Colorless Odor None (iii) Physical and Chemical Properties — Physical State at 15 X and 1 atm. Liquid Molecular Weight Not pertinent Boiling Point at 1 atm. >266, > 130, >403 Freezing Point Not pertinent Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 1.45 - 1.50 at 20° C (liquid) Vapor (Gas) Density Not pertinent Ratio of Specific Heats of Vapor (Gas) Not pertinent Latent Heat... 

Weigh accurately into a 250-ml conical flask an amount of sample expected to contain from 0 08 to 0 09 g As. If (a) soluble in water, dissolve in 30 ml of water (b) insoluble in water, dissolve in 5 ml of N sodium hydroxide and 20 ml of water and add 5 ml of N sulphuric acid (c) containing chloride, dissolve in 50 ml of water. Place several glass beads in the flask and a small funnel in the neck, add 8 g of ammonium persulphate and boil briskly until colourless and for two minutes longer. (In the case of sodium cacodylate heat for about five minutes after ebullition commences.) Add cautiously 50 ml of approximately N oxalic acid and boil vigorously for five minutes. Add cautiously 40 ml of dilute sulphuric acid and 10 ml of potassium iodide solution. Boil vigorously until the volume is reduced to about 40 ml. Cool, just remove the pale yellow colour by the addition of approximately 01N sodium sulphite drop by drop (1 to 3 drops usually) and immediately add about 60 ml of water. Add 1 drop of phenolphthalein solution and sufficient sodium hydroxide test solution to render just alkaline. Add 10 ml of dilute sulphuric acid, mix, cool, neutralise with sodium bicarbonate, add up to 5 g in excess and titrate with 0 1 N iodine. If starch solution is used add it just before the end-point is reached. 

To 0 3 g add 10 ml of ether and 10 ml of 0 5N ethanolic potassium hydroxide and boil under a reflux condenser for one and a half hours, shaking well during the first fifteen minutes. Evaporate the solvents, add 30 ml of water and warm to melt the waxy matter. Add 10 ml of 10 per cent barium chloride solution, mix well, heat to boiling-point, cool and filter. Add a further 10 ml of the barium chloride solution to the residue and again mix well, heat to boiling-point, cool and filter repeat the operation with a third 10-ml quantity of the barium chloride solution. Combine the filtrates, add 10 ml of dilute hydrochloric acid and extract with four or more successive quantities, each of 40 ml, of ether until extraction is complete. 

Alkaline corrosion. Zirconium is resistant to corrosion by almost all alkalies, both in solution and in the fiised condition, up to the boiling point. It resists sodium and potassium hydroxide solutions even under anhydrous conditions and resists molten potassium hydroxide and molten sodium hydroxide, the latter at temperatures greater than lOOO C. It resists calcium and ammonium hydroxides at concentrations up to 28% up to boiling. Because it is resistant to both alkalies and acids, it is the preferred material of construction for processes that cycle between acid and alkaline solutions. 

Electrolytes in low-temperature fuel cells are mainly strong acids such as sulfuric acid or phosphoric acid solutions, or strong alkali such as sodium or potassium hydroxide solutions. The migrating species are H" or OH". Concentrated solutions allow operating temperatures above the boiling point of water. Phosphoric acid solutions have been used up to 250 °C, potassium hydroxide solutions up to 300 °C. Special... 

Carbonyl Nitric Oxides. Another group of metal-carbonyl complexes, worthy of investigation as CVD precursors, consists of the carbonyl nitric oxides. In these complexes, one (or more) CO group is replaced by NO. An example is cobalt nitrosyl tricarbonyl, CoNO(CO)3, which is a preferred precursor for the CVD of cobalt. It is a liquid with a boiling point of 78.6°C which decomposes at 66°C. It is prepared by passing NO through an aqueous solution of cobalt nitrate and potassium cyanide and potassium hydroxide. ... 

In a 500-cc. round-bottomed flask, 21 g. (0.1 mole) of benzil (Org. Syn. Coll. Vol. 1, 1941, 87) and 21 g. (0.1 mole) of dibenzyl ketone (Note 1) are dissolved in 150 cc. of hot alcohol. The flask is fitted with a reflux condenser, the temperature of the solution is raised nearly to the boiling point, and a solution of 3 g. of potassium hydroxide in 15 cc. of alcohol is added slowly in two portions through the condenser. When the frothing has subsided the mixture is refluxed for fifteen minutes and then cooled to 0°. The dark crystalline product is filtered with suction and washed with three 10-cc. portions of 95 per cent alcohol. The product melts at 218-220° and weighs 35-37 g. (91-96 per cent of the theoretical amount) (Note 2). 

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