Sodium potassium carbonate

Buffers are necessary to adjust and maintain the pH. Buffering agents can be salts of a weak acid and a weak base. Examples are ammonium, potassium, sodium carbonates (caustic soda), bicarbonates, and hydrogen phosphates [1345]. Weak acids such as formic acid, fumaric acid, and sulfamic acid also are recommended. Common aqueous buffer ingredients are shown in Table 17-8. 

Potassium sodium carbonate, K2C03,Na2C03,12H20. — A double salt of this formula is a constituent of vegetable ashes. At 35° C. it decomposes in accordance with the equation... 

When testing for molybdenum in mixtures containing metal salts, it is best to boil the test material with sodium carbonate or to fuse it with potassium sodium carbonate, to form water-soluble alkali molybdate. If a mixture of acid-insoluble sulfides is being tested, the sulfur can be roasted off and the alkali molybdate then dissolved out by digesting with alkali hydroxide. 

Procedure. The finely pulverized sample is fused with potassium sodium carbonate. A drop of the melt is transferred to a black spot plate with the aid of a platinum wire. After solution in 3 drops of 5 iV hydrochloric acid, a drop of a saturated methyl alcohol solution of morin is added, and the solution made alkaline with 4 drops of 5 iST sodium hydroxide. A bright green fluorescence in ultraviolet light shows the presence of beryllium. 

Procedure. A tiny (pin head) sample is finely ground and fused with sodium carbonate or potassium sodium carbonate in a loop of a platinum wire in the blowpipe. On cooling, the melt plus hydrochloric acid is taken to dryness on a platinum crucible lid. The residue is moistened with a drop of the acid and diluted with a little water. The further procedure is described on page 499. 

Fusion of a manganese compound with sodium carbonate and potassium nitrate (on porcelain) gives a green manganate(VI) (p.. 86)... 

Required Cyclohexanone, 20 g. hydroxylamine hydrochloride, 17 g. anhydrous sodium carbonate, 13 g. concentrated sulphuric acid, 50 ml. 25% aqueous potassium hydroxide solution, approx. 200 ml. chloroform, 120 ml. 

Required Anhydrous sodium carbonate, 5 g. potassium permanganate, 10 g. benzyl chloride, 5 ml. sodium sulphite, ca. 20 g. 

This type of extraction depends upon the use of a reagent which reacts chemically with the compound to be extracted, and is generally employed either to remove small amounts of impurities in an organic compound or to separate the components of a mixture. Examples of such reagents include dilute (5 per cent.) aqueous sodium or potassium hydroxide solution, 5 or 10 per cent, sodium carbonate solution, saturated sodium bicarbonate solution (ca. 5 per cent.), dilute hydrochloric or sulphuric acid, and concentrated sulphuric acid. 

Oxidation of 10-undecynoic acid to sebacic acid. Dissolve 2 00 g. of the acid, m.p. 41-42°, in 50 ml. of water containing 0 -585 g. of pure anhydrous sodium carbonate. Saturate the solution with carbon dioxide and add O IN potassium permanganate solution (about 1500 ml.) slowly and with constant stirring until the pink colour remains for half an hour the addition occupies about 3 hours. Decolourise the solution with a httle sulphur dioxide and filter off the precipitated acid through a... 

Suspend in a round-bottomed flask 1 g. of the substance in 75-80 ml. of boihng water to which about 0 -5 g. of sodium carbonate crystals have been added, and introduce slowly 4 g. of finely-powdered potassium permanganate. Heat under reflux until the purple colour of the permanganate has disappeared (1-4 hours). Allow the mixture to cool and carefully acidify with dilute sulphuric acid. Heat the mixture under reflux for a further 30 minutes and then cool. Remove any excess of manganese dioxide by the addition of a little sodium bisulphite. Filter the precipitated acid and recrystallise it from a suitable solvent (e.g., benzene, alcohol, dilute alcohol or water). If the acid does not separate from the solution, extract it with ether, benzene or carbon tetrachloride. 

Dissolve 1 0 g. (or 10 ml.) of the amine and 1 0 g. of 2 4-dinitrochloro-benzene in 5-10 ml. of ethanol, add a slight excess of anhydrous potassium carbonate or of powdered fused sodium acetate, reflux the mixture on a water bath for 20-30 minutes, and then pour into water. Wash the precipitated solid with dilute sodium carbonate solution, followed by dilute hydrochloric acid. Recrystallise from ethanol, dilute alcohol or glacial acetic acid. 

Nantokite, see Copper(I) chloride Natron, see Sodium carbonate Naumannite, see Silver selenide Neutral verdigris, see Copper(H) acetate Nitre (niter), see Potassium nitrate Nitric oxide, see Nitrogen(II) oxide Nitrobarite, see Barium nitrate Nitromagnesite, see Magnesium nitrate 6-water Nitroprusside, see Sodium pentacyanonitrosylfer-rate(II) 2-water... 

Sal soda, see Sodium carbonate 10-water Saltpeter, see Potassium nitrate Scacchite, see Manganese chloride Scheelite, see Calcium tungstate(VI)(2—)... 

Benedict s quantitative reagent (sugar in urine) This solution contains 18 g copper sulfate, 100 g of anhydrous sodium carbonate, 200 g of potassium citrate, 125 g of potassium thiocyanate, and 0.25 g of potassium ferrocyanide per liter 1 mL of this solution = 0.002 g sugar. 

Potassium sodium alloy Air, carbon dioxide, carbon disulflde, halocarbons, metal oxides... 

Seaweeds. The eadiest successful manufacture of iodine started in 1817 using certain varieties of seaweeds. The seaweed was dried, burned, and the ash lixiviated to obtain iodine and potassium and sodium salts. The first process used was known as the kelp, or native, process. The name kelp, initially apphed to the ash of the seaweed, has been extended to include the seaweed itself. About 20 t of fresh seaweed was used to produce 5 t of air-dried product containing a mean of 0.38 wt % iodine in the form of iodides of alkah metals. The ash obtained after burning the dried seaweed contains about 1.5 wt % iodine. Chemical separation of the iodine was performed by lixiviation of the burned kelp, followed by soHd-Hquid separation and water evaporation. After separating sodium and potassium chloride, and sodium carbonate, the mother Hquor containing iodine as iodide was treated with sulfuric acid and manganese dioxide to oxidize the iodide to free iodine, which was sublimed and condensed in earthenware pipes (57). 

The oxidant preheater, positioned in the convective section and designed to preheat the oxygen-enriched air for the MHD combustor to 922 K, is located after the finishing superheat and reheat sections. Seed is removed from the stack gas by electrostatic precipitation before the gas is emitted to the atmosphere. The recovered seed is recycled by use of the formate process. Alkali carbonates ate separated from potassium sulfate before conversion of potassium sulfate to potassium formate. Sodium carbonate and potassium carbonate are further separated to avoid buildup of sodium in the system by recycling of seed. The slag and fly-ash removed from the HRSR system is assumed to contain 15—17% of potassium as K2O, dissolved in ash and not recoverable. 

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