Sodium and potassium

K and Na bases which have been advocated for particular purposes include NaN-(SiMe3)2, a readily soluble base which reacts normally with phosphonium salts to give salt-free solutions of phosphoranes Me3SiCH2K, which is particularly 

Sodium and potassium are extracted from solid samples by wet digestion or dry ashing followed by acid dissolution of residue, and are determined by flame AAS using an air—acetylene flame. Liquid samples are aspirated after dilution. 

Fruits and fruit products. Weigh 300 g of jelly, syrup, fresh or dried fruit or preserve into a 21 beaker, add ca. 800 ml of water and extract by gently boiling for 1 h, replacing water lost by evaporation. Filter into a 21 volumetric flask, cool, dilute to volume, and dilute again if necessary to bring the analyte concentration to a level suitable for FAAS. 

Beverages. For wine samples dilute with water by a factor of 50—200 dilute mineral water samples as required. Dilute liquors with 50% ethanol by a factor required to bring absorbance onto the spectrometer scale. Prepare standards in identical diluent. 

Aspirate solutions into an air—acetylene flame (fuel-lean for sodium measurement) and measure absorbances at 589.00 nm and 766.49 nm for sodium and potassium, respectively. Use less sensitive wavelengths of 330.24/330.30 nm and 404.41 nm for sodium and potassium, respectively, when more concentrated (by a factor of about 200) solutions are used. 

Selected references The procedure was adapted essentially from AOAC Official Methods of Analysis [7h, 7u], J. Assoc. Off. Anal. Chem. [9] and the Subcommittee on Procedures of the Chemistry Task Force of the (US) National Shellfish Sanitation Program [24]. Other pertinent references are 7r, 21, 34, 36, 37e, f, 41, 50, 51, 63c, 139, 154, 155,159,165,166, 168. 

Sodium and Potassium. - A few reports have appeared focussing particularly on organometallie derivatives of sodium and potassium. 

The alkylation of a-formamido ketone enolates is a useful entry into 

In dissolved forms, mostly simple cations Na and K occur. In more strongly mineralized waters, ion associates such as [NaSO ] , [NaC03], [NaHC03]°, [KS04], [KC03] and [KHC03]° can be expected to exist. 

Sodium and potassium are common constituents of natural waters, with sodium being more prevalent than potassium. The Na K ratio usually ranges from 10 1 to 25 1. In atmospheric waters, the ratio is reduced in favour of potassium to about 1.5 1-2 1. From the viewpoint of concentration of metals in waters, sodium usually occupies the 3rd position following calcium and magnesium. However, in highly mineralized natural waters sodium can prevail over both these metals. 

From the health point of view, sodium and potassium are relatively unimportant in waters. Since about 1960 the possibility of an adverse effect of a high sodium concentration has been studied as it can influence negatively the health of people suffering from heart disease [2]. Sodium hydrogen carbonate mineral waters are important for the treatment of gastric diseases and the diseases of the biliary tract. 

Potassium provides a natural radioactive background of waters because natural potassium contains 0.0118 % of the radioactive nuclide. The contents of sodium and potassium in waters for various industries is usually not significant. The exception is the requirement for water quality to be used for high pressure steam boilers, as under higher pressures insoluble sediments (incrustations) of the type Na.2 0.R2 03.xSi02.j/H20 can be formed. 

Sodium and potassium play an important role in the classification of the chemistry of natural waters and the checking of the results of chemical water analysis. Therefore, the determination of these alkali metals should become a common procedure within the framework of chemical analysis of water. 

Discovery Sodium salts have been known from time immemorial. Sodium metal was discovered and isolated in 1807 by Humphry Davy in London. 

Mean content in an adult human body Content in a man s body (weight 70 kg)  

Elemental sodium is a soft metal which can be cut with a knife. It reacts violently with water and it oxidizes immediately on exposure to air. Sodium salts impart a characteristic orange/yellow color to flames. The most important compound is sodium chloride, commonly known as salt . Other important compounds include sodium carbonate, known as washing soda, and sodium hydrogen carbonate (sodium bicarbonate), known as baking soda. Caustic soda is sodium hydroxide, also called soda lye. Sodium nitrate, known as Chile saltpeter, is used as a fertilizer. The element is also used as a cooling agent in special nuclear reactors (see Chapter 52 The Radioactive Elements). Sodium is a necessary constituent of plant and animal tissue and its ions have an important role in the conduction of messages in nerves. 

Density Molar volume Melting point Boiling point Specific heat c at 298 K 

Nuclide Type Abundance % Nuclear spin Magnetic moment p  

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CH3)2N]3P0. M.p. 4°C, b.p. 232"C, dielectric constant 30 at 25 C. Can be prepared from dimethylamine and phosphorus oxychloride. Used as an aprotic solvent, similar to liquid ammonia in solvent power but easier to handle. Solvent for organolithium compounds, Grignard reagents and the metals lithium, sodium and potassium (the latter metals give blue solutions). 

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

Among the metals, for example, sodium and potassium are similar to each other and form similar compounds. Copper and iron are also metals having similar chemical properties but these metals are clearly different from sodium and potassium—the latter being soft metals forming mainly colourless compounds, whilst copper and iron are hard metals and form mainly coloured compounds. 

The ability of living organisms to differentiate between the chemically similar sodium and potassium ions must depend upon some difference between these two ions in aqueous solution. Essentially, this difference is one of size of the hydrated ions, which in turn means a difference in the force of electrostatic (coulombic) attraction between the hydrated cation and a negatively-charged site in the cell membrane thus a site may be able to accept the smaller ion Na (aq) and reject the larger K (aq). This same mechanism of selectivity operates in other ion-selection processes, notably in ion-exchange resins. 

The alkali metal tetrahydridoborates are salts those of sodium and potassium are stable in aqueous solution, but yield hydrogen in the presence of a catalyst. They are excellent reducing agents, reducing for example ion(III) to iron(II). and silver ions to the metal their reducing power is used in organic chemistry, for example to reduce aldehydes to alcohols. They can undergo metathetic reactions to produce other borohydrides, for example... 

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... 

Other sources of hazard arise from the handling of such chemicals as concentrated acids, alkalis, metallic sodium and bromine, and in working with such extremely poisonous substances as sodium and potassium cyanides. The special precautions to be observed will be indicated, where necessary, in the experiments in which the substances are employed, and will also be supplied by the demonstrator. The exercise of obvious precautions and cautious handling will in most cases reduce the danger to almost negligible proportions. Thus, if concentrated sulphuric acid should be accidentally spilled, it should be immediately washed with a liberal quantity of water or of a solution of a mild alkali. 

No cresol is obtained if sodium hydroxide alone is used, presumably because the fused sodium hydroxide has no solvent action upon the sodium p-toluene-sulphonate. Potassium hydroxide alone gives excellent results, as do also mixtures of Sodium and potassium hydroxide containing not less than 28 per cent, of potassium hydroxide. The experimental details utilise the minimum amount of potassium hydroxide for the salce of economy. 

An alloy of sodium and potassium (NaK) is used as a heat-transfer medium. Many potassium salts are of utmost importance, including the hydroxide, nitrate, carbonate, chloride, chlorate, bromide, iodide, cyanide, sulfate, chromate, and dichromate. 

All compounds of chromium are colored the most important are the chromates of sodium and potassium and the dichromates and the potassium and ammonium chrome alums. The dichromates are used as oxidizing agents in quantitative analysis, also in tanning leather. 

Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali group and is the second most electropositive and alkaline element. It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere. 

Thirty isotopes are recognized. Only one stable isotope, 1271 is found in nature. The artificial radioisotope 1311, with a half-life of 8 days, has been used in treating the thyroid gland. The most common compounds are the iodides of sodium and potassium (KI) and the iodates (KIOs). Lack of iodine is the cause of goiter. 

Several methods are available for producing thorium metal it can be obtained by reducing thorium oxide with calcium, by electrolysis of anhydrous thorium chloride in a fused mixture of sodium and potassium chlorides, by calcium reduction of thorium tetrachloride mixed with... 

Solvent Effects on the Rate of Substitution by the S 2 Mechanism Polar solvents are required m typical bimolecular substitutions because ionic substances such as the sodium and potassium salts cited earlier m Table 8 1 are not sufficiently soluble m nonpolar solvents to give a high enough concentration of the nucleophile to allow the reaction to occur at a rapid rate Other than the requirement that the solvent be polar enough to dis solve ionic compounds however the effect of solvent polarity on the rate of 8 2 reactions IS small What is most important is whether or not the polar solvent is protic or aprotic Water (HOH) alcohols (ROH) and carboxylic acids (RCO2H) are classified as polar protic solvents they all have OH groups that allow them to form hydrogen bonds... 

Both reactants m the Williamson ether synthesis usually originate m alcohol pre cursors Sodium and potassium alkoxides are prepared by reaction of an alcohol with the appropriate metal and alkyl halides are most commonly made from alcohols by reaction with a hydrogen halide (Section 4 7) thionyl chloride (Section 4 13) or phosphorus tri bromide (Section 4 13) Alternatively alkyl p toluenesulfonates may be used m place of alkyl halides alkyl p toluenesulfonates are also prepared from alcohols as their imme diate precursors (Section 8 14)... 

Metal carboxylates are ionic and when the molecular weight isn t too high the sodium and potassium salts of carboxylic acids are soluble m water Carboxylic acids therefore may be extracted from ether solutions into aqueous sodium or potassium hydroxide... 

The formation of micelles and their properties are responsible for the cleansing action of soaps Water that contains sodium stearate removes grease by enclosing it m the hydrocarbon like interior of the micelles The grease is washed away with the water not because it dissolves m the water but because it dissolves m the micelles that are dis persed m the water Sodium stearate is an example of a soap sodium and potassium salts of other C12-C1S unbranched carboxylic acids possess similar properties... 

The preparation of fluoroaromatics by the reaction of KF with perhaloaromatics, primarily hexachloroben2ene, has received considerable attention. Two methods were developed and include either the use of an aprotic, polar solvent, such as /V-methy1pyrro1idinone (8), or no solvent (9). These methods plus findings that various fluoroaryl derivatives are effective fungicides (10) prompted development of a commercial process for the production of polyfluoroben2enes (11). The process uses a mixture of sodium and potassium fluorides or potassium fluoride alone in aprotic, polar solvents such as dimethyl sulfoxide or sulfolane. 

Benzoates. The sodium and potassium salts of ben2oic acid [65-85-0], C2H 02, ate most effective against yeast and mold. They ate used in beverages, fmit products, chemically leavened baked goods, and condiments. Owing to their inhibitory effect on yeast, they cannot be used in yeast-leavened products. Potassium ben2oate was developed for use in reduced-sodium products. Ben2oates ate permitted for use in foods up to a level of 0.1% (76). 

Sorbates. The sodium and potassium salts of sorbic acid [110-44-1], ate used as mold and yeast inhibitors in dairy products, chemically... 

Algin occurs in all members of the class Phaeophjceae, brown seaweed, as a stmctural component of the cell walls in the form of the insoluble mixed calcium, magnesium, sodium, and potassium salt of alginic acid. 

There ate many classes of anticonvulsant agent in use, many associated with side effect HabiUties of unknown etiology. Despite many years of clinical use, the mechanism of action of many anticonvulsant dmgs, with the exception of the BZs, remains unclear and may reflect multiple effects on different systems, the summation of which results in the anticonvulsant activity. The pharmacophore stmctures involved are diverse and as of this writing there is htde evidence for a common mechanism of action. Some consensus is evolving, however, in regard to effects on sodium and potassium channels (16) to reduce CNS excitation owing to convulsive episodes. 

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). 

Sodium and Potassium. Whereas sodium ion is the most abundant cation in the extracellular fluid, potassium ion is the most abundant in the intracellular fluid. Small amounts of K" are requited in the extracellular fluid to maintain normal muscle activity. Some sodium ion is also present in intracellular fluid (see Fig. 5). Common food sources rich in potassium may be found in Table 7. Those rich in sodium are Hsted in Table 8. 

Sodium and potassium ions are actively absorbed from the intestine. As a consequence of the electrical potential caused by transport of these ions, an equivalent quantity of Cf is absorbed. The resulting osmotic effect causes absorption of water (56). 

In the other market areas, lead naphthenates are used on a limited basis in extreme pressure additives for lubricating oils and greases. Sodium and potassium naphthenates are used in emulsiftable oils, where they have the advantage over fatty acid soaps of having improved disinfectant properties. Catalyst uses include cobalt naphthenate as a cross-linking catalyst in adhesives (52) and manganese naphthenate as an oxidation catalyst (35). Metal naphthenates are also being used in the hydroconversion of heavy petroleum fractions (53,54) and bitumens (55). 

Use of excess sodium drives the reaction, usually done under an argon or helium blanket, to completion. After cooling, the excess sodium is leached with alcohol and the sodium and potassium fluorides are extracted with water, leaving a mass of metal powder. The metal powder is leached with hydrochloric acid to remove iron contamination from the cmcible. 

Nitric acid reacts with all metals except gold, iridium, platinum, rhodium, tantalum, titanium, and certain alloys. It reacts violentiy with sodium and potassium to produce nitrogen. Most metals are converted iato nitrates arsenic, antimony, and tin form oxides. Chrome, iron, and aluminum readily dissolve ia dilute nitric acid but with concentrated acid form a metal oxide layer that passivates the metal, ie, prevents further reaction. 

Full advantage of the neutron production by plutonium requires a fast reactor, in which neutrons remain at high energy. Cooling is provided by a hquid metal such as molten sodium or NaK, an alloy of sodium and potassium. The need for pressurization is avoided, but special care is required to prevent leaks that might result in a fire. A commonly used terminology is Hquid-metal fast-breeder reactor (LMFBR). 

However, the peroxomonophosphate ion decomposes relatively rapidly ia aqueous solution. A mixture of peroxodiphosphoric and peroxomonophoshoric acids can be produced by treatiag a cold phosphoric acid solution with elemental fluorine (qv) (49). Peroxodiphosphoric acid is not produced commercially. Ammonium, lithium, sodium, potassium, mbidium, cesium, barium, 2iac, lead, and silver salts have all been reported. The crystal stmctures of the ammonium, lithium, sodium, and potassium compounds, which crysta11i2e with varyiag numbers of water molecules, have been determined (50). 

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