Sodium metal, liquid alloy

Properties Soft, silvery solid or liquid. (1) 78% potassium, 22% sodium mp -11C, bp 784C, d 0.847 (100C) (2) 56% potassium, 44% sodium mp 19C, bp 825C, d 0.886 (100C). Must be kept away from air and moisture. The liquid forms come under the class name potassium (or sodium) metallic liquid alloy. 

Many liquid alloys, in particular, the alkali-group IV alloys, exhibit (Zintl) anion clustering and show strong effects of compound formation. A typical example of such Zintl systems are sodium-tin alloys. In the solid NaSn crystal the Zintl anions Sn appear [1]. An interesting question is the stability of these anions in the liquid. Furthermore, the electrical conductivity of these alloys shows a strong dependence on composition [2] For the limiting (sodium-rich or tin-rich) cases a metallic (small) conductivity appears, but for the nearly equimolar compositions a semi-metallic behavior - with a considerably smaller conductivity - is observed. 

Nickel and nickel-rich alloys must be considered as having generally poor resistance to molten metals. Eldred has made a systematic investigation of the attack of liquid metals on solid metals and alloys, and his results for nickel, and nickel-chromium and nickel-copper alloys, are summarised in Table 7.35. These are for tests at up to 500 C and apart from potassium and sodium all the low-melting-point metals investigated produced moderate to severe attack on the nickel-rich materials. Furthermore, the values for many of the combinations given in the table indicate a marked tendency to preferential intergranular attack. 

Because sodium, which is liquid between about 100°C and 881°C, has excellent properties as a heat-transfer medium, with a viscosity comparable with that of water and superior heat conductivity , much attention has been paid to liquid sodium corrosion testing of metal and alloys. Indeed, ASTM have issued a Standard Practice which can be used for determination... 

Test method for determining the susceptibility to intergranular corrosion of 5XXX series aluminium alloys by mass loss after exposure to nitric acid (NAMLT test) Practice for liquid sodium corrosion testing of metals and alloys... 

A few of the relations of the alkali metals with one another have been investigated. Potassium with about 30 per cent, of sodium forms an alloy which is liquid at ordinary temp., and which has the appearance of mercury. This becomes pasty at 8°, and solidifies at a lower temp. If the alloy contains 77 per " /o" S>"x cent, of potassium, it remains liquid even... 

Chemically the liquid NaK alloy, usually used as a dispersion and on an inert support, provides more reactive surface area than either potassium or sodium metal alone, thus enhancing the reducing reactivity and permitting reactions to proceed atlower (eg, —12° C) temperatures. NaK alloys are suitable for chemical reactions involving unstable intermediates such as carbanions and free radicals. 

The explosion of chloroform in contact with an alkali metal may be demonstrated by means of the apparatus illustrated in Figure 92. About 0.3 gram of sodium or of potassium or of the liquid alloy of the two is introduced into a thin-wall glass tube, or, better yet, is sealed up in a small glass bulb, 6 to 8 mm. in diameter, which has a capillaiy 15 to 20 mm. in length. The tube or bulb containing the alkali metal is placed in the bottom of a narrow test tube into which 1 or 2 cc. of chloroform has already been introduced, and the apparatus is then... 

The metals are employed in a variety of alloys. Lithium generally hardens and strengthens, but also causes embrittlement from 0.05 to 0.1% is used in Al, Zn and Mg alloys. Sodium is an important additive to lead such an alloy is the basis of the manufacture of lead tetraethyl, and another, containing 0.6% Na, 0.6% Ca and 0.05% Li, is a bearing metal. Ternary alloys of caesium with aluminium and either barium or strontium are used in photoelectric cells. Liquid sodium or sodium-potassium alloy is employed to transfer heat from the core of certain atomic reactors, e.g. Dounreay fast breeder. 

The results have been reported of a comparative study of the measured electrical resistivities of liquid alkali metals and alloys, and the theoretical predictions for this quantity obtained within the diffraction model.48 The composition dependence of the Knight shifts in Na-Cs, Na-Rb, K-Rb-Cs, and Na-Rb-Cs liquid alloys has also been examined.49 Addition of small quantities of rubidium (0.3—4.51 atom %) to liquid sodium increases the electrical resistivity almost linearly with increasing solute concentration. With increasing temperature from 100 to 1100 °C, the effect of rubidium on the resistivity of sodium progressively diminishes.50 Addition of the solutes Hg, Tl, and Pb increases the resistivity of liquid potassium linearly with both increasing concentration and temperature. The unit increases in resistivity/pfl cm (atom%) , are 8.80, 9.85, and 15.8 for Hg, Tl, and Pb,... 

Obtained in brittle lumps which can be stored in an airtight container. It reacts only slowly with air or water, yet dries ether as completely as sodium wjre. Residues of ether or other liquids still containing some active alloy can be destroyed safely by the addition of water, as the reaction never reaches the violence observed with pure sodium metal. 

EINECS 231-132-9 HSDB 687 Natrium Sodio Sodium Sodium (liquid alloy) Sodium-23 Sodium ion Sodium metal UN1428. Metallic element polymerization catalyst for synthetic rubber, laboratory reagent, coolant in nuclear reactors, heat transfer agent, manufacture of tetraethyl and tetramethyl lead, sodium peroxide, sodium hydride radioactive isotopes in tracer studies and medicine, mp = 98 bp = 892 SG = 0.9 reacts with H2O. Foseco (FS) Ltd Ociel Chem. Ltd... 

Fission of aryl ethers can also be effected by metallic sodium or potassium. For instance, diphenyl ether, which is one of the most resistant ethers, is decomposed by liquid potassium-sodium alloy at room temperature.38 Weber and Sowa have cleaved 4,4 -disubstituted diphenyl ethers into benzene and phenol derivatives by sodium in liquid ammonia.39 Diallyl ether is converted by sodium dust at 35° into allylsodium and sodium allyl oxide, which provides a suitable method for preparation of allylsodium.3 7a Anisole, phenetole, benzyl phenyl ether, and diphenyl ether give the phenols in 90% yield, without by-products, when boiled with sodium or potassium in pyridine.40... 

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