Sodium electrical conductivity

The metallic salts of trifluoromethanesulfonic acid can be prepared by reaction of the acid with the corresponding hydroxide or carbonate or by reaction of sulfonyl fluoride with the corresponding hydroxide. The salts are hydroscopic but can be dehydrated at 100°C under vacuum. The sodium salt has a melting point of 248°C and decomposes at 425°C. The lithium salt of trifluoromethanesulfonic acid [33454-82-9] CF SO Li, commonly called lithium triflate, is used as a battery electrolyte in primary lithium batteries because solutions of it exhibit high electrical conductivity, and because of the compound s low toxicity and excellent chemical stabiUty. It melts at 423°C and decomposes at 430°C. It is quite soluble in polar organic solvents and water. Table 2 shows the electrical conductivities of lithium triflate in comparison with other lithium electrolytes which are much more toxic (24). 

Niobium is used as a substrate for platinum in impressed-current cathodic protection anodes because of its high anodic breakdown potential (100 V in seawater), good mechanical properties, good electrical conductivity, and the formation of an adherent passive oxide film when it is anodized. Other uses for niobium metal are in vacuum tubes, high pressure sodium vapor lamps, and in the manufacture of catalysts. 

Sodium [7440-23-5] Na, an alkali metal, is the second element of Group 1 (lA) of the Periodic Table, atomic wt 22.9898. The chemical symbol is derived from the Latin natrium. Commercial iaterest ia the metal derives from its high chemical reactivity, low melting poiat, high boiling poiat, good thermal and electrical conductivity, and high value ia use. 

In 1932 a class of complexes consisting of ethers, sodium, and polycycHc hydrocarbons was discovered (19). Sodium reacts with naphthalene in dimethyl ether as solvent to form a soluble, dark-green, reactive complex. The solution is electrically conductive. The reaction has been described as follows... 

Some polymers from styrene derivatives seem to meet specific market demands and to have the potential to become commercially significant materials. For example, monomeric chlorostyrene is useful in glass-reinforced polyester recipes because it polymerizes several times as fast as styrene (61). Poly(sodium styrenesulfonate) [9003-59-2] a versatile water-soluble polymer, is used in water-poUution control and as a general flocculant (see Water, INDUSTRIAL WATER TREATMENT FLOCCULATING AGENTs) (63,64). Poly(vinylhenzyl ammonium chloride) [70304-37-9] h.a.s been useful as an electroconductive resin (see Electrically conductive polya rs) (65). 

Ash is a measure of residual sodium acetate. A simple method consists of dissolving the PVA in water, diluting to a known concentration of about 0.5 wt %, and measuring the electrical conductivity of the solution at 30°C. The amount of sodium acetate is estabUshed by comparing the result to a cahbration curve. A more lengthy method involves the extraction of the PVA with methanol using a Soxhlet extractor. The methanol is evaporated and water is added. The solution is titrated using hydrochloric acid in order to determine the amount of sodium acetate. 

The electrical conductivity of a pure aqueous sodium chlorate solution is given in Table 2. Additional data are given (27). Table 3 summarizes the solubiHty data for two aqueous chlorate—chloride systems (28—30). 

Table 2. Electrical Conductivity of Aqueous Sodium Chlorate Solutions (ohm m—1...

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. 

Furthermore, the electrical conductivities of liquid Na-Sn alloys for the five compositions are determined with the Kubo-Greenwood scheme, using the trajectories from our ab initio MD simulations. The calculated values reproduce the measured strong variation of the conductivity with the Na (or Sn) concentration very well. The small (semimetallic) conductivity of the alloys with nearly equimolar composition can be explained by the position of the Fermi energy between the occupied sp-band of tin and the sp-band of sodium. 

Thus we find great variation among solutions. Iodine dissolves in ethyl alcohol, coloring the liquid brown, but does not dissolve readily in water. Sodium chloride does not dissolve readily in ethyl alcohol but does dissolve in water, forming a solution that conducts electric current. Sugar dissolves readily both in ethyl alcohol and in water, but neither solution conducts electric current. These differences are very important to the chemist, and variations in electrical conductivity are among the most important. We shall investigate electrical conductivity further but, first, we need to explore the electrical nature of matter. 

When we study a solid that does not have the characteristic lustrous appearance of a metal, we find that the conductivity is extremely low. This includes the solids we have called ionic solids sodium chloride, sodium nitrate, silver nitrate, and silver chloride. It includes, as well, the molecular crystals, such as ice. This solid, shown in Figure 5-3, is made up of molecules (such as exist in the gas phase) regularly packed in an orderly array. These poor conductors differ widely from the metals in almost every property. Thus electrical conductivity furnishes the key to one of the most fundamental classification schemes for substances. 

Molten lithium fluoride and sodium chloride have easily measured electrical conductivities. Nevertheless, these conductivities are lower than metallic conductivities by several factors of ten. Molten sodium chloride at 750°C has a conductivity about IQ-5 times that of copper metal at room temperature. It is unlikely that the electric charge moves by the same mechanism in molten NaCl as in metallic copper. Experiments show that the charge is carried in molten NaCl by Na+ and Cl- ions. This electrical conductivity of the liquid is one of the most characteristic... 

It is appropriate to refer here to the development of non-suppressed ion chromatography. A simple chromatographic system for anions which uses a conductivity detector but requires no suppressor column has been described by Fritz and co-workers.28 The anions are separated on a column of macroporous anion exchange resin which has a very low capacity, so that only a very dilute solution (ca 10 4M) of an aromatic organic acid salt (e.g. sodium phthalate) is required as the eluant. The low conductance of the eluant eliminates the need for a suppressor column and the separated anions can be detected by electrical conductance. In general, however, non-suppressed ion chromatography is an order of magnitude less sensitive than the suppressed mode. 

The main criteria for the selection of the current collector material in a central sulfur cell or for the cell case material in a central sodium cell are corrosion resistance to sulfur and sodium polysulfides, good electrical conductivity, and low costs. This cost argument has led to coated materials which have been compared with nickel—chromium alloys (Inconel 600). 

Steam purity indicates the degree of inadvertent BW carryover, typically reflected by an increase in electrical conductivity from sodium and other ions present in the BW TDS. Iron and silica may also carry over, and the silica may be in a volatile form. Steam purity also is affected by the use of neutralizing amines (as an intentional measure). 

The purity of steam can be measured by an increase in electrical conductivity. Testing for sodium ions (Na+) is particularly useful because almost without exception, all BW contains sodium ions. 

Testing for steam purity measures the degree of carryover (typically indicated by an increase in electrical conductivity) and provides a starting point for evaluations into specific types of contaminants such as iron, silica, and sodium. 

The conductivity of sodium dodecyl sulfate in aqueous solution and in sodium chloride solutions was studied by Williams et al. [98] to determine the CMC. Goddard and Benson [146] studied the electrical conductivity of aqueous solutions of sodium octyl, decyl, and dodecyl sulfates over concentration ranges about the respective CMC and at temperatures from 10°C to 55°C. Figure 14 shows the results obtained by Goddard and Benson for the specific conductivity of sodium dodecyl sulfate and Table 25 shows the coefficients a and p of the linear equation of the specific conductivity, in mho/cm, vs. the molality of the solution at 25°C. Micellization parameters have been studied in detail from conductivity data in a recent work of Shanks and Franses [147]. 

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