NJL
The Chemistry of Sodium and its Compounds
1. Discovery and Naming of Sodium
Sodium, in the form of salt, has been known by man for many, many centuries. Indeed, man's use of salt to season food was the basis for one of the earliest examples of international trade the journeying of caravans in biblical days to Sodom, Gomorrah and nearby cities to obtain this valuable commodity from the Romans who controlled the salt deposits near the Dead Sea.
Source: Comprehensive Inorganic Chemistry (J.C. Bailar et al.) Page 390 (WSU Library QD 451.2 C64 V.1)
The Egyptians called soda natron. Much later, the Romans used a similar name for the compound, natrium. These names explain the chemical symbol used for sodium, Na. The name sodium probably originated from an Arabic word suda, meaning "headache." Soda was sometimes used as a cure for headaches among early peoples. The word suda also carried Dyer into Latin to become sodanum, which also means "headache remedy."
Source: Chemical Elements (David E. Newton) Page 542 (WSU Reference QD 466.N464 1999V.3)
2. Occurrence and Extraction of Sodium
Sir Humphry Davy first isolated metallic sodium in 1807 by the electrolytic decomposition of sodium hydroxide. Later, the metal was produced experimentally by thermal reduction of the hydroxide with iron. In 1855, commercial production was started using the Deville process, in which sodium carbonate was reduced with carbon at 1100°C. In 1886 a process for the thermal reduction of sodium hydroxide with carbon was developed. Later sodium was made on a commercial scale by the electrolysis of sodium hydroxide. The process for the electrolytic decomposition of fused sodium chloride, patented in 1924, has been the preferred process since installation of the first electrolysis cells at Niagara Falls in 1925. Sodium chloride decomposition is widely used throughout the world.
Source: Encyclopedia of chemical technology fifth Edition volume 22 page 760 (WSU Reference TP9.K54 2004 V.22)
Sodium [is an] abundant element, its principal sources being rock salt (NaCI), natural brines and sea water. Rock salt is almost pure sodium chloride, and sodium chloride is the major
component of dissolved solids in the sea to a degree sufficient for it to be readily obtainable in warm climates by evaporation of sea water.
Source: Inorganic Chemistry (A. G. Sharpe) page 228 (WSU Library QD151.2.S48 1991)
3. General Properties of Sodium
Sodium is a soft, malleable solid readily cut with a knife or extruded as wire. It is commonly coated with a layer of white sodium monoxide, carbonate, or hydroxide, depending on the degree and kind of atmospheric exposure. In a strictly anhydrous inert atmosphere, the freshly cut surface has a faintly pink, bright metallic luster. Liquid sodium in such an atmosphere looks much like mercury. Both liquid and solid oxidize in air, but traces of moisture appear to be required for the reaction to proceed. Oxidation of the liquid is accelerated by an increase in temperature, or by increased velocity of sodium through an air or oxygen environment.
Source: Encyclopedia of chemical technology fifth Edition volume 15 page 761 (WSU Reference TP9.K54 2004 V.22)
4. Uses of Sodium Metal
Metallic sodium is used in the extraction of titanium, for the production of sodium cyanide and sodium peroxide and, used in conjunction with an alcohol, for the industrial reduction of fatty acids. Sodium is utilized as a heat transfer medium in some atomic power stations. Other applications of sodium and its alloys include the familiar yellow street lights, photoelectric cells, with potassium in high-temperature thermometers and with lead as an intermediary in the manufacture of tetraethyl lead (now discredited for health reasons).
Source: Comparative Inorganic Chemistry (Bernard Moody) Page 216 (WSU Library QD 151.2.M66 1991)
Sodium [metal] was first used commercially to make aluminum by reduction of sodium aluminum chloride. The principal application as of the mid-1990s is for the manufacture of tetraethyllead (TEL), the antiknock gasoline additive. However, TEL use is declining worldwide because of the recognized toxic effects of lead released to the environment Sodium use is growing for manufacture of sodium borohydride and agricultural crop protection chemicals Smaller amounts of sodium are used to produce sodium hydride, indigo dyes, tantalum metal powders, silicon, and sodium peroxide; in the preparation of many organic compounds, pharmaceuticals sodium azide, and copper; and in lead dross refining.
Source: Encyclopedia of chemical technology fifth Edition volume 22 page 760 (WSU Reference TP9.K54 2004 V.22)
Many former uses of sodium metal have been discontinued because of the development of cheaper competitive routes. For example, the first commercial use of sodium metal in the mid-nineteenth century involved its use in the reduction of aluminum chloride to produce aluminum metal; Hall's classic work on the cheaper electrolytic route to aluminum deprived sodium of its first industrial market. Similarly, its early use to produce NaCN by fusion with potassium ferrocyanide was displaced later by the reaction of sodium with ammonia and coke, and ultimately by the direct synthesis of hydrogen cyanide as a cyanide source. Sodium metal was also used formerly in large quantities to produce fatty alcohols for synthetic detergents by reduction of natural esters; however, the use of hydrogen reduction to produce alkylaryl sulphonates (as substitutes for the more expensive fatty alcohol sulphates) has almost completely eliminated this market for sodium.
Source: Comprehensive Inorganic Chemistry (J.C. Bailar et al.) Page 373 (WSU Library QD 451.2 C64 V.1)
5. Sodium Hydride
Sodium hydride is a useful condensation catalyst. It possesses considerable advantages over the other condensing agents, such as Na, NaOH, NaOR, NaNH2: (i) it acts more vigorously and more rapidly, (ii) no relatively large excess needs to be used, (iii) neither water nor alcohol is produced, (iv) there are few side reactions and reductions, (v) the hydrogen formed serves as a measure of the extent of reaction A suspension of NaH in oil is particularly suitable, since the particles are then protected against superficial oxidation. For condensations normally requiring days, hours (and frequently only minutes) are often sufficient when they are catalyzed with suspensions of NaH in oil, and generally, in addition, the reaction temperature can also be lowered.
Source: Hydrides (Wiberg and Amberger) page 33 (WSU Library QD 181.H1.W513)
6. Sodium Chloride
Common salt has played a major role in the history of civilization. Salt was one of the earliest commodities to be traded, and Roman soldiers were partially paid in salt (sal) hence our term for wages, salary. In central Europe during the Middle Ages, the Catholic Church controlled the salt mines, a source of wealth and power. Centuries later, the salt taxes in France were part of the cause of the French Revolution.
More sodium chloride is used for chemical manufacture than any other mineral, with world consumption exceeding 150 million tones per year.
Source: Descriptive Organic Chemistry second edition (Geoff Rayner-Canham) Page 200 (WSU Library QD 151.5.R39 1999)
Sodium chloride structure: the radius ratio is 0.52 and this suggests an octahedral arrangement. Each Na+ ion is surrounded by six CI- ions at the corners of a regular octahedron and similarly each Cl- ion is surrounded by six Na+ ions. The coordination is thus 6:6.
Source: Concise Inorganic Chemistry Fifth Edition (J. D. Lee) pages 47-48 (WSU Library QD 453.2.L44.1996)
Rock salt, solar salt, and to some degree, evaporated salt are used to maintain traffic safety and mobility during snow and ice conditions in Snowbelt regions worldwide. Sodium chloride melts ice at temperatures down to its eutectic point of -21.12°C. Most snowstorms occur when the temperature is near O°C, where salt is very effective. More than 40% of dry salt produced in the United States is used for highway deicing.
Source: Encyclopedia of chemical technology fifth Edition volume 22 page 817 (WSU Reference TP9.K54 2004 V.22)
7. Sodium Carbonate
Sodium carbonate Na2CO3, also known as soda ash, is produced from both natural deposits and synthetic methods based on the Solvay process. Annual world production capacity is estimated at almost 44 x 106 metric tons. It is an essential ingredient in the production of glass, chemicals, soaps, detergents, pulp and paper.
Source: Encyclopedia of chemical technology fifth Edition volume 22 page 787 (WSU Reference TP9.K54 2004 V.22)
The Solvay process essentially is a process for converting salt and limestone to soda ash and calcium chloride by a type of metathesis, although one would scarcely recognize a metathetical [double displacement] reaction from the various chemical reactions involved. In essence, the Solvay process may be said to be a commercial way of combining the sodium ion from salt with the carbonate ion from limestone to produce sodium carbonate.
Source: Comprehensive Inorganic Chemistry (J.C. Bailar et al.) Page 453 (WSU Library QD 451.2 C64 V.1)
[I know this isn’t directly Na related, however I found it interesting and thought you might as well]
World production of Na2CO3 in 1993 was 31.5 million tones, and 49% of this was used in the glass industry. Smaller amounts were used to make various sodium phosphates and polyphosphates which are used for water softening (being added to various cleaning powders), and in wood pulp and paper making. The increased awareness of the effect of 'acid rain' on plants and buildings has led to a new use for Na2CO3 in treating the flue gases from coal- and oil-fired power stations, to remove SO2 and H2SO4.
Source: Concise Inorganic Chemistry fifth edition (J.D. Lee) page 322 (WSU Library QD 453.2.L44 1996)
Sodium hydrogen carbonate [sodium bicarbonate] is less water soluble than sodium carbonate.
Thus it can be prepared by bubbling carbon dioxide through a saturated solution of the carbonate:
Na2CO3(aq) + CO2 (g) + H20(l) ↔ 2 NaHCO3(s)
Heating sodium hydrogen carbonate causes it to decompose back to sodium carbonate:
2 NaHCO3(s) ↔ Na2CO3(aq) + CO2 (g) + H20(g)
This reaction provides one application of sodium hydrogen carbonate, the major component in dry powder fire extinguishers. The sodium hydrogen carbonate powder itself smothers the fire, but, in addition, the solid decomposes to give carbon dioxide and water vapor, themselves fire-extinguishing gases.
The main use of sodium hydrogen carbonate is in the food industry, to cause bakery products to rise. It is commonly used as a mixture (baking powder) of sodium hydrogen carbonate and calcium dihydrogen phosphate, Ca(H2PO4)2 with some starch added as a filler. The calcium dihydrogen phosphate is acidic and, when moistened, reacts with the sodium hydrogen carbonate to generate carbon dioxide:
2 NaHCO3(s) + Ca(H2PO4)2(S) -+ Na2HPO4(s) + CaHPO4(s) + 2 CO2(g) + 2 H2O(g)
Source: Descriptive Organic Chemistry second edition (Geoff Rayner-Canham) Page 200 (WSU Library QD 151.5.R39 1999)
8. Sodium in the Body
[Sodium is] among the 25 or so elements now thought to be essential for animal life. It performs electrophysiological functions based on the fact that the Na+:K+ concentration ratio is different in the fluids inside and outside cells. Due to these concentration gradients across cell membranes, a potential difference is set up and this is responsible for the transmission of nerve impulses.
Source: Encyclopedia of chemical technology fifth Edition volume 1 page 36 (WSU Reference TP9.K54 2004 V.1)
9. Sodium Ions
It is so easy to become locked into preconceptions. Everyone "knows" that the alkali metals "want" to lose an electron and form cations. In fact, this is not true. Left to itself, the alkali metal would prefer to complete its s orbital set by gaining an electron.
It was a Michigan State chemist, James Dye, who realized that the alkali metals have such positive electron affinities that it might just be possible to stabilize the alkali metal anion. After a number of attempts, he found a complex organic compound of formula C2oH3606 that
could just contain a sodium cation within its structure. He was hoping that, by adding this compound to a sample of sodium metal, some of the sodium atoms would pass their s electrons to neighboring sodium atoms, to produce sodium anions. This happened, as predicted:
2 Na(s) + C20H3606 - [Na(C20H3606)]+•Na-
The metallic-looking crystals were shown to contain the sodium anion, but the compound was found to be very reactive with almost everything. So, to the present day, this compound is no more than a laboratory curiosity. But its existence does remind us to question even the most commonly held beliefs.
Source: Descriptive Organic Chemistry second edition (Geoff Rayner-Canham) Page 183 (WSU Library QD 151.5.R39 1999)
[I included this section because the most common mention of Na in the literature was simply as a cation. That really seems to be all that most people, myself included, think about when they consider sodium]
10. Sodium Hydroxide
Caustic soda [sodium hydroxide] is the strongest alkali commonly manufactured. It is produced in various grades. Much of the total production of very pure alkali goes into the rayon industry and it is supplied to textile manufacturers for the mercerization of cotton, bleaching and dyeing processes and in paper-making; The hydrolysis (saponification) of natural oils and fats, by boiling with caustic soda solution, produces soap, as a mixture of sodium salts of certain organic acids (e.g. sodium stearate) and the trihydric alcohol, glycerol. Caustic soda is used in the removal of acidic compounds, such as phenol and the cresols, during the refining of coal tar. At least 400 products of the chemical industry require the use of caustic soda at some stage of their manufacture.
Source: Comparative Inorganic Chemistry (Bernard Moody) Page 208 (WSU Library QD 151.2.M66 1991)
Alkali and chlorine products are a group of commodity chemicals which include chlorine Cl2; sodium hydroxide (caustic soda), NaOH; sodium carbonate (soda ash), Na2CO3; potassium hydroxide (caustic potash) KOH; and hydrochloric acid HCI. Chlorine and caustic soda are the two most important products in this group, ranking among the top ten chemicals in the United States.
Electrolysis of sodium chloride accounts for nearly all of today's installed capacity for sodium hydroxide.
2 NaCl + 2 H2O --+ 2 NaOH + Cl2 + H2
As shown, chlorine is coproduced, so companies that are in the sodium hydroxide business are also usually involved in the chlorine business.
Source: Encyclopedia of chemical technology fifth Edition volume 22 page 760 (WSU Reference TP9.K54 2004 V.22)
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