Nitrate potassium

Potassium nitrate is produced by reacting potassium chloride with nitric acid  

The process is in fact much more complex than this equation indicates. 

In analogy with the manufacture of potassium sulfate, potassium nitrate can also be manufactured by metathesis with other nitrates, e.g. with sodium, calcium or ammonium nitrate, as follows  

Chemical Economics Handbook. 11/1997. World Fertilizer Overview, Stanford Research Institute, Menlo Park, California, USA. 

Potassium Nitrate, KN03, from Sodium Nitrate and Potassium Chloride 

Solubility plays a controlling part in many chemical processes of which the present one is a typical example. 

When sodium nitrate and potassium chloride are dissolved, the solution contains four ions, Na+, NOa , K+, CP, and from these ions not only could the two original salts be reconstructed, but also two new salts, potassium nitrate and sodium chloride, through a regrouping of the radicals. Which of the four salts will crystallize from a solution containing the four ions depends solely 

A very important fact concerning solubilities is that the solubility of a given salt is practically unaffected by the presence of another salt in the solution, provided only that the other salt does not possess one of the same ions as the first salt. 

For example, suppose that sodium nitrate and potassium chloride in equivalent amounts are added to 100 grams of water at 10°, so that the total weight of K+ and N03 radicals will be 42 grams the potassium nitrate in excess of its solubility will then crystallize out, and 21 grams of the crystals will thus be obtained. The presence of the radicals of sodium chloride in the solution is without effect on the potassium nitrate. 

Potassium nitrate is best known as the oxidizing agent in old-fashioned black powder gunpowder, which is 75 percent potassium nitrate by weight. The other ingredients are 15 percent charcoal and 10 percent sulfur. 

But potassium nitrate is also used in toothpastes that are formulated to make teeth less sensitive to pain. As gums recede and the tooth root dentin becomes exposed, teeth can become hypersensitive to hot or cold foods. Potassium nitrate interferes with the transmission of pain signals in the nerves of the teeth. 

Potassium nitrate is also found in pills for backache and joint pain. It makes a decent plant fertilizer, providing nitrogen and potassium but no phosphorus. As an oxidizer, it is an ingredient in stump removers that hastens the decay of tree stumps. And it is used as a preservative in some salted meats like nitrites, it helps to preserve the color of the meat. 

Potassium nitrate (saltpeter, KN03) is manufactured in two ways (1) by reacting nitric acid with potassium chloride with a chlorine by-product and (2) by reacting sodium nitrate with potassium chloride and crystallizing out the salt. 

Potassium nitrate is used in the manufacture of fertilizers, explosives, ceramics, and heat-treating salts. 

Potassium nitrate (poe-TAS-ee-yum NYE-trate) is transparent, colorless, or white, and may be crystalline or powdery solid. It is odorless with a sharp, cool, salty taste. It is slightly hygroscopic, that is, having a tendency to absorb moisture from the air. Potassium nitrate, more commonly known as saltpeter or niter, has been used by humans for many centuries. Going hack as far as ancient Chinese civilizations, the compound was used as an ingredient in fireworks, to preserve foods, to make incense burn more evenly, to increase the male sex drive, and for magic potions. 

The compound can also he obtained for use from natural sources. It occurs as a thin, whitish, glassy crust on rocks in 

Potassium nitrate. Red atoms are oxygen blue atom is nitrogen and turquoise atom is potassium, publishers 

At one time, potassium nitrate was prepared by mixing manure with mortar or wood ash, soil, and an organic material, such as straw. The bed was kept moist with urine and turned often to speed decomposition of the organic matter. After a year, the bed was thoroughly watered, dissolving the potassium nitrate that had accumulated. It was then recrystallized and purified. 

In 1862, leaders of the Confederate Army ordered a chemistry professor at South Carolina College to teach farmers how to make potassium nitrate to ensure an adequate supply of the compound for use in making gunpowder. 

CHEMICAL NAME = potassium nitrate CAS NUMBER = 7757-79-1 MOLECULAR FORMULA = KN03 MOLAR MASS =101.1 g/mol COMPOSITION = K(38.7%) N(13.8%) 0(47.5%) 

The potassium nitrate used in gunpowder was originally obtained from natural mineral deposits of niter. Small quantities formed as efflorescence deposits on damp stone walls were 

The process of saltpeter production involved mixing the dirt with ashes to keep the pH neutral and then refining and separating the saltpeter. 

Although the most prominent use of saltpeter is for the production of black powder, potassium nitrate is also used as fertilizer. In the first half of the 17th century, Johann Rudolf Glauber (1604-1668) obtained saltpeter from animal pens and discovered its use to promote plant growth. Glauber included saltpeter with other nutrients in fertilizer 

The Germans need to supplant Chilean saltpeter supply, which could be cut off by enemy blockades, led to the search for methods to synthesize nitrates. The reaction required a supply of ammonia, which was economically synthesized by Fritz Haber (1868—1934) before World War I (see Ammonia). Ammonia could then be converted to nitric acid through the Ostwald process and then nitric acid can be reacted with bases to produce nitrates (see Nitric Acid) KOH + HNO 4 - KNO. + HO 

Data reported for the protolysis constant of water in potassium nitrate media are listed in Table 5.27. The data are solely for a temperature of 25 C, covering a range to 2.5 mol 1 (2.8 molkg ) only. 

Robinson and Stokes (1959) listed osmotic coefficient data for potassium nitrate solutions. Water activity data were derived from these data using Eq. (5.18). The dependence of the water activity data on the ionic strength in potassium nitrate solutions can be described using Eq. (5.19), and the values derived for and 2 are 0.02932 0.00026 X 10 and -2.73 0.10 x 10 kg mol , respectively. 

EXPLOSIVE WHEN MIXED WITH COMBUSTIBLE MATERIALS 

Mixtures of potassium nitrate and combustible materials are readily ignited mixtures with finely divided combustible materials can react explosively.2 

Soluble in water and glycerol insoluble in absolute alcohol.1 

Metals. Mixtures with powdered Ti, Sb, or Ge explode on heating.3 

Metal Sulfides. Mixtures with antimony trisulfide, barium or calcium sulfides, or germanium monosulfide or titanium disulfide explode on heating4-6 mixtures with arsenic disulfide6 or molybdenum disulfide7 are detonatable. 

No solid residue remains in the high temperature region above 970 K. 

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The reaction is exothermic, and multitubular reactors are employed with indirect cooling of the reactor via a heat transfer medium. A number of heat transfer media have been proposed to carry out the reactor cooling, such as hot oil circuits, water, sulfur, mercury, etc. However, the favored heat transfer medium is usually a molten heat transfer salt which is a eutectic mixture of sodium-potassium nitrate-nitrite. 

Steam is by far the most widely used medium, useful up to about 475 K. Up to about 700 K organic liquids such as the dowtherms and mineral oil may be used. Mercury and molten salts, such as the eutectic mixture of sodium nitrite, sodium nitrate and potassium nitrate may be used up to 875 K, while above this temperature air and flue gases must be used. 

The reduction of a nitrate, for example potassium nitrate, by iron(ll) sulphate in the presence of concentrated sulphuric acid gives reasonably pure nitrogen monoxide. The mixture is warmed and at this temperature the nitrogen monoxide produced does not combine with uncharged iron(II) sulphate (see below). 

Nitric acid is prepared in the laboratory by distilling equal weights of potassium nitrate and concentrated sulphuric acid using an air condenser, the stem of which dips into a flask cooled by tap water. The reaction is ... 

Fusion of any chromium compound with a mixture of potassium nitrate and carbonate gives a yellow chromate(VI). ... 

Fused potassium nitrate is a powerful oxidising agent (cf. the oxidation of manganese compounds, p.. IS6 ... 

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

In preparing this mixture, the lactose and the potassium nitrate should be powdered separately and then mixed solely by shying. They should not be ground together in a mortar. 

The use of an equivalent quantity of A.R. potassium nitrate is said to produce a more active catalyst. 

The preparation of a number of miscellaneous acids is described. m-Nitrobenzoic acid. Although m-nitrobenzoic acid is the main product of the direct nitration of benzoic acid with potassium nitrate and concentrated sulphuric acid, the complete separation of the small quantity of the attendant para isomer is a laborious process. It is preferable to nitrate methyl benzoate and hydrolyse the resulting methyl w-nitrobenzoate, which is easily obtained in a pure condition ... 

Sodium nitrate (NaN03) and potassium nitrate (KNO3) are formed by the... 

In determining the values of Ka use is made of the pronounced shift of the UV-vis absorption spectrum of 2.4 upon coordination to the catalytically active ions as is illustrated in Figure 2.4 ". The occurrence of an isosbestic point can be regarded as an indication that there are only two species in solution that contribute to the absorption spectrum free and coordinated dienophile. The exact method of determination of the equilibrium constants is described extensively in reference 75 and is summarised in the experimental section. Since equilibrium constants and rate constants depend on the ionic strength, from this point onward, all measurements have been performed at constant ionic strength of 2.00 M usir potassium nitrate as background electrolyte . 

Potassium nitrate anticatalysed nitration in nitric acid (the solutions used also contained 2-5 mol 1 of water) but the effect was small in comparison with the corresponding effect in nitration in organic solvents ( 3.2.3 4), for the rate was only halved by the addition of 0-31 mol 1 of the salt. As in the case of the addition of sulphuric acid, the effect was not linear in the concentration of the additive, and the variation of k j with [KNOgj/mol 1 " was similar to that of with [H2SO4]/ mol 1. ... 

The effect of potassium nitrate on the rate arises in a similar way. The concentration of nitrate ions in concentrated nitric acid is appreciable, and addition of small quantities of nitrate will have relatively little effect. Only when the concentration of added nitrate exceeds that of the nitrate present in pure nitric acid will the anticatalysis become proportional to the concentration of added salt. 

The ultraviolet spectra of solutions of potassium nitrate in various concentrations of sulphuric acid have been studied, and absorptions... 

TABLE 3.4 The effects of potassium nitrate on rates of nitration in nitromethane... 

The addition of water depresses zeroth-order rates of nitration, although the effect is very weak compared with that of nitrate ions concentrations of 6x io mol 1 of water, and 4X io mol 1 of potassium nitrate halve the rates of reaction under similar conditions. In moderate concentrations water anticatalyses nitration under zeroth-order conditions without changing the kinetic form. This effect is shown below (table 3.5) for the nitration of toluene in nitromethane. More strikingly, the addition of larger proportions of water modifies the kinetic... 

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—)... 

Organic matter Hot concentrated sulfuric acid plus a few drops of sodium or potassium nitrate solution. 

Titanium Aluminum, boron trifluoride, carbon dioxide, CuO, halocarbons, halogens, PbO, nitric acid, potassium chlorate, potassium nitrate, potassium permanganate, steam at high temperatures, water... 

Nonelectrolytic plant producing chlorine and potassium nitrate. 

Black Powder. Black powder is mainly used as an igniter for nitrocellulose gun propellant, and to some extent in safety blasting fuse, delay fuses, and in firecrackers. Potassium nitrate black powder (74 wt %, 15.6 wt % carbon, 10.4 wt % sulfur) is used for military appHcations. The slower-burning, less cosdy, and more hygroscopic sodium nitrate black powder (71.0 wt %, 16.5 wt % carbon, 12.5 wt % sulfur) is used industrially. The reaction products of black powder are complex (Table 12) and change with the conditions of initia tion, confinement, and density. The reported thermochemical and performance characteristics vary greatly and depend on the source of material, its physical form, and the method of determination. Typical values are Hsted in Table 13. 

Typically, dry potassium nitrate is pulverized in a ball mill. Sulfur is milled into cellular charcoal to form a uniform mix in a separate ball mill. The nitrate and the sulfur—charcoal mix are screened and then loosely mixed by hand or in a tumbling machine. Magnetic separators may be used to ensure the absence of ferrous metals. The preliminary mix is transferred to an edge-mimer wheel mill with large, heavy cast iron wheels. A clearance between the pan and the wheels is required for safety purposes. The size of this gap also contributes to the density of the black powder granules obtained. Water is added to minimize dusting and improve incorporation of the nitrate into the charcoal. The milling operation requires ca 3 to 6 h. 

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