Potassium nitrate solubility

Hitec Heat-Transfer Salt. Hitec heat-transfer salt, manufactured by Coastal Chemical Co., is an eutectic mixture of water-soluble inorganic salts potassium nitrate (53%), sodium nitrite (40%), and sodium nitrate (7%). It is suitable for Hquid-phase heat transfer at temperatures of 150—540°C. 

Quantitatively, sulfur in a free or combined state is generally determined by oxidizing it to a soluble sulfate, by fusion with an alkaH carbonate if necessary, and precipitating it as insoluble barium sulfate. Oxidation can be effected with such agents as concentrated or fuming nitric acid, bromine, sodium peroxide, potassium nitrate, or potassium chlorate. Free sulfur is normally determined by solution in carbon disulfide, the latter being distilled from the extract. This method is not useful if the sample contains polymeric sulfur. 

Scotts technology (17) uses fluid-bed (Wurster column) technology to apply polymeric coatings to a number of fertilizer substrates including urea, potassium nitrate, potassium sulfate, and monoammonium phosphate (MAP). The coating material is appHed as a water-borne latex onto the fluidized substrate. As the substrate is fluidized with warm air (40—50°C), water is driven off and the latex coalesces into a continuous film around the fertilizer particle. The particular latex compositions used have selected glass-transition and blocking temperatures, which enable quick removal of the water before the soluble fertilizer core dissolves. This obviates the need to use precoats prior to the latex appHcation. 

The dependence of solubility on temperature affects the mode of crystallization. For example, Figure 4 shows that the solubiUty of potassium nitrate is strongly influenced by the system temperature but that temperature has Httle influence on the solubiUty of sodium chloride. As a consequence, a reasonable yield of KNO crystals can be obtained by cooling a saturated feed solution on the other hand, cooling a saturated sodium chloride solution accomplishes Httle crystallization, and evaporation is required to increase the yield of sodium chloride crystals. 

Lead is not generally attacked rapidly by salt solutions (especially the salts of the acids to which it is resistant). The action of nitrates and salts such as potassium and sodium chloride may be rapid. In potassium chloride the corrosion rate increases with concentration to a maximum in 0.05m solution, decreases with a higher concentration, and increases again in 2m solution. Only loosely adherent deposits are formed. In potassium bromide adherent deposits are formed, and the corrosion rate increases with concentration. The attack in potassium iodide is slow in concentrations up to 0.1m but in concentrated solutions rapid attack occurs, probably owing to the formation of soluble KPblj. In dilute potassium nitrate solutions (0.001 m and below) the corrosion product is yellow and is probably a mixture of Pb(OH)2 and PbO, which is poorly adherent. At higher concentrations the corrosion product is more adherent and corrosion is somewhat reduced Details of the corrosion behaviour of lead in various solutions of salts are given in Figure 4.16. 

Substances which are insoluble or only partially soluble in acids are brought into solution by fusion with the appropriate reagent. The most commonly used fusion reagents, or fluxes as they are called, are anhydrous sodium carbonate, either alone or, less frequently, mixed with potassium nitrate or sodium peroxide potassium pyrosulphate, or sodium pyrosulphate sodium peroxide sodium hydroxide or potassium hydroxide. Anhydrous lithium metaborate has found favour as a flux, especially for materials containing silica 12 when the resulting fused mass is dissolved in dilute acids, no separation of silica takes place as it does when a sodium carbonate melt is similarly treated. Other advantages claimed for lithium metaborate are the following. 

The supporting electrolyte may be 0.5 M potassium nitrate for bromide and iodide for chloride, 0.5 M potassium nitrate in 25-50 per cent ethanol must be used because of the appreciable solubility of silver chloride in water. 

Catalytic elfects on the thermal decomposition and burning under nitrogen of the nitrate were determined for ammonium dichromate, potassium dichromate, potassium chromate, barium chloride, sodium chloride and potassium nitrate. Chromium(VI) salts are most effective in decomposition, and the halides salts during burning of the nitrate [1]. The effect of chromium compounds soluble in the molten nitrate, all of which promote decomposition of the latter, was studied (especially using ammonium dichromate) in kinetic experiments [2],... 

Worked Example 5.5 Calculate the enthalpy of solution A blution) from the following solubilities s of potassium nitrate as a function of temperature T. Values of s were obtained from solubility experiments. 

Potassium iodide, 20 634 Potassium ions, 20 597, 598, 641 in soap-water system, 22 727 Potassium isotopes, 20 598 Potassium magnesium sulfate, 20 626 Potassium manganate(V), 15 592 Potassium manganate(VI), 15 594-596 Potassium metal, 20 604 production of, 20 600 reducing power of, 20 599 Potassium muds, 9 4 Potassium niobate, 17 152-153 Potassium nitrate, 20 609, 634-636 solubility of, 20 636t uses of, 20 636... 

B—A (nitrous acid) and D (acetic acid) are weak acids, and E (ammonia) is a weak base. Weak acids and bases are weak electrolytes. C (ethanol) is a nonelectrolyte. Potassium nitrate (B) is a water-soluble ionic compound. 

It is important to realize that temperature markedly affects the solubility of most substances. For almost all salts, which are solid compounds composed of positive and negative ions (most often composed of both metallic and nonmetallic elements), an increase in temperature leads to an increase in the amount of the salt that will dissolve. Figure 9-2 shows the solubilities of potassium chloride (KCl) and potassium nitrate (KNO3) as a function of temperature. 

Palladium oxide is prepared by heating palladium sponge in oxygen at 350°C. The oxide is obtained as a black powder. The oxide also may be prepared specially for catalytic use by heating a mixture of palladium chloride and potassium nitrate at 600°C and then leaching out water-soluble residue. A hydrated form of the oxide, which is acid soluble can be prepared by precipitation from solution, for example, by hydrolysis of palladium nitrate. The brown hydrated oxide converts to black anhydrous oxide on heating. Its solu-bdity in acids decreases with lowering of water content. 

Sodium chloride is less soluble than KCl, NaNOs and KNO3. It separates out by crystallization. The remaining solution is cooled to ambient temperature. Potassium nitrate crystaUizes out. 

Fusion of polonium dioxide with potassium hydroxide in air, or with potassium nitrate, gives a colorless melt the solubility of the polonium after this treatment corresponds with the solubility data for potassium polonite (12). 

Several tetrammino-derivatives of gold salts have been prepared. When dilute ehloraurie acid saturated with ammonium nitrate is added to a cold saturated solution of ammonium nitrate and the mixture treated with ammonia gas at ordinary temperature, a precipitate of fetrammino-auric nitrate, [Au(NH3)4](N03)3, is obtained. Tctrammino-aurie nitrate is soluble in water and may be crystallised from warm water. It may be precipitated from solution by the addition of any soluble nitrate, but with potassium, sodium, or ammonium nitrate it forms double salts. Thus, potassium nitrate if added to a concentrated solution of tetrammino-auric nitrate forms the compound [Au (NH 3).,] (NO 3)j.KNO. j, which crystallises from solution in needles. 

Thiocyanato-pentammino-chromic Salts, [Cr(NH3)5(SCN)]It2, are prepared by replacing chlorine in chloro-pentammino-chloridc with (SCN) by treating a concentrated aqueous solution containing acetic acid with excess of potassium thiocyanate, warming the solution, and thus obtaining the thiocyanate, [Cr(NH3)5(SCN)](SCN)2. From this the other salts are prepared by double decomposition. The thiocyanate, which has not been obtained pure, is reddish brown in colour and does not crystallise easily it is soluble in cold water, and the aqueous solution gives with hydrochloric acid, potassium bromide, potassium nitrate, potassium iodide, and potassium dichromate, the corresponding salts. 

The solubility of potassium chlorate is depressed by the addition of other potassium salts, or by the addition of other chlorates F. Winteler, and T. Schlosing have measured the solubility of potassium chlorate in potassium chloride soln. and of sodium chlorate in soln. of sodium chloride. In accord with the general rule, the solubility is diminished by the addition of a salt with a common ion. S. Arrhenius measured the solubility of potassium chlorate in aq. soln. of potassium nitrate and C. Blarez in aq. soln. of potassium bromide, chloride, iodide, nitrate, sulphate, oxalate, and hydroxide H. T. Calvert, and J. N. Bronsted in an aq. soln. of the last-named compound. H. T. Calvert also measured the solubility of potassium... 

Sodium carbonate is obtained by adding sodium nitrate to the mother liquid which after the separation of the potassium nitrate corresponded with P2 this carries the point representing the composition of the soln. along P2Pi towards P3. At P2 there is practically no sodium nitrate in soln., and when this salt is added, the solubility of the sodium carbonate is lowered, from 37 7 grms. per litre... 

It will be observed that the m.p. of rubidium nitrate is lower than that of potassium nitrate, while that of caesium nitrate is higher. This is an unusual sequence in the properties of the alkali salts—see the solubilities for another irregularity. 

Sodium and potassium nitrates are soluble in liquid ammonia,38 and the soln. are good electrical conductors. According to F. M. Raoult, the dry salts absorb no ammonia, but a cone. soln. of sodium nitrate dissolves as much ammonia as an equal volume of water, and a cone. soln. of potassium nitrate, more ammonia than water. R. Abegg and H. Riesenfeld found the tension of N, N-, and l 5A-soln. of potassium nitrate in A-soln. of ammonia at 25°, had vap. press. 14 59, 15 61, and 16 75 mm. respectively, when the A-ammonia alone had a vap. press, of 13 45 mm. F. Ephraim prepared lithium tetrammino-nitrate, LiN03.4NH3, as a syrup more stable than the corresponding tetrammino-chloride. The electrical conductivities and the lowering of the f.p. of soln. of potassium nitrate 39 in soln. 

The increased solubility of the potassium nitrate when the cone, of the acid exceeds about 19 47 per cent, is attributed to the formation of acid or hydro-nitrates. 

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