Nitrate melt

The acidic properties of oxides increased in the sequence V205 P205 As205. Besides of reactions [10.4.30]-[10.4.32], the constants of the following assumed equilibria, with participation of hydroanions HPO/, H2PO4, HAs04, H2As04, were determined  

Since even the pure salts eontaining mentioned hydroanions undergo the decomposition at temperatures much lower then 350 C with the formation of corresponding meta- or pyro- salts, equilibria [10.4.33] and [10.4.34] hardly take plaee in the absence ofwater vapor in atmosphere over the melt. 

The equilibrium constants have incorrect values beeause calculated magnitudes had shift by order of a few pK units. Such phenomenon may take place either because of incorrect determination of reaction participants (stoichiometry) or slope changes of the calibration plot for the used oxygen electrode Pt(02) in the acidic region. 

Relative acidities of different metal cations in molten KNO3 h ve been investigated using potentiometric titration of corresponding carbonates by dichromate and metaphosphate ions  

the use of a majority of proposed bases for quantitative studies of oxoacidity is not possible, especially for acids having apparent oxidizing properties (chromates, vanadates, etc.). 

2H2RO4 +0 =2HROl -l-HjOt 2HROl +0 =2ROl- d-HjOt 

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To a stirred and refluxing solution of 40 parts of benzene and 35 parts of dimethylformamide (both solvents previously dried azeotropically) are added successively 1.6 parts of sodium hydride and 7.7 parts of Ct-(2,4-dichlorophenyl)imidazole-1-ethanol, (coolingon ice is necessary). After the addition is complete, stirring and refluxing is continued for 30 minutes. Then there are added 7.8 parts of 2,6-dichlorobenzyl chloride and the whole is stirred at reflux for another 3 hours. The reaction mixture is poured onto water and the product 1-[2,4-dichloro-/3 (2,6-dichlorobenzyloxy)phenethyl] imidazole, is extracted with benzene. The extract is washed twice with water, dried, filtered and evaporated in vacuo. The bese residue is dissolved in a mixture of acetone and diisopropyl ether and to this solution is added an excess of concentrated nitric acid solution. The precipitated nitrate salt is filtered off and recrystallized from a mixture of methanol and diisopropyl ether, yielding 1-[2,4-dichloro- (2,6-dichlorobenzyl-oxv)phenethyl] imidazole nitrate melting point 179°C. 

Access of air to the melt can be reduced by fitting a cover over it, or by floating a layer of powdered graphite on the melt surface. Diffusion rates in the melt can be reduced only by lowering the temperature, and this invariably reduces the amount of corrosion (except in certain cases in nitrate melts where passivity effects occur ). 

The effect of highly polarizable cations on transport properties has scarcely been studied. Since the nitrate melts of Ag and TL are stable and have high polarizabilities, as shown in Table 5, their internal mobilities in binary mixtures containing one or both of these cations have been measured frequently. The isotherms are shown for and m,., in Figs. 10 and 11,... 

Some Fundamental Properties of Alkali Metal, Ag(I) and T1(I) Ions and their Nitrate Melts... 

It is important from a practical viewpoint to predict the shear viscosity of mixtures from those of pure melts. For alkali nitrate melts, a linear dependence has been found between the reorientational line width obtained by Raman measurements and the ratio of temperature divided by shear viscosity.For NO3 ions, the depolarized Raman scattering from 1050cm" total stretching vibrational mode (Al) has a contribution to the line width L, which is caused by the reorientational relaxation time of the Csv axis of this ion. The Stokes-Einstein-Debye(SED) relation establishes a relation between the shear viscosity r of a melt and the relaxation time for the reorientation of a particle immersed in it ... 

Tkalenko D.A. Electrochemistry of nitrate melts. Kiev Naykova Dumka, 1983 (in Russian). 

A potentiometric study of polymeric anions of molybdenum in nitrate melts has resolved apparent contradictions in earlier work and confirmed that [Mo207] ", rather than [Mo30,o] , is the polymeric anion in equilibrium with [MoOj ] The crystal structure of K2[Mo,07] has been shown to involve chains of M0O4 tetrahedra and MoO octahedra " and the dissociation of molten Na2[W207] to Na and a mixture of anions including [W04], [W207] , and has been confirmed. " The results of other... 

Actually, the more interesting situation is (b) where the conjugate acid is an oxidizing agent (12). A striking demonstration of the interdependence of electron transfer and oxide transfer is inherent in the following observations. It is possible to prepare a solution of potassium iodide in a very pure nitrate melt and maintain... 

Figure C. Polarograms for a nitrate alkali nitrate melt containing traces of water...

Harry Gray I would like to ask Dr. Gruen about the nitrate melts. 

Trinitrohydroxyethylbenzene nitrate or trinitrophenyl-/J-ethyl nitrate, melting at 83°C, is obtained from trinitrotoluene, that undergoes an addition reaction with formaldehyde in an alkaline medium to produce the corresponding alcohol (m.p. 112°C), which is then nitrated (Vender [87]) ... 

There has been a trend toward the production of ammonium phosphates in powder form, Concentrated phosphoric acid is neutralized under pressure, and the heat of neutralization is used to remove the water in a spray tower. The powdered product then is collected at the bottom of the tower. Ammonium nitrate/ammonium phosphate combination products can be obtained either by neutralizing mixed nitric acid and phosphoric acid, or by the addition of ammonium phosphate to an ammonium nitrate melt. 

Several isovalent ions form solid solutions with KTP (Table II), showing that this structure is relatively tolerant, with respect to isovalent impurities, as are the traditional nonlinear optical oxide crystal structures. But due to the relatively limited range of nonstoichiometry in KTP, aliovalent impurities, such as divalent Ba, Sr and Ca introduced through ion exchange in nitrate melts, which substitute on the K site, are incorporated at concentrations less than one mole percent.(36) Typical impurity concentrations present in flux and hydrothermally grown KTP are shown in Table ID. 

The product, l-[2,4-dichloro-p-(2,4 -dichlorobenzyloxy)phenethyl]imidazole, is extracted with benzene. The extract is washed with water, dried, filtered and evaporated in vacuo. From the residual oily free base, the nitrate salt is prepared in the usual manner in 2-propanol by treatment with concentrated nitric acid, yielding, after recrystallization of the crude solid salt from a mixture of 2-propanol, methanol and diisopropyl ether, l-[2,4-dichloro-p-dichlorobenzyloxy)phenethyl]imidazole nitrate melting point 170.5°C. 

Blasting agents are powerful explosive agents that cannot be detonated by means of a blasting cap when unconfined and are, therefore, very safe to handle. A powerful booster is needed to start detonation. Blasting agents are usually ammonium nitrate (melting point 169.6°C, density 1.725) mixtures sensitized with nonexplosive fuels such as oil or wax. 

Silver(i).—Group VII Donors. A study of the phase equilibria of the AgI-NaI-HzO system has previously led to the isolation of the compound AgI,NaI,3H20 194 u.v-visible spectra and X-ray powder studies indicate the formulation Na[AgI2],3H20.195 The phase transition for the system AgI-I -(KNa)N03 at 280 °C has been studied at high iodide concentrations.196 The results indicate the presence of [Agl4]3 and polynuclear species. Thermodynamic calculations on the distribution of Agl between solid or liquid (K2Ag)I and a nitrate melt have been reported.197 It was concluded... 

The silver-silver Ion electrode. Of the reversible metal electrodes, silver has been most often employed. There is only one stable oxidation state of silver above 300°C there is no danger of oxide formation because Ag20 is unstable.57 The metal has no observable tendency to dissolve in molten silver salts and is highly reversible in mixed chloride and nitrate eutectics. The Ag(I) ion can be introduced into the melt by either adding silver nitrate to a nitrate melt (AgCl to a chloride melt) or by anodizing a silver electrode. The potentials of silver nitrate concentration cells show ideal thermodynamic behavior up to 0.5 mol % in (Na,K)N03 eutectic and in NaN03.58... 

Green rhombohedral crystals of iron(II) nitrate hexahy-drate, Fe(N03)2-6H20 (ferrous nitrate), with a melting point 60.5 °C, are obtained from solutions made by dissolving iron in dilute nitric acid. With more concentrated acid, oxidation takes place, and monoclinic pale violet iron(III) nitrate non-ahydrate, Fe(N03 )s -91120 (ferric nitrate), melting point 47 °C, may be crystallized. A colorless hexahydrate can also separate as cubic crystals. Various basic iron(in) nitrates have been described. The eight-coordinate iron(in) anion [Fe(N03)4] has an essentially dodecahedral symmetry with four almost symmetrical bidentate nitrate groups. ... 

Fill one-third full of crystals of ammonium nitrate, adjust the apparatus, and heat A gently with a low flame., The ammonium nitrate melts and appears to boil. 

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