Thorium Nitrate Research Articles

An electrophoretic investigation of the behavior of monodisperse polystyrene latices in solutions of lanthanum, neodymium, and thorium nitrates

The electrophoretic mobilities of monodisperse polystyrene latex particles, varying in diameter from 600 A to 4230 A, have been investigated at constant pH as a function of the concentration of lanthanum and thorium nitrate solutions. Measurements were made in lanthanum nitrate solutions at pH values of 4.5, 5.5, and 7.0 and in thorium nitrate solutions at pH 4.5. Reversal of the charge on the particles occurred at all pH values, and in the case of lanthanum nitrate the reversal of charge concentration was pH dependent. The effect of particle size was found to be small. Investigations were also made of the electrophoretic behavior of the latex particles in 10 −5 M lanthanum and neodymium nitrate solutions as a function of pH. Reversal of charge was observed at pH 4.2 and 7.6 and maxima in positive mobilities occurred at pH 5.4 and 7.1. These results have been considered in terms of the known hydrolysis behavior of the La 3+ and Nd + ions.

Species formed in the potentiometric titration of fluoride with thorium or lanthanum nitrate and functions suitable for the evaluation of the equivalence points

Calculations by means of SILLÉN's HALTAFALL program have been performed on experimental curves by LINGANE for the potentiometric titration of fluoride with thorium and lanthanum in different media. After adjusting the stability constants for some of the main species formed during the titration a good fit was obtained between the experimental data and the calculated titration curves. In the cases where the solution was buffered with acetate it was necessary to consider the formation of mixed fluoride-acetate complexes. Suitable functions for the evaluation of the equivalence point could be derived from the calculations. If the functions: F 1=( v 0+ v)[F -] and F 3=( v 0+ v)[F -] -3 are used before and after the equivalence point, respectively, it ought to be possible to determine fluoride very accurately by titration with lanthanum nitrate in an unbuffered solution. A value proportional to [F -] is obtained from 10 exp (—EF/RT In 10), the Nernst e.m.f. equation.

Properties of Ultrafine Tungsten Powder (I)

The preparation and properties of ultrafine powders of tungsten, tungsten 18.7 % rhenium and thoriated tungsten (4.4% ThO2 for W) are described. The preparation consists of two processes, freeze-drying and reduction with hydrogen at relatively low temperature. According to the desired powder composition, the solution of ammonium paratungstate, the mixed solution of ammonium paratungstate and ammonium perrhenate or the solution of thorium nitrate suspending the fine particles of tungstic acid were frozen rapidly and dryed under the reduced pressure through sublimation. The products thus obtained consist of fine particles having a mean diameter of 0.3-3 microns. The more rapidly the solution was frozen, the finer the particles became. Freeze-dryed powders were reduced with hydrogen at 300-800°C. Metal particles of tungsten or tungsten alloy were obtained above 600°C, and the mean diameter was 0.02-0.1 microns. Inter-particle sintering was observed at higher reduction temperatures, resulting in larger particles.

Microdetermination of sulfur in organic compounds with modified type combustion flask.

An improved combustion flask into which was introduced washing liquid by the reduced pressure to absorb combustion products was used for rapid determination of organic fluorine by titration with thorium nitrate solution (0.01N) using methylthymolblue as an indicator. The washing buffer solution of pH 3.43.5 was prepared by 0.1%. sodium acetate and 10% acetic acid, and the combustion aids were filter paper and gelatin capsule. The flask was heated in warm water just before combustion and cooled in ice water for 1 min. after combustion. Extremely reduced pressure thus obtained enabled only 10 ml of the washing liquid to absorb combussion product effectively and clean up the wall of flask. The solution in the flask was less voluminous than that in conventional procedure, and hence the indicator showed distinctive end point which gave more sensitive results. Only 56 min. was needed for an analysis.

Separation, detection and determination of uranium, thorium, bismuth, and lead in a drop of solution by the ring oven technique

The separation of uranium, lead, bismuth and thorium from a drop of solution containing uranyl acetate, lead nitrate, bismuth nitrate and thorium nitrate has been achieved, using the ring oven technique. The drop was taken on a circular filter paper, treated with1N HNO3 and uranium was washed to the ring zone with n-butanol. Lead was next washed to the ring zone on another filter paper using 20% aqueous ethylenediamine hydrate. The spot was then treated with 1% aqueous sodium diethyldithioearbamate and bismuth was transported to the ring zone on a third paper with ethyl acetate. Finally 0.5N HNO3 was employed to transfer thorium to the ring zone. The separated rings were then compared with standard rings prepared similarly to compute the amounts of the ions present.

The micro determination of cryolite in cordites by the oxygen flask technique

Cryolites in cordite are determined by measuring the concentration of fluoride ion in the products of combustion of the propellant in oxygen. Interfering elements are removed by ion-exchange resin and the fluorine determined either by titration with thorium nitrate or colorimetrically with cerium-alizarin complexone. The method provides a rapid means of isolating inorganic additives from propellant explosive.

Angular distributions of fragments from neutron induced fission of thorium

The angular distributions of fragments of neutron induced fission of thorium are measured with nuclear emulsions loaded with thorium nitrate and exposed to mono-energetic neutron beams in the energy range 1.7 < E n < 5.3 MeV. From the measured angular distributions, we deduce the values of the parameter K 0 2, whose dependence on the excitation energy we compare with that of other even-mass target nuclei.

Radiochemical separation of lead by amalgam exchange

An amalgam exchange technique has been used for the rapid radiochemical separation of lead. A number of variables which affect the exchange were studied and a lead yield of 88.5 %was obtained. At room temperature the procedure requires about 13 min, whereas at 40° it can be completed in about 9 min. Radioactive tracers of 16 different elements were used to check the selectivity of this procedure, which has also been applied for the separation of 212Pb from thorium nitrate solution.

Hydrothermal precipitation in solutions of thorium nitrate, ferric nitrate and aluminium nitrate

Phase diagrams for the systems Th 4+ThO 2H 2O, Fe 3+Fe 2O 3H 2O and Al 3+Al 2O 3 H 2O are determined and presented in the form of temperature-pH plots. The precipitation temperature and the composition of the precipitate formed are shown to be dependent on the pH of the initial nitrate solution. Thermodynamic prediction of phase equilibria in similar systems is outlined.

Improved determination of microgram amounts of lead in food with a radioactive tracer.

Microgram amounts of lead in food are determined by use of a radioactive tracer. The radioactive tracer, lead-212, is radiochemically purified from thorium nitrate and is used for chemical yield determination. Food sample dissolution involves freeze drying and wet ashing to minimise contamination and eliminate volatilisation. The stable lead is determined spectrophotometrically as the dithizone complex at 510 mµ. The chemical recovery for analysis is 94 per cent., and the precision of analysis is better than 10 per cent.

Dosage du cadmium dans le nitrate de thorium par chronoamperometrie lineaire avec redissolution anodique

Linear chronoamperometry by anodic stripping has been applied to the determination of cadmium in solutions of thorium nitrate with K 2CO 3 or KCl-HCl as supporting electrolyte. The effect of supporting electrolyte concentration on the oxidation current is discussed.

Crystal structure of thorium nitrate pentahydrate by neutron diffraction

Crystal structure of thorium nitrate pentahydrate by neutron diffraction

Crystal structure of thorium nitrate pentahydrate by X-ray diffraction

Crystal structure of thorium nitrate pentahydrate by X-ray diffraction

The Relation between Ultrasonic Velocity and Viscosity in Aqueous Solutions of Electrolytes

Abstract From the experimental data on the ultrasonic velocity and viscosity of thorium nitrate, lanthanum acetate and lanthanum chloride, it has been found that the product of adiabatic compressibility and viscosity is fairly constant over the concentration range studied. From those data the relation between ultrasonic velocity and viscosity has been derived which can explain the variation in sound velocity with the concentration.

Studies on the formation of complex compounds between Uranyl Nitrate and transitional metal Nitrate. The system: Th(No3)4UO2(No3)2H2O

AbstractDetermination of conductance, pH, Spectrophotometry, and Refractive‐Index measurements of a series of mixed solutions of uranyl nitrate and thorium nitrate, indicate the existence of one definite complex‐compound in the solution namely Monovariation method of NNYAR and PANDE (1), has been followed in the preparation of the solution and in the investigation of properties. Aqueous solution of the uranyl nitrate and thorium nitrate were prepared in such a way that the concentration of uranyl nitrate was kept constant, while that of thorium nitrate was varied systematically, and the physico‐chemical properties recorded. When the values are plotted against the concentration of thorium nitrate curves are obtained with the specific breaks. The kink occurs at exact stoichiometric ratio of the concentrations corresponding to the compound noted above.

Conductometric end-point detection in the titration of fluoride and fluosilicic acid with thorium nitrate

Conductometric end-point detection in the titration of fluoride and fluosilicic acid with thorium nitrate

The polarography of molybdenum, titanium and niobium in solutions of organic acids

Further work on the polarographic reduction of molybdenum(VI), niobium(V) and titanium(IV) in base electrolytes containing organic acids is reported. A base electrolyte of 0.5 M citric acid-0.025 M sulphuric acid-0.05 M thorium nitrate proved suitable for the determination of molybdenum and titanium in the presence of niobium, tantalum, tungsten and zirconium. A direct polarographic method using this base electrolyte is described for the determination of molybdenum in a niobium base alloy.

Chemical Analysis of Bromine Trifluoride

The chemical analysis of bromine trifluoride (BrF3) was studied with the view to establishing a method for determining the purity of this substance, as attained by vacuum distillation. The sample bromine trifluoride was hydrolyzed in NaOH solution. The fluorine in the bromine trifluoride was converted to fluoride (F-) by the hydrolysis, and could thus be determined by thorium nitrate titration(1). The bromine in the bromine trifluoride was converted to bromide (Br-), hypobromite (BrO-) and bromate (BrO- 3), and was determined by the Mohr method, after reducing the BrO- and BrO- 3 to Br- with hydrazine hydrate (H2NNH2-H2O). A value of 2.97±0.03 wes obtained as ratio of fluorine to bromine for purified bromine trifluoride, and 2.84 for unpurified bromine trifluoride. Prior to analyzing the sample bromine trifluoride the conditions for reducing BrO- 3 to Br- by hydrazine hydrate were studied, using KBrO3 solution as sample. It was found that the alkalinity of the sample solution and the reduction temperature...

The determination of fluorine or phosphorus in organic compounds by a micro-titrimetric method

A method is described for determining fluorine or phosphorus in organic compounds synthesised for medical research. After combustion of the compound in an oxygen flask and absorption of the decomposition products in water, the contents are diluted with isopropanol, and titrated with thorium nitrate solution with a Solochrome cyanine R screened indicator. The addition of buffers is unnecessary. The removal of elements that interfere in the titration of fluorine is also described.

Chemical Analysis of Bromine Trifluoride

The chemical analysis of bromine trifluoride (BrF3) was studied with the view to establishing a method for determining the purity of this substance, as attained by vacuum distillation. The sample bromine trifluoride was hydrolyzed in NaOH solution. The fluorine in the bromine trifluoride was converted to fluoride (F-) by the hydrolysis, and could thus be determined by thorium nitrate titration(1). The bromine in the bromine trifluoride was converted to bromide (Br-), hypobromite (BrO-) and bromate (BrO- 3), and was determined by the Mohr method, after reducing the BrO- and BrO- 3 to Br- with hydrazine hydrate (H2NNH2-H2O). A value of 2.97±0.03 wes obtained as ratio of fluorine to bromine for purified bromine trifluoride, and 2.84 for unpurified bromine trifluoride. Prior to analyzing the sample bromine trifluoride the conditions for reducing BrO- 3 to Br- by hydrazine hydrate were studied, using KBrO3 solution as sample. It was found that the alkalinity of the sample solution and the reduction temperature had considerable influence on the reduction.