Lanthanum nitrate

The most popular device for fluoride analysis is the ion-selective electrode (see Electro analytical techniques). Analysis usiag the electrode is rapid and this is especially useful for dilute solutions and water analysis. Because the electrode responds only to free fluoride ion, care must be taken to convert complexed fluoride ions to free fluoride to obtain the total fluoride value (8). The fluoride electrode also can be used as an end poiat detector ia titration of fluoride usiag lanthanum nitrate [10099-59-9]. Often volumetric analysis by titration with thorium nitrate [13823-29-5] or lanthanum nitrate is the method of choice. The fluoride is preferably steam distilled from perchloric or sulfuric acid to prevent iaterference (9,10). Fusion with a sodium carbonate—sodium hydroxide mixture or sodium maybe required if the samples are covalent or iasoluble. 

Sodium fluoroborate [13755-29-8] M 109.8, m 384 , d 2.47, pK -4.9 (for fluoroboric acid H30 BF4 ). Crystd from hot water (50mL/g) by cooling to 0 . Alternatively, purified from insoluble material by dissolving in a minimum amount of water, then fluoride ion was removed by adding cone lanthanum nitrate in excess. After removing lanthanum fluoride by centrifugation, the supernatant was passed... 

The catalyst was prepared by impregnating porous alumina particles with a solution of nickel and lanthanum nitrates. The metal loading was 20 w1% for nickel and 10 wt% for lanthanum oxide. The catalyst particles were A group particles [8], whereas they were not classified as the AA oup [9]. The average particle diameter was 120 pm, and the bed density was 1.09 kg m . The minimum fluidization velocity was 9.6 mm s. The settled bed height was around 400 mm. The superficial gas velocity was 40-60 mm s. The reaction rate was controlled by changing the reaction temperature. 

A number of new conditions and catalysts have been used for the synthesis of quinazolinones 50 from anthranilic acids, amines and ortho esters, including bismuth trifluoroacetate with an ionic liquid <06TL3561>, lanthanum nitrate or tosic acid under solvent-free conditions at room temperature <06TL4381> and Nafion-H <06SL2507>. 

In usual practice, the titrant (e.g., Lanthanum Nitrate) is added in large amounts at the initial stage as the end-point is approached, which is marked by distinct larger potential changes per addition, the subsequent increments are made smaller to the tune of 0.1 ml for each addition. 

The apparent failure of trivalent and tetravalent cations to enter plants could result from the interaction of the cations with the phospholipids of the cell membranes. Evidence for such interactions is provided by the use of lanthanum nitrate as a stain for cell membranes (143) while thorium (IV) has been shown to form stable complexes with phospholipid micelles (144). However, it is possible that some plant species may possess ionophores specific to trivalent cations. Thomas (145) has shown that trees such as mockernut hickory can accumulate lanthanides. The proof of the existence of such ionophores in these trees may facilitate the development of safeguards to ensure that the actinides are not readily transported from soil to plants. 

Lanthanum fluoride may be precipitated by adding hydrofluoric acid to an aqueous solution of lanthanum nitrate or chloride ... 

Formula La(N03)3 6H20 MW 433.01 stable as hexahydrate Synonym lanthanum nitrate hexahydrate... 

To about 15 mg in a test-tube, add 3 drops of phosphoric acid and close the tube with a stopper through which passes a smaller test-tube filled with water, and on the outside of which hangs a drop of lanthanum nitrate solution. Heat in a water-bath for 5 minutes (or if necessary bring slowly to the boil over a flame). Mix the drop of lanthanum nitrate solution with 1 drop of 0.02 N iodine on a white tile, and place 1 drop of dilute ammonia solution at the edge of the mixture. A blue color slowly appears at the junction of the two liquids indicating the presence of an acetyl group. 

The apparent slow atomization of some elements may be caused by carbide formation. Rapid heating and a reproducible surface (e.g. a pyrolytic surface) help reduce this problem, as does coating of the tube (e.g. with lanthanum, using lanthanum nitrate solution), and the use of metallic tubes or boats. 

Lanthanum Triazide, La(Ns)j, mw 222.97, N37-25 S, Curtius and Darapsky prepd the basic salt, Lanthanum Hydroxyazide, La (OH)(NjVl%HaO, by boiling a soln of lanthanum nitrate and sodium azide. The white slimy mass of basic lanthanum azide was obtained either on evapg the mixed soln in vacuo or on treating it with a mixt of ale eth. No props of the product were reported nor were there any addnt refs found in which any attempts were made to prepare and isolate the lanthanum azide... 

There has been recent interest in lanthanide complexes of ligands of the type (21). These are in some sense nitrogen analogues of the crown ethers. As Schiff bases, their lanthanide complexes may be synthesized by a template condensation, for example from 2,6-diacetylpyridine, 1,2-diaminoethane and lanthanum nitrate. These components react in alcohols to give [La(N03)3L], where the aza-crown L = (21 R = Me). This compound has a structure (Figure 6), quite analogous to that of [La(N03)3(18-crown-6)], in which La—N... 

Acetates may be detected by formation of foul-smelling cacodyl (poisonous) on heating with dry arsenic tiioxide. Other tests for acetate are the lanthanum nitrate test in which a blue or bluish-brown ring forms... 

T. Curtius and A. Darapsky prepared a basic salt, lanthanum hydroxyazide, La(0H)(N3)2l H20, by boiling a soln. of lanthanum nitrate and sodium azide. The white, slimy mass of basic lanthanum azide is obtained by evaporating the mixed soln. in vacuo, or by treatment of the soln. with a mixture of alcohol and ether. They also made rose-coloured didymium hydroxyazide, Dy(OH)(N3)2, by evaporating a soln. of didymium carbonate in hydrazoic acid. Freshly precipitated yttrium hydroxide dissolves in hydrazoic acid, forming a soluble yttrium hydroxyazide boiling a soln. of yttrium sulphate and sodium azide gives a precipitate of yttrium hydroxide. L. M. Dennis found that zirconium hydroxide is precipitated when a soln. of zirconium salt is treated with potassium azide. 

Ciampolini, M., Dapporto, P., and Nardi, N. (1979) Structure and properties of some lanthanoid(III) perchlorates with the cryptand 4,7,13,16,21,24-hexaoxa-l,10-diazabicyclo[8.8.8]hexacosane, Dalton Trans, 974-977 Hart, F. A., Hursthouse, M. B., Abdul Malik, K. M., and Moorhouse, S. (1978) X-ray crystal structure of a cryptate complex of lanthanum nitrate, Chem. Commun. 549-50. 

From this figure it can be seen that as the surface coverage increases so the amount of lanthanum nitrate required to produce coagulation increases until once a monolayer has been formed coagulation could not be produced even with 0.3 mol dm 3 lanthanum nitrate using a 600 X diameter particle. However, the protective action was particle size dependent and C12E6 was less effective with a particle of diameter 0.37 ym. 

Lanthanum nitrate, analysis of anhydrous, 5 41 Lead (IV) acetate, 1 47 Lead(II) 0,0 -diethyl dithiophos-phate, 6 142 Lead (IV) oxide, 1 45 Lead(II) thiocyanate, 1 85 Lithium amide, 2 135 Lithium carbonate, formation of, from lithium hydroperoxide 1-hydrate, 5 3 purification of, 1 1 Lithium chloride, anhydrous, 6 154 Lithium hydroperoxide 1-hydrate, 5 1... 

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