Flame test barium

HC1 and heat to boiling. If the soln is not clear, filter a portion thru a coarse filter paper, heat ca 100 ml of the clear soln to boiling, and add slowly 10 ml of 50% sulfuric acid. A white ppt indicates barium, which can be confirmed by the grn color obtd in a flame test. Filter and add to the cool filtrate 1 ml of coned HC1. A white ppt indicates the presence of lead... 

A table showing the colours imparted to the flame by salts of different metals is given in Section V.2(3). Carry out flame tests with the chlorides of sodium, potassium, calcium, strontium, and barium and record the colours you observe. Repeat the test with a mixture of sodium and potassium chlorides. The yellow colouration due to the sodium masks that of the potassium. View the flame through two thicknesses of cobalt glass the yellow sodium colour is absorbed and the potassium flame appears crimson. 

Dry test (flame colouration) Barium salts, when heated in the non-luminous Bunsen flame, impart a yellowish-green colour to the flame. Since most barium salts, with the exception of the chloride, are non-volatile, the platinum wire is moistened with concentrated hydrochloric acid before being dipped into the substance. The sulphate is first reduced to the sulphide in the reducing flame, then moistened with concentrated hydrochloric acid, and reintroduced into the flame. 

Heat upon a platinum wire in the reducing zone of the Bunsen flame This will reduce any sulphate present to sulphide (as already indicated in test 3). Upon moistening with dilute hydrochloric acid, the sulphide will be converted into the comparatively volatile chloride, and the usual flame test is applied. The presence of barium or of a mixture of strontium and barium will be indicated. 

Flame test. All thallium salts exhibit a characteristic green colouration when introduced into the colourless Bunsen flame. When examined through the spectroscope only one sharp line can be seen, at 535 nm, in contrast to barium, which exhibits several lines between 510 and 550 nm (cf. Fig. II.5 in Section II.2). 

When electrolytic iron foil is immersed in concentrated solutions of jodium or potassium hydroxide for several weeks, and, after thorough cleaning, allowed to corrode in distilled water, the latter gradually becomes contaminated with traces of sodium or potassium salts, the bresence of which can be detected by the spectroscope or by the usual Bunsen flame test.6 Similar results have been obtained with lithium lydroxide, barium hydroxide, and with ammonia.7 It appears probable hat the alkali penetrates in minute quantities into the metal between he ferrite crystals, possibly in consequence of a certain amount of borosity in the intercrystalline cement. This theory is supported by he fact that iron which has been soaked in alkali invariably pits ... 

The flame of an alcohol lamp looks almost colourless. Vhen a length of platinum v/ire which is dipped into a metal salt solutioh is put into the flame, the flame is coloured in the upper part by the wire. The colour is peculiar to the kind of the metal strontium colours the flame red, sodium yellow, barium pale green and copper blue. This is applied to the qualitative analysis of metal ions as the colour flame test. The emission of the coloured light is caused by atomic metal gas or a gas consisting of molecules of metal compound, and the process may be set out as follows ... 

If no precipitate appears, try the flame test by moistening the platinum wire in hydrochloric acid, dipping it into the salt to be tested and then into the flame. This will identify barium and potassium. Calcium and strontium, however, give flames so nearly alike that the confirmatory tests must always be applied. A yellow flame does not indicate sodium unless it persists ten or fifteen seconds, as sodium compounds are present as impurities in nearly all chemicals. Never report sodium unless the test for potassium has first been applied. Absence of flame test indicates arsenic or ammonium compounds. 

Three of the alkaline earth metals can be identified by flame tests. Calcium produces a scarlet color, while strontium produces a crimson color. Barium, which if present in a sample can mask the colors of both calcium and strontium, produces a yellow-green color. 

Carry out flame tests with the chlorides of sodium, potassium, calcium, strontium, and barium and record the colours you observe. Repeat the test... 

Various metals emit distinctive colors of visible light when heated to a high enough temperature (flame test). This is the basis for all fireworks, which use the salts of different metals such as strontium (red), barium (green), and copper (blue) to produce the beautiful colors. 

Flame tests can he used to identify three of the alkaline earth elements. The colors of both calcium and strontium can be masked by the presence of barium, which produces a green flame. 

FIGURE 7.14 Flame Tests (from left to right) for Sodium, Potassium, Lithium, and Barium We can identify elements by the characteristic color of the light they produce when heated. The colors derive from especially bright lines in their emission spectra. 

To test for positive ions, add 300 milligrams of the sample to be tested to water and mix. Filter the slurry and divide the filtered solution into two parts. To one part of the solution add a drop of a saturated sodium sulfate solution. Barium or strontium will come out of the solution as a white precipitate. A flame test on a platinum wire, using the part of the solution that was not treated with sodium sulfate, identifies barium or strontium. A green flame is produced by barium salts and a red flame is produced by strontium salts. To find the quantities of barium and strontium, add sodium sulfate until no more precipitation is formed. Filter and weigh the precipitate. The untreated aqueous solution may be flame tested for sodium and potassium. A yellow and violet flame is produced respectively, although the potassium test is diffcult. NH4 can be detected by an ammonia smell after the solution has been made basic with sodium hydroxide. 

Some of the Group 2 metals burn with characteristic flame colours. It is the 2+ ions formed in the reaction that cause the colours. We can test for calcium, strontium and barium in compounds using flame tests. A nichrome wire, cleaned with concentrated hydrochloric acid, is dipped into a sample of the salt to be tested and heated in a non-luminous Bunsen flame ... 

The atomic absorption characteristics of technetium have been investigated with a technetium hollow-cathode lamp as a spectral line source. The sensitivity for technetium in aqueous solution is 3.0 /ig/ml in a fuel-rich acetylene-air flame for the unresolved 2614.23-2615.87 A doublet under the optimum operating conditions. Only calcium, strontium, and barium cause severe technetium absorption suppression. Cationic interferences are eliminated by adding aluminum to the test solutions. The atomic absorption spectroscopy can be applied to the determination of technetium in uranium and its alloys and also successfully to the analysis of multicomponent samples. 

This zinc borate is a more effective flame retardant and smoke suppressant than barium metaborate (Busan 11M1).43 For example, in flexible PVC, a combination of antimony trioxide and the zinc borate results in much better fire test performances than the antimony trioxide and barium metaborate combination (Table 9.4). In contrast to flexible PVC, this zinc borate alone improves both fire retardancy and smoke suppression in rigid PVC.48... 

Barium. Before the routine use of AAS, Ba was analyzed by emission spectrograph or a KMnO spot test (13). Alkali and alkaline earth metals are analyzed in nitrous oxide/acetylene flames with ionization suppressants such as 1000 ppm Cs. For barium analysis by P CAM 173, background correction must be used whenever greater than 1000 ppm calcium is in the analyte solution. There are strong Ca(0H)2 absorptions and emission at 553.6 nm, which is the barium analytical line. 

Dry test (flame colouration) Volatile strontium compounds, especially the chloride, impart a characteristic carmine-red colour to the non-luminous Bunsen flame (see remarks under Barium). 

Test for borate Make a paste of the original substance with calcium fluoride and concentrated sulphuric acid. Hold some of this in a platinum loop just outside the base of the Bunsen flame. A green flame, due to boron trifluoride, indicates borates. Barium and copper do not interfere when the test is carried out in the above manner. 

When heated, barium compounds give off a pale yellow-green flame. This property is used as a test for barium. 

Characters and Tests.—Hard and greyish-white, very alkaline and corrosive. Does not deliquesce on exposure to the atmosphere. It imparts a yellow colour to flame, indicating the presence of sodium, and its solution in water, acidulated by nitric acid, should give only scanty white precipitates with argentum nitrate and barium chloride, showing the presence of traces only of chlorides and sulphates respectively. 

Characters and Tests. — Transparent oblique prisms has a saline and bitter taste effloresces on exposure to the air soluble in water. Heated in a porcelain crucible, it loses 55 9 per cent, of water. It imparts a yellow colour to flame, indicating the presence of sodium. With barium chloride its aqueous solution furnishes a white precipitate (barium sulphate) insoluble in nitric acid, showing that the salt is a sulphate. Its aqueous solution mixed with diluted hydrochloric acid gives no precipitate with platinic chloride, proving that it is neither a potassium nor an ammonium salt. 

Atomic spectrometric tests in air/acetylene flames a number of ions (like phosphate, sulphate, aluminium) decrease the emission and absorption signals of barium (and all of the alkaline earth metals). Adding an equal volume of a 25% solution of lanthanum chloride heptahydrate LaCl3 7H2O eliminates these interferences. Addition of lanthanum is not required if the nitrous oxide/acetylene flame is used. 

Atomic spectrometric tests the atomic spectrometric behaviour of strontium is very similar to that of barium (cf. Section 3.31, reaction 9). The use of lanthanum to eliminate interferences is recommended in air/ acetylene flames. 

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