Metals flame testing

If an appreciable amount of residue remains, note its colour. Add a few drops of water and test the solution (or suspension) with htmus or with Universal indicator paper. Then add a httle dilute hydrochloric acid and observe whether efiervesceiice occurs and the residue dissolves. Apply a flame test with a platinum wire on the hydrochloric acid solution to determine the metal present. (In rare cases, it may be necessary to subject a solution of the residue to the methods of qualitative inorganic analysis to identify the metal or metals present.) If the flame test indicates sodium, repeat the ignition of the substance on platinum foil. 

AMD 1 Eire hazard testing. Part 2 Test methods. Needle-flame test (AMD 9176J dated 15 November 1996. Previously known as BS 6458 Section 2.2 1993 Eire hazard testing. Terminology concerning fire tests. Superseded BS 6458 Part 1 1990 Elammability of solid non-metallic materials when exposed to flame sources - List of test methods. Superseded BS 6334 1983... 

The alkali metal cations are identified by flame tests (Figure C). 

Identifying Metals emit characteristic colors in flame tests. Copper emits a blue-green light. Do your observations in step 12 confirm the presence of copper in the filtrate collected in step 9 ... 

Because its outet valence electrons ate at a gteatet distance from its nuclei, potassium is more reactive than sodium or lithium. Even so, potassium and sodium are very similar in their chemical reactions. Due to potassiums high reactivity, it combines with many elements, particularly nonmetals. Like the other alkali metals in group 1, potassium is highly alkaline (caustic) with a relatively high pH value. When given the flame test, it produces a violet color. 

Bright, silvery-white metal face-centered cubic crystal structure (a = 0.5582 nm) at ordinary temperatures, transforming to body-centered cubic form (a= 0.4407) at 430°C density 1.54 g/cm at 20°C hardness 2 Mohs, 17 Brinnel (500 kg load) melts at 851°C vaporizes at 1,482°C electrical resistivity 3.43 and 4.60 microhm-cm at 0° and 20°C, respectively modulus of elasticity 3-4x10 psi mass magnetic susceptibility -i-1.10x10 cgs surface tension 255 dynes/cm brick-red color when introduced to flame (flame test) standard reduction potential E° = -2.87V... 

Strontium and all its compounds impart crimson red color in the flame test. The metal in trace concentrations can be analyzed by various instrumental methods that include flame-and fumace-AA, ICP-AES, ICP/MS, x-ray fluorescence, and neutron activation analysis. 

Size and Duration of Flame Developed on Explosion (16-18) Burning of Propellants (18-20) Brisance by Metal plate Tests (110-11) Power by Trauzl Test (111-13) ... 

Flame Photometry. An analytical method suitable for qual and quant detn of about 70 elemcats, flame photometry is based on the classical flame tests for the alkali and alkaline-earth metals (Na yellow, K purple,... 

Lithium Sodium Potassium Flame tests of alkali metals... 

Qualitative chemistry is an area of chemistry concerned with identifying substances. In Activity 9.1 you will perform a qualitative analysis to detect the presence of certain ions that, in turn, may reveal an art forgery. The ions could come from paints that were not available at the time of the artwork. In this qualitative analysis, metal ions (cations) and nonmetal ions (anions) are reacted with solvents and with each other. Then the cations and anions present are identified by the products produced. In addition, flame tests and pH determinations are used to identify ions. Qualitative analysis is an engaging opportunity for you to develop experience with chemical change and review solubility principles. Nowadays, however, most of the time a chemist analyzes a substance to detect ion content using quantitative analytical computerized instruments. 

Another qualitative analysis technique is a flame test. A dissolved ionic compound is placed in a flame. Table 9.4 lists the flame colours associated with several ions. Notice that all the ions are metallic. The flame test is only useful for identifying metallic ions in aqueous solution. 

We can now return to the flame tests. Compounds of certain metals are volatilized in the non-luminous Bunsen flame and impart characteristic colours to the flame. The chlorides are among the most volatile compounds, and these are prepared in situ by mixing the compound with a little concentrated hydrochloric acid before carrying out the tests. The procedure is as follows. A thin... 

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. 

Separation. In order to separate lithium from the other alkali metals, they are all converted into the chlorides (by evaporation with concentrated hydrochloric acid, if necessary), evaporated to dryness, and the residue extracted with absolute alcohol which dissolves the lithium chloride only. Better solvents are dry dioxan (diethylene dioxide, C4H802) and dry acetone. Upon evaporation of the extract, the residue of lithium chloride is (a) subjected to the flame test, and (b) precipitated as the phosphate after dissolution in water and adding sodium hydroxide solution. 

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 increased ionization energies of the heavier transition metals should not be unexpected by anyone who has had a modicum of laboratory experience with any of these elements. Although none of the coinage metals is very reactive, gold has a well-deserved reputation for being less reactive than copper or silver iron, cobalt, and nickel rust and corrode, but osmium, indium, and platinum are noble and unreaclive and therefore are used in jewelry platinum wires are the material of choice fior flame tests without contamination and one generates hydrogen with zinc and simple adds, not with mercury. 

Simple flame tests can be carried out on solid samples. Place a little of the solid on a watch-glass and moisten with a drop of concentrated hydrochloric acid. The purpose of the hydrochloric acid is to produce metal chlorides which are volatile at the temperature of the Bunsen burner. 

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 ... 

Identify a set of flame-test color standards for selected metal ions. 

Relate the colors of a flame test to the behavior of excited electrons in a metal ion. 

To determine what metal is contained in the barrels behind the Benettis house, you must first perform flame tests with a variety of standard solutions of different metal compounds. Then you will perform a flame test with the unknown sample from the site to see if it matches any of the solutions you ve used as standards. Be sure to keep your equipment very clean, and perform multiple trials to check your work. 

Organizing data Examine your data table, and create a summary of the flame test for each metal ion. 

Analyzing data Account for any differences in the individual trials for the flame tests for the metal ions. 

Identifying patterns For three of the metal ions tested, explain how the flame color you saw relates to the lines of color you saw when you looked through the spectroscope. 

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