Color flame

Note that some of the metals frequently encountered in simple organic compounds give characteristic flame colorations Na, yellow K, lilac through blue glass Ca, brick-red Ba, apple-green Cu, bright blue-green. Ag and Pb, no characteristic flame. 

VFO works well in gas turbines. In a nine-month test program, the combustion properties of VFO were studied in a combustion test module. A gas turbine was also operated on VFO. The tests were conducted to study the combustion characteristics of VFO, the erosive and corrosive effects of VFO, and the operation of a gas turbine on VFO. The combustion tests were conducted on a combustion test module built from a GE Frame 5 combustion can and liner. The gas turbine tests were conducted on a Ford model 707 industrial gas turbine. Both the combustion module and gas turbine were used in the erosion and corrosion evaluation. The combustion tests showed the VFO to match natural gas in flame patterns, temperature profile, and flame color. The operation of the gas turbine revealed that the gas turbine not only operated well on VFO, but its performance was improved. The turbine inlet temperature was lower at a given output with VFO than with either natural gas or diesel fuel. This phenomenon is due to the increase in exhaust mass flow provided by the addition of steam in the diesel for the vaporization process. Following the tests, a thorough inspection was made of materials in the combustion module and on the gas turbine, which came into contact with the vaporized fuel or with the combustion gas. The inspection revealed no harmful effects on any of the components due to the use of VFO. 

All the alkali metals have characteristic flame colorations due to the ready excitation of the outermost electron, and this is the basis of their analytical determination by flame photometry or atomic absorption spectroscopy. The colours and principal emission (or absorption) wavelengths, X, are given below but it should be noted that these lines do not all refer to the same transition for example, the Na D-line doublet at 589.0, 589.6 nm arises from the 3s — 3p transition in Na atoms formed by reduction of Na+ in the flame, whereas the red line for lithium is associated with the short-lived species LiOH. 

Energy imd wnvelength. A copper wire held in a flame colors the flame green. The energy of the photons of this light can be calculated from its wavelength. 

The salts of Na, Ba and Sr, used as oxidants and to impart appropriate flame colors, are w soluble. Excessive moisture content (over 0.5%) is deleterious in terms of light intensity, color saturation and burning duration. BlkPdr, a widely used ignition source and flame transfer agent, absorbs moisture and deteriorates rapidly. Many instances of pyrot no-fire incidents have been found to be the result of such deterioration (Refs 10,18,21 38)... 

Ref 130, p 220) and by Great Britain (Vol 3, C498-R). These rockets utilized BlkPdr as proplnt, fuse (Ref 122) and as an expl. Up to the middle of the last century the history of pyrotechnics is the history of BlkPdr. Even now, as will be discussed in Section 7, large quantities of BlkPdr are used as an igniter. By the late 18 th century a new age in pyrotechnics commenced thru the synthesis of K chlorate (Vol 2, C190-R), the discovery of Fulminates (Vol 6, F216-R) and the identification of the minerals which would impart color to a flame. The discovery of electricity brought about pure chemicals and hence, better flame colors, new oxi-... 

Predicting If a sample of a potassium compound was heated in a Bunsen burner flame, would the flame color be yellow Explain. 

Strontium - the atomic number is 38 and the chemical symbol is Sr. The name derives from Strontian, a town in Scotland . The mineral strontianite is found in mines in Strontian. The element was discovered by the Scottish chemist and physician Thomas Charles Hope in 1792 observing the brilliant red flame color of strontium. It was first isolated by the English chemist Humphry Davy in 1808. 

Hydraulic fluids usually exhibit a consistent response of smoke color, flame color, autoignition temperature, and a whitish residue. 

B) Refer to the Flame Color chart found in CliffsAP Chemistty, 3rd Edition. 

The use of pyrotechnic mixtures for military purposes in rifles, rockets, and cannons developed simultaneously with the civilian applications such as fireworks. Progress in both areas followed advances in modern chemistry, as new compounds were isolated and synthesized and became available to the pyrotechnician. Berthollet s discovery of potassium chlorate in the 1780 s resulted in the ability to produce brilliant flame colors using pyrotechnic compositions, and color was added to the effects of sparks, noise, and motion previously available using potassium nitrate-based compositions. Chlorate -containing color-producing formulas were known by the 1830 s in some pyrotechnicians arsenals. 

Table 7.7 gives some data on flame temperatures obtained by Shimizu for oxidizer/shellac mixtures. Sodium oxalate was added to yield a yellow flame color and permit temperature measurement by the "line reversal" method [11]. 

The oxidizer s positive ion (cation) must not adversely affect the desired flame color. Sodium, for example, is an intense emitter of yellow light, and its presence can ruin attempts to generate red, green, and blue flames. 

Yellow flame color is achieved by atomic emission from sodium. The emission intensity at 589 nanometers increases as the reaction temperature is raised there is no molecular emitting species here to decompose. Ionization of sodium atoms to sodium ions will occur at very high temperatures, however, so even here there is an upper limit of temperature that must be avoided for maximum color quality. The emission spectrum of a yellow flare is shown in Figure 7.2. 

Analysis. Ca gives a brick-red flame coloration, indicating that various optical spectroscopies will be effective in its determination. Ca is quantitatively determined by colorimetry down to 100 ppb using murexide or o-cresolphthalein, by atomic absorption spectroscopy (AAS) to 20 ppb, to 1 ppb by electrothermal absorption spectroscopy (ETAS), to 0.01 ppb by inductively-coupled plasma emission spectroscopy (ICPES), and to 10 ppb by inductively-coupled plasma mass spectroscopy (ICPMS). A spot test for Ca which extends to 3 ppm is provided by glyoxal bis(2-hydroxyanil). 

Anaiysis. If a borate is treated with H2SO4 and methanol H3COH, methyl borate is produced. If a small amount of the mixture is introduced to a flame, a green flame color is produced. The test is sensitive to 20 ppm of B. Ba and Cu interfere, both of these also giving a green color. A spot test with curcumin will detect 5 ppm of B. Titration of H3BO3 in a mannitol solution... 

During the progress of burning, it is also advisable to observe the appearance of the flame (color, smoke etc) and its dimensions, ... 

Flame color depends on fuel composition. Gas often burns blue, but heavy fuel oil burns yellow. A yellow flame is caused by thermal cracking of the fuel. There is nothing wrong with a yellow flame it is the general shape of the flame which is important. If in doubt as to the right flame shape for a particular furnace, contact the burner manufacturer for details. 

Certain nitrogenous compounds, however, give a volatile cuprous cyanide in this test which produces a green flame coloration. The presence of halogen must therefore be confirmed by other tests. 

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