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Luminescent Compounds, i. e., Phosphors
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Submitted by: H. R. Tietzie, New Castle University College, New South Wales, Australia Checked by: David B Moss and Dale Dreisbach, Hiram College, Hiram, Ohio
STRONTIUM SULFIDE PHOSPHOR
Provide 10 g SrCOi, 10g roll sulfur, 0.0: g KCI, 0.05 g NaCI and 0.04 g MnCk 4H;O Thoroughly mix the above ingredients by grinding them together in a mortar. Fire the mixture for about ' l ahour at 800°C The resulting product has a yellow luminescence. CADMIUM CHLOROPHOSPHATE PHOSPHOR
Dissolve 27 g CdCO, in 30 ml cone HC1 and 40 ml distilled water, and filter. Mix the filtrate with 69 g CdHP04 and 2 6 g MnHP04, and dry the mixture slowly under a hood. Grind the mixture, and heat hour at 600°C Regsind and heat in a furnace for '1% for hour at 80O0C. This last operation should be repeated. After cooling, wash the mixture free from
C l with distilled water, and dry. The resulting product has a red luminescence. ALTERNATE METHOD
Suggested by: J . F. Ross and D. T. Hurd of Generay Electric Company Mix either 241 g CdNH4P04 H 2 0 or 400 g CdsPsO, with 46.5 g CdCO,, 31 g CdC12 and 6.6 g MnCOa(CdsPsOrcan be precipitated from CdCL and Na4P20, solutions MnCOa can be precipitated from MnCL and Na2COs solutions.) Pulverize to mix, and fire in furnace for 45 min. in covered boats or a tray a t 1000° The resulting phosphor is bright orange-yellow.
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A REACTION TUBE FOR SODIUM AND CHLORINE
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l of Chemical Education
January 3963
1 1
Submdted by: Robert Barnard, Montana State College, Bozeman Cher7.ed by: Roger Wheaton, Michigan State X-'uiversity,East Lansing
PREPARATION
DEMONSTRATION
Prepare several reaction tubes by bending 10 mm Pyrex tubing into slightly less than a "V" shape with each arm approximately 10-15 mm long Prepare cubes of sodium metal (under a hydrocarbon) which will slide into the reaction tube. Additional materials include: a source of chlorine gas, bunsen burner, and a sodium hydroxide trap. Clamp the reaction tube between two ring stands, connecting one end of the tube to the source of chlorine. Dry the sodium by pressing it between a piece of absorbent paper and drop it into the open end of the reaction tube. Shake the tube if necessary to place the sodium a t the bottom of the "V." Connect the open end of the tube to a sodium hydroxide trap.
The sodium may now be heated and will display a shiny metallic surface. Remove the heat and pass chlorine into the system (gently). The metal will react immediately. Intense heat and light will he generated. Shut off the flow of chlorine and disconnect the trap to prevent syphoning. The tube will break a t the area of reaction and white sodium chloride may be observed. REMARKS
(The original demonstration was suggested in "Experiments in General Chemistry" - hv Gaines. Woodriff. Binder, Johausson, C. V. Mosby Co., St. Louis, Mo.; "
1951.)
i
d of Chemical Education
.
January 1963
