Page 260 - Demo

Safety Reference
Flinn Method #27h, continued
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FLINN METHOD
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Dissolve any leftover barium salt in a minimum amount of water. (Barium carbonate and barium peroxide are not soluble in water, so just suspend them in a tenfold excess of their weight in water.)
Barium Compound
H2O
3 M H2SO4
#27j Halogenated Solvents
Halogenated solvents are toxic compounds. They are immiscible with water and require licensed hazardous waste disposal (see Flinn Disposal Method #26c). Most halogenated solvents are characteristic (toxic) or U-Listed hazardous wastes.
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Add 3 M sulfuric acid to the solution while stirring until the precipitation of barium sulfate appears to be complete. Add at least a twofold molar excess of sulfuric acid.
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Allow the precipitate to settle, and decant off the supernatant liquid or filter off the precipitate.
REFERENCES
The disposal procedures listed in this section are obtained from the following reliable and highly regarded sources:
Armour, Margaret-Ann. Hazardous Laboratory Chemicals Disposal Guide, 3rd Edition. Boca Raton, FL: CRC Press, Lewis Publishers, 2003.
National Research Council. Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards. Washington, D.C.: National Academies Press, 2011.
ACS Task Force in Laboratory Waste Management. Laboratory Waste Management: A Guidebook. Washington, D.C.: American Chemical Society, 2012.
Lunn, George and Eric B. Sansone. Destruction of Hazardous Chemicals in the Laboratory, 3rd Edition. New York: John Wiley and Sons, 2012.
“Little Known But Allowable Ways to Deal with Hazardous Waste.” EPA Publication 233-B-00-002. May 2000, accessed August 2015. http://nepis.epa.gov.
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pH Paper
The liquid will be acidic; using pH indicator paper, neutral- ize it with sodium carbonate. Check that the neutral solu- tion does not contain residual barium and rinse it down the drain with excess water.
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Na2CO3
Please...Read the Narratives
Important narratives precede these specific chemical disposal methods! Please read each narrative carefully! Do not use these procedures if you are not comfortable with the chemistry. Do not use these procedures without first consulting with your local government regulatory officials. These procedures may not be used in some jurisdictions. All procedures involve some hazards and risks. Once again...read the narratives that precede these specific chemical disposal methods.
Allow the precipitate to dry and package it for licensed hazardous waste disposal.
Hazardous Waste