https://epg.modot.org/index.php?title=106.3.2.56_TM-56,_Determination_of_Sodium_Metasilicate_(Na2SiO3)&feed=atom&action=history106.3.2.56 TM-56, Determination of Sodium Metasilicate (Na2SiO3) - Revision history2024-03-29T07:30:51ZRevision history for this page on the wikiMediaWiki 1.33.1https://epg.modot.org/index.php?title=106.3.2.56_TM-56,_Determination_of_Sodium_Metasilicate_(Na2SiO3)&diff=23441&oldid=prevSmithk: Per CM, article moved to conform with Sec 106. Old EPG 106.7.56 had no appreciable history and 635 hits2010-06-30T20:41:57Z<p>Per CM, article moved to conform with Sec 106. Old EPG 106.7.56 had no appreciable history and 635 hits</p>
<p><b>New page</b></p><div>This method determines the percent of anhydrous sodium metasilicate (Na<sub>2</sub>SiO<sub>3</sub>) in automotive antifreeze by Atomic Absorption Spectrophotometry.<br />
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==106.3.2.56.1 Reagents and Apparatus==<br />
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1) An Atomic Absorption Spectrophotometer.<br />
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2) Potassium Chloride (KCl), Reagent Grade.<br />
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3) Ethylene Glycol, Reagent Grade.<br />
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4) Silicon Standard Solution, 1000 ppm. This solution can be purchased from a number of sources.<br />
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==106.3.2.56.2 Preparation of Standard Solutions==<br />
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0,000 ppm Potassium Stock Solution: Weigh 19.068 g of dried, reagent grade KCl into a<br />
1000-mL volumetric flask, dissolve, and dilute to volume with distilled water.<br />
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152% Na<sub>2</sub>SiO<sub>3</sub> Standard: Pipette a 20-mL aliquot of 10,000 ppm K stock solution and a 7-mL aliquot of 1000 ppm Si standard solution into a 200-mL volumetric flask. Add 20.00 g of reagent grade ethylene glycol and dilute to volume with distilled water.<br />
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0.109% Na<sub>2</sub>SiO<sub>3</sub> Standard: Pipette a 20-mL aliquot of 10,000 ppm K stock solution and a 5-mL aliquot of 1000 ppm Si standard solution into a 200-mL volumetric flask. Add 20.00 g of reagent grade ethylene glycol and dilute to volume with distilled water.<br />
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Blank Solution: Pipette a 10-mL aliquot of 10,000 ppm K stock solution into a 100-mL volumetric flask. Add 10.00 g of reagent grade ethylene glycol and dilute to volume with distilled water.<br />
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==106.3.2.56.3 Procedure==<br />
Weigh, to the nearest 0.1 mg, 10 ± 0.05 g antifreeze into a 100-mL volumetric flask. Pipette a 10-mL aliquot of 10,000 ppm K stock solution into the volumetric flask and dilute to volume with distilled water.<br />
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Calibrate the instrument with the blank solution, the 0.109% Na<sub>2</sub>SiO<sub>3</sub> solution and the 0.152%<br />
Na<sub>2</sub>SiO<sub>3</sub> solution, then determine the concentration of the sample solution.<br />
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==106.3.2.56.4 Calculation and Report==<br />
The method of calculating the % sodium metasilicate will vary according to the make and model of instrument used.<br />
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Report the results to the nearest 0.01% Na<sub>2</sub>SiO<sub>3</sub> as follows:<br />
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:% Sodium Metasilicate (Na<sub>2</sub>SiO<sub>3</sub>), anhydrous<br />
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[[Category:106.3.2 Material Inspection Test Methods]]</div>Smithk