Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Sodium Azide Part 4, Monographs for Reagent Chemicals: General Descriptions, Specifications, and Tests eISBN: 9780841230460 Tom Tyner Chair, ACS Committee on Analytical Reagents James Francis Secretary, ACS Committee on Analytical Reagents
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ABSTRACT This monograph for Sodium Azide provides, in addition to common physical constants, a general description including typical appearance, applications, and aqueous solubility. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Assay, Insoluble Matter, Loss on Drying, and Titrable Base.
NaN3
Formula Wt 65.01
CAS No. 26628-22-8
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . colorless solid Applications . . . . . . . . . . . . . . . . . . . . . . . . reagent for chromium in water; reagent for metals Aqueous solubility . . . . . . . . . . . . . . . . . . . . highly soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% NaN3 Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.05% Loss on drying . . . . . . . . . . . . . . . . . . . . . . 0.1% Titrable base . . . . . . . . . . . . . . . . . . . . . . . 0.05 meq/g
TESTS Assay (By oxidation–reduction titrimetry). Weigh accurately 0.25 g of sample, and dissolve in 50 mL of water. In a fume hood, add 50.0 mL of 0.1 N ceric ammonium sulfate volumetric solution with stirring (nitrogen is evolved). Add 2 drops of nitric acid and 3 drops of 0.025 M ferroin indicator solution, and rinse the sides of the flask with water. Stir for 5 min. The sample can now be removed from the hood, and the excess ceric ammonium sulfate titrated with freshly standardized 0.1 N ferrous
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4329 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
ammonium sulfate volumetric solution. Add 0.25 mL of sulfuric acid just before the end point. The color changes from yellow to light green to an orange-red end point. Perform a blank titration on 50.0 mL of ceric ammonium sulfate. One milliliter of 0.1 N ceric ammonium sulfate consumed corresponds to 0.006501 g of NaN3.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Dissolve 2.0 g in 200 mL of water.
Downloaded by CORNELL UNIV on May 24, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4329
Loss on Drying [Part 2: Gravimetric Methods; Loss on Drying]. Weigh accurately 1.0 g, and dry at 105 °C to constant weight.
Titrable Base To 50 mL of water, add 0.15 mL of phenolphthalein indicator solution, and neutralize the solution using 0.01 N sodium hydroxide. Add 0.2 g of sample, and dissolve. If a pink color persists, not more than 1.0 mL of 0.01 N hydrochloric acid should be required to discharge the color.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4329 ACS Reagent Chemicals, Part 4
