Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Picric Acid (2,4,6-Trinitrophenol)
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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
ABSTRACT This monograph for Picric Acid provides, in addition to common physical constants, a general description including typical appearance, applications, aqueous solubility, and pKa. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Water, Melting Point (Dried), Insoluble, Resinous Matter, Insoluble in Toluene, and Sulfate. Special caution is advised for the handling or testing of this substance.
(NO2)3C6H2OH
Formula Wt 229.11
CAS No. 88-89-1
C a u t i o n : Trinitrophenol explodes when heated rapidly or when subjected to percussion. For safety in transportation, trinitrophenol is usually mixed with a minimum of 30% water.
GENERAL DESCRIPTION Typical appearance Applications . . . . . Aqueous solubility . pKa . . . . . . . . . .
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© 2017 American Chemical Society
pale yellow solid preparation of organic derivatives for identification 1 g in 100 mL 0.4
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4273 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
SPECIFICATIONS Water (H2O) . . . . . . . . . . . . . . . . . . . . . . . . ≥30% Melting point (dried) . . . . . . . . . . . . . . . . . . 121–123 °C
Maximum Allowable Insoluble and resinous matter . . . . . . . . . . . . 0.01% Insoluble in toluene . . . . . . . . . . . . . . . . . . . 0.1% Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . 0.1%
Downloaded by CORNELL UNIV on May 23, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4273
TESTS Water Weigh accurately about 1.0 g, and dissolve in 200 mL of water. Titrate with 0.1 N sodium hydroxide, using 0.15 mL of phenolphthalein indicator solution. One milliliter of 0.1 N sodium hydroxide corresponds to 0.02291 g of (NO2)3C6H2OH.
Subtract the percent of picric acid from 100% to determine the water content.
Melting Point (Dried) Carefully transfer a small amount of dried sample (prepared in the test for insoluble in toluene) to a capillary tube, and run the melting point, using an oil immersion bath.
Insoluble and Resinous Matter Dissolve a sample equivalent to 10 g on the dry basis in 500 mL of water, add 1 mL of sulfuric acid, and digest on a hot plate (~100 °C) for 1 h. Filter through a tared, preconditioned filtering crucible, wash thoroughly, dry at 105 °C, and weigh. No resinous material should be apparent in the crucible.
Insoluble in Toluene Dry 5–10 g at 70 °C and dissolve 4.0 g of the dried sample in 100 mL of warm toluene. (Note: Add water to the remaining dried sample before discarding it.) Filter off any insoluble material using a tared, preconditioned filtering crucible, wash thoroughly with warm toluene, and dry at 105 °C.
Sulfate [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 2]. Dissolve 0.5 g in 100 mL of water. Take 10 mL of this solution, and add 25 mL of nitric acid. Allow 30 min for turbidity to form.
© 2017 American Chemical Society
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4273 ACS Reagent Chemicals, Part 4
