Monograph pubs.acs.org/doi/book/10.1021/acsreagents
4-(Methylamino)phenol Sulfate 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
Downloaded by CORNELL UNIV on May 26, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4224
ABSTRACT This monograph for 4-(Methylamino)phenol Sulfate provides, in addition to common physical constants, a general description including typical appearance, applications, change in state (approximate), 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, Residue after Ignition, and Suitability for Determination of Phosphate.
(CH3NHC6H4OH)2 • H2SO4 Formula Wt 344.38
CAS No. 55-55-0
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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solid; discolors in air determination of phosphate melting point, 260 °C, with decomposition soluble in 20 parts cold, 6 parts boiling water
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99.0–101.5% Residue after ignition. . . . . . . . . . . . . . . . . . ≤0.1% Suitability for determination of phosphate . . . . Passes test
© 2017 American Chemical Society
A
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4224 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay (By titration of reductive capacity). Weigh about 250 mg to the nearest 0.1 mg. Transfer to a 500 mL conical flask containing 100 mL of water and 10 mL of 0.1 N sulfuric acid. Dissolve, add 0.15 mL of 0.025 M ferroin indicator solution, and titrate with 0.1 N ceric ammonium sulfate volumetric solution to a light green color that persists for 15 s. One milliliter of 0.1 N ceric ammonium sulfate corresponds to 0.00861 g of (CH3NHC6H4OH)2 · H2SO4.
Downloaded by CORNELL UNIV on May 26, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4224
Residue after Ignition [Part 2: Gravimetric Methods; Residue after Ignition]. Ignite 5.0 g.
Suitability for Determination of Phosphate Dissolve 2.0 g in 100 mL of water. To 10 mL of this solution add 90 mL of water and 20 g of sodium bisulfite, dissolve, and mix. Transfer 1 mL of this solution to each of two solutions containing 25 mL of 0.5 N sulfuric acid and 1 mL of ammonium molybdate–sulfuric acid reagent solution. For the control, add 0.005 mg of phosphate ion (PO4) to one of the solutions. For the sample, use the remaining solution. Allow the solutions to stand at room temperature for 2 h. The control should turn perceptibly darker blue than the sample.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4224 ACS Reagent Chemicals, Part 4
