Zincon - American Chemical Society

verifying that a substance meets ACS Reagent Grade specifications including: Clarity of Solution and Suitability for. Complexometric Titration. O. OH...
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Monograph pubs.acs.org/doi/book/10.1021/acsreagents

Zincon (2-{[α-(2-Hydroxy-5-sulfophenylazo)-benzylidene]-hydrazino}-benzoic Acid Monosodium Salt)

Downloaded by CORNELL UNIV on May 15, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4430

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 Zincon provides, in addition to common physical constants, a general description including typical appearance and applications. The monograph also details the following specifications and corresponding tests for verifying that a substance meets ACS Reagent Grade specifications including: Clarity of Solution and Suitability for Complexometric Titration.

C20H15N4NaO6S (anhydrous) C20H15N4NaO6S• H2O (monohydrate)

Formula Wt 462.41

CAS No. 62625-22-3

Formula Wt 480.43

Note: This standard applies to both the anhydrous and monohydrate form of the indicator.

GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . purple solid Applications . . . . . . . . . . . . . . . . . . . . . . . . reagent for zinc, mercury, and copper

© 2017 American Chemical Society

A

ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.

DOI:10.1021/acsreagents.4430 ACS Reagent Chemicals, Part 4

ACS Reagent Chemicals

Monograph

pubs.acs.org/doi/book/10.1021/acsreagents

SPECIFICATIONS Clarity of solution . . . . . . . . . . . . . . . . . . . . Passes test Suitability for complexometric titration (Zn) . . . Passes test

TESTS Clarity of Solution Weigh 0.10 g, and dissolve in 100 mL of water. Not more than a faint trace of turbidity or insoluble matter should remain. Reserve the solution for the suitability for complexometric titration test.

Downloaded by CORNELL UNIV on May 15, 2017 | http://pubs.acs.org Publication Date (Web): February 28, 2017 | doi: 10.1021/acsreagents.4430

Suitability for Complexometric Titration To 25 mL of water, add 5 mL of pH 10 ammoniacal buffer solution and 0.10 mg of zinc ion. Add 0.5 mL of solution from the test for clarity of solution. A blue color develops. Add 0.10 mL of 0.1 M EDTA volumetric solution. The solution should become red.

© 2017 American Chemical Society

B

ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.

DOI:10.1021/acsreagents.4430 ACS Reagent Chemicals, Part 4