Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Sodium Formate 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 Formate 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, Insoluble Matter, Chloride, Sulfate, Calcium, Iron, and Heavy Metals.
HCOONa
Formula Wt 68.01
CAS No. 141-53-7
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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white solid precipitant for noble metals melting point, 253 °C soluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% HCOONa Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.005% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.001% Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . 0.001% Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 5 ppm Heavy metals (as Pb) . . . . . . . . . . . . . . . . . . 5 ppm
© 2017 American Chemical Society
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ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4348 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay
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(By titration of reducing power). Weigh accurately about 0.88 g, transfer to a 250 mL volumetric flask, dissolve with 50 mL of water, dilute with water to volume, and mix thoroughly. To 25.0 mL of this solution, in a 250 mL glass-stoppered flask, add 3 mL of 10% sodium hydroxide reagent solution and 50.0 mL of 0.1 N potassium permanganate volumetric solution. Heat on a hot plate (~100 °C) for 20 min, and then cool completely to room temperature. Add 4 g of potassium iodide crystals, mix, and add 5 mL of 25% sulfuric acid reagent solution. Titrate the liberated iodine, representing the excess permanganate, with 0.1 N sodium thiosulfate volumetric solution, using 5 mL of starch indicator solution near the end point. Run a blank on 25 mL of water with the same quantities of permanganate and other reagents, in the same manner as the sample. One milliliter of 0.1 N potassium permanganate consumed corresponds to 0.003401 g of HCOONa.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 20 g dissolved in 200 mL of water.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Use 1.0 g.
Sulfate [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 1]. Use 5.0 g of sample. Allow 30 min for turbidity to form.
Calcium and Iron (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium and Iron
S a m p l e S t o c k S o l u t i o n . Ignite 20.0 g of sample in a platinum crucible at 600 °C. Dissolve the residue in 10 mL of 20% hydrochloric acid, dilute with water to 50 mL, and filter. Dilute to the mark with water in a 100 mL volumetric flask (1 mL = 0.20 g).
For the Determination of Calcium and Iron
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
0.40
0.02; 0.04
N/A
No
Fe
248.3
4.0
0.02; 0.04
A/A
Yes
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
B
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4348 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Heavy Metals
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[Part 2: Colorimetry and Turbidimetry; Heavy Metals (as Lead); Procedure for Heavy Metals, Method 1]. Substitute glacial acetic acid for 1 N acetic acid to adjust pH. Dissolve 6.0 g in water, and dilute with water to 30 mL. Use 25 mL to prepare the sample solution, and use the remaining 5.0 mL to prepare the control solution.
© 2017 American Chemical Society
C
ACS Reagent Chemicals ACS Reagent Chemicals; American Chemical Society: Washington, DC, 2017.
DOI:10.1021/acsreagents.4348 ACS Reagent Chemicals, Part 4
