Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Lead Subacetate 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 Lead Subacetate 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: Basic Lead, Loss on Drying, Insoluble in Dilute Acetic Acid, Insoluble in Water, Chloride, Nitrate, Calcium, Copper, Iron, Potassium, and Sodium.
Pb(C2H3O2)2 • 2Pb(OH)2
Formula Wt 807.70
CAS No. 1335-32-6
GENERAL DESCRIPTION Typical appearance . . . . . . . . . . . . . . . . . . . white solid Applications . . . . . . . . . . . . . . . . . . . . . . . . analysis of sugars Aqueous solubility . . . . . . . . . . . . . . . . . . . . soluble in 16 parts of cold water with alkaline reaction
SPECIFICATIONS Basic lead (PbO) . . . . . . . . . . . . . . . . . . . . . ≥33.0% Maximum Allowable Loss on drying . . . . . . . . . . . . . . . . . . . . . . 1.5% Insoluble in dilute acetic acid . . . . . . . . . . . . 0.02% Insoluble in water . . . . . . . . . . . . . . . . . . . . 1.0% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.003% Nitrate (NO3) . . . . . . . . . . . . . . . . . . . . . . . 0.003% Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 0.01% Copper (Cu) . . . . . . . . . . . . . . . . . . . . . . . . 0.002% Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.002% Potassium (K) . . . . . . . . . . . . . . . . . . . . . . . 0.02% Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.05%
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4193 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Basic Lead (By indirect acidimetry). Weigh accurately about 5 g of sample, and dissolve in 100 mL of carbon dioxide-free water in a 500 mL volumetric flask. Add 50.0 mL of 1 N acetic acid volumetric solution and 100 mL of carbon dioxide-free 3% solution of sodium oxalate. Mix thoroughly, dilute to volume with carbon dioxide-free water, and allow the precipitate to settle. Decant and titrate 100.0 mL of the clear supernatant liquid with 1 N sodium hydroxide volumetric solution, using 0.15 mL of phenolphthalein indicator solution. Each milliliter of 1 N acetic acid consumed is equivalent to 0.1116 g of PbO.
Loss on Drying Weigh accurately about 0.5 g in a tared, preconditioned dish or crucible, and dry at 105 °C for 2 h. Cool, and reweigh.
Insoluble in Dilute Acetic Acid Dissolve 5.0 g in 100 mL of dilute acetic acid (1:19), warming if necessary to effect complete dissolution. Filter through a tared, preconditioned filtering crucible, wash with dilute acetic acid (1:19) until the washings are no longer darkened by hydrogen sulfide, and dry at 105 °C.
Insoluble in Water Agitate 1.0 g, just until dissolved, in a small stoppered flask with 50 mL of carbon dioxide-free water, and filter at once through a tared, preconditioned filtering crucible. Wash with carbon dioxide-free water, and dry at 105 °C.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Dissolve 1.0 g in 30 mL of dilute nitric acid (1:9). Use 10 mL of this solution.
Nitrate [Part 2: Colorimetry and Turbidimetry; Nitrate; Procedure for Nitrate, Method 1 (Brucine Sulfate)].
For the Determination of Nitrate
S a m p l e S o l u t i o n A . Suspend 0.50 g in 3 mL of water. Dilute to 50 mL with brucine sulfate reagent solution. C o n t r o l S o l u t i o n B . Suspend 0.50 g in 1.5 mL of water and 1.5 mL of nitrate ion (NO3) standard solution. Dilute to 50 mL with brucine sulfate reagent solution. B l a n k S o l u t i o n C . Use 50 mL of brucine sulfate reagent solution.
Heat sample solution A, control solution B, and blank solution C in a preheated (boiling) water bath until the lead subacetate in A and B is dissolved, and then heat for 10 min more. Cool rapidly in an ice bath to room temperature, centrifuge sample solution A and control solution B for 10 min, and decant the liquids into 200 mm test tubes. The absorbance [Part 2: Colorimetry and Turbidimetry; Nitrate; Procedure for Nitrate, Method 1 (Brucine Sulfate)] of sample solution A should not exceed that of control solution B.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4193 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Calcium, Copper, Iron, Potassium, and Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
For the Determination of Calcium, Copper, Iron, Potassium, and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve 20.0 g of sample in a mixture of 50 mL of water and 10 mL of nitric acid, warming to achieve complete dissolution. Cool to room temperature, transfer to a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.2 g).
For the Determination of Calcium, Copper, Iron, Potassium, and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
1.0
0.05; 0.10
N/A
No
Cu
324.8
1.0
0.02; 0.04
A/A
Yes
Fe
248.3
4.0
0.08; 0.16
A/A
Yes
K
766.5
0.20
0.02; 0.04
A/A
No
Na
589.0
0.04
0.01; 0.02
A/A
No
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4193 ACS Reagent Chemicals, Part 4
