Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Lead Monoxide (Lead(II) Oxide; Litharge) 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 Monoxide 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 in Dilute Acetic Acid, Chloride, Nitrate, Calcium, Copper, Iron, Potassium, Silver, and Sodium.
PbO
Formula Wt 223.20
CAS No. 1317-36-8
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
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yellow or orange solid assays of gold and silver ores melting point, 888 °C insoluble
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . ≥99.0% PbO Maximum Allowable Insoluble in dilute acetic acid . . . . . . . . . . . . 0.02% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.002% Nitrate (NO3) . . . . . . . . . . . . . . . . . . . . . . . 0.01% Calcium (Ca) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Copper (Cu) . . . . . . . . . . . . . . . . . . . . . . . . 0.005% Iron (Fe) . . . . . . . . . . . . . . . . . . . . . . . . . . 0.002% Potassium (K) . . . . . . . . . . . . . . . . . . . . . . . 0.005% Silver (Ag) . . . . . . . . . . . . . . . . . . . . . . . . . 5 ppm Sodium (Na) . . . . . . . . . . . . . . . . . . . . . . . . 0.02%
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4190 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
TESTS Assay (By complexometric titration of Pb). Weigh accurately about 0.8 g, transfer to a 400 mL beaker, and dissolve by warming with a mixture of 1 mL of acetic acid and 10 mL of water. After solution is complete, dilute to 250 mL with water and add 15 mL of hexamethylenetetramine reagent solution and 50 mg of xylenol orange indicator mixture. Titrate with 0.1 M EDTA volumetric solution to a color change of purple-red to lemon yellow. One milliliter of 0.1 M EDTA corresponds to 0.02232 g of PbO.
Insoluble in Dilute Acetic Acid Heat 5.0 g with a mixture of 50 mL of water and 15 mL of acetic acid until solution is complete. Filter through a tared, preconditioned sintered-glass crucible, wash thoroughly with hot water, dry at 105 °C for 1 h, cool, and weigh.
Chloride [Part 2: Colorimetry and Turbidimetry; Chloride]. Use 0.5 g.
Nitrate [Part 2: Colorimetry and Turbidimetry; Nitrate; Procedure for Nitrate, Method 1 (Brucine Sulfate)]. Dissolve 0.5 g in a mixture of 10 mL of water and 1 mL of acetic acid. Add 5 mL of 25% sulfuric acid reagent solution, mix well, and allow to stand for 15 min, mixing occasionally. Filter, wash with 5 mL of water, and dilute the filtrate to 25 mL.
For the Determination of Nitrate
S a m p l e S o l u t i o n A . Dilute 5.0 mL of the nitrate-test filtrate to 50 mL with brucine sulfate reagent solution. C o n t r o l S o l u t i o n B . To 5.0 mL of the nitrate-test filtrate, add 1.0 mL of nitrate ion (NO3) standard solution. Dilute to 50 mL with brucine sulfate reagent solution.
Continue with the procedure, starting with the preparation of blank solution C.
Calcium, Copper, Iron, Potassium, Silver, 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, Silver, and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve by warming 20.0 g of sample with a mixture of 50 mL of water and 20 mL of acetic acid. Cool to room temperature, transfer to a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.2 g).
© 2017 American Chemical Society
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DOI:10.1021/acsreagents.4190 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
For the Determination of Calcium, Copper, Iron, Potassium, Silver, and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
0.80
0.02; 0.04
N/A
No
Cu
324.8
0.80
0.02; 0.04
A/A
Yes
Fe
248.3
4.0
0.08; 0.16
A/A
Yes
K
766.5
0.80
0.02; 0.04
A/A
No
Ag
328.1
4.0
0.02; 0.04
A/A
Yes
Na
589.0
0.10
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.4190 ACS Reagent Chemicals, Part 4
