Monograph pubs.acs.org/doi/book/10.1021/acsreagents
Cupric Nitrate Hydrate (Copper(II) Nitrate Hydrate) 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 Cupric Nitrate Hydrate 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, Lead, Nickel, Potassium, and Sodium.
Cu(NO3)2 · 2.5H2O Cu(NO3)2 · 3H2O
Formula Wt 232.59 Formula Wt 241.60
CAS No. 19004-19-4 CAS No. 10031-43-3
Note: This reagent is available containing either 2.5 or 3 molecules of water.
GENERAL DESCRIPTION Typical appearance . . . . . . . . Applications . . . . . . . . . . . . . Change in state (approximate) . Aqueous solubility . . . . . . . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
. . . .
hygroscopic blue solid preparation of copper standard solutions melting point, 112–115 °C 138 g in 100 mL at 0 °C
SPECIFICATIONS Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98.0–102.0% Cu(NO3)2 · 3H2O
Maximum Allowable Insoluble matter . . . . . . . . . . . . . . . . . . . . . 0.01% Chloride (Cl) . . . . . . . . . . . . . . . . . . . . . . . 0.002% Sulfate (SO4) . . . . . . . . . . . . . . . . . . . . . . . 0.01%
© 2017 American Chemical Society
A
DOI:10.1021/acsreagents.4105 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
Calcium (Ca) . Iron (Fe) . . . . Lead (Pb) . . . Nickel (Ni) . . . Potassium (K) . Sodium (Na) . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
. . . . . .
0.005% 0.005% 0.001% 0.01% 0.005% 0.01%
TESTS Assay (By iodometric titration of oxidative capacity of CuII). Weigh accurately about 1.0 g, dissolve in 5 mL of hydrochloric acid in a 100 mL beaker, and evaporate to dryness on a steam bath. Add 2 mL of sulfuric acid, and heat on a hot plate (~100 °C) to dense fumes of sulfur trioxide. Cool, add 5 mL of water and 5 mL of hydrochloric acid, and again evaporate to dryness on a hot plate (~100 °C). Dissolve the residue in water, transfer to a conical flask, and dilute with water to about 75 mL. Add 2 mL of glacial acetic acid and 3 g of potassium iodide. Titrate the liberated iodine with 0.1 N sodium thiosulfate volumetric solution, adding about 2 g of potassium thiocyanate and 3 mL of starch indicator solution near the end of the titration. Correct for a complete blank. One milliliter of 0.1 N sodium thiosulfate corresponds to 0.02326 g of Cu(NO3)2 · 2.5H2O or 0.02416 g of Cu(NO3)2 · 3H2O.
Insoluble Matter [Part 2: Gravimetric Methods; Insoluble Matter]. Use 10.0 g dissolved in 100 mL of dilute nitric acid (1:200). Omit heating.
Chloride Dissolve 0.50 g in 15 mL of dilute nitric acid (1:15), filter if necessary through a small chloride-free filter, and add 1 mL of silver nitrate reagent solution. Any turbidity should not exceed that produced by 0.01 mg of chloride ion (Cl) in an equal volume of solution containing the quantities of reagents used in the test. The comparison is best made by the general method for chloride in colored solution, [Part 2: Colorimetry and Turbidimetry; Chloride].
Sulfate [Part 2: Colorimetry and Turbidimetry; Sulfate; Procedure for Sulfate, Method 2]. Use 1.5 mL of hot dilute hydrochloric acid (1:1). Do two evaporations. Allow 30 min for turbidity to form.
Calcium, Iron, Lead, Nickel, Potassium, and Sodium (By flame AAS, [Part 2: Trace and Ultratrace Elemental Analysis; Atomic Absorption Spectroscopy; Analysis; Procedure for Flame AAS]).
© 2017 American Chemical Society
B
DOI:10.1021/acsreagents.4105 ACS Reagent Chemicals, Part 4
ACS Reagent Chemicals
Monograph
pubs.acs.org/doi/book/10.1021/acsreagents
For the Determination of Calcium, Iron, Lead, Nickel, Potassium, and Sodium
S a m p l e S t o c k S o l u t i o n . Dissolve 25.0 g of sample in 50 mL of water and 10 mL of nitric acid. Transfer to a 100 mL volumetric flask, and dilute to the mark with water (1 mL = 0.25 g).
For the Determination of Calcium, Iron, Lead, Nickel, Potassium, and Sodium
Element
Wavelength (nm)
Sample Wt (g)
Standard Added (mg)
Flame Type*
Background Correction
Ca
422.7
2.0
0.05; 0.10
N/A
No
Fe
248.3
2.0
0.10; 0.20
A/A
Yes
Pb
217.0
5.0
0.05; 0.10
A/A
Yes
Ni
232.0
2.0
0.10; 0.20
A/A
Yes
K
766.5
0.20
0.01; 0.02
A/A
No
Na
589.0
0.20
0.01; 0.02
A/A
No
*A/A is air/acetylene; N/A is nitrous oxide/acetylene.
© 2017 American Chemical Society
C
DOI:10.1021/acsreagents.4105 ACS Reagent Chemicals, Part 4
