Sodium hexanitrocobaltate (III)

Structural formula
General
Surname	Sodium hexanitrocobaltate (III)
other names	Cobalt sodium nitrite Sodium cobalt (III) nitrite
Molecular formula	CoN 6 Na 3 O 12
Brief description	yellow-brown powder with a faint odor of nitric acid
External identifiers / databases
EC number	237-077-7
ECHA InfoCard	100,033,692
PubChem	16211641
ChemSpider	13198283
Wikidata	Q2627834
properties
Molar mass	403.93 g mol −1
Physical state	firmly
density	2.56 g cm −3 (20 ° C)
Melting point	220 ° C (decomposition)
solubility	good in water (720 g l −1 at 20 ° C)
safety instructions
H and P phrases	H: 272-317-351
	P: 280-308 + 313-302 + 352
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Sodium hexanitrocobaltate (III) is an inorganic cobalt compound which can be used in concentrated aqueous solutions for the qualitative test for potassium and ammonium ions.

Representation and synthesis

Sodium hexanitrocobaltate (III) is produced by the oxidation of cobalt (II) salts in the presence of sodium nitrite .

For example, 4 parts of cobalt (II) nitrate hexahydrate can react with oxygen and 24 parts of sodium nitrite to form sodium hexanitrocobaltate (III), sodium nitrate , sodium hydroxide and water .

{\ displaystyle {\ ce {4 [Co (H2O) 6] (NO3) 2 + O2 + 24 NaNO2 -> 4 Na3 [Co (NO2) 6] + 8 NaNO3 + 4 NaOH + 22 H2O}}}

properties

Sodium hexanitrocobaltate (III) residue in a glass bottle

Sodium hexanitrocobaltate (III) is a yellow-brown solid that has a slight smell of nitric acid and is easily soluble in water . It decomposes when heated above 220 ° C.

Sodium hexanitrocobaltate (III) has a pH value of 5 (100 g / l water , 20 ° C) and is therefore slightly acidic in solution.

use

In geochemical analysis, sodium hexanitrocobaltate (III) is used to differentiate alkali feldspars from plagioclase feldspars in thin sections.

Sodium hexanitrocobaltate (III) is also a basic component of the quantitative analysis for ammonium , potassium or thallium ions .

safety instructions

Sodium hexanitrocobaltate (III) is suspected of being carcinogenic . It is also oxidizing.

Wear protective gloves, protective clothing, eye protection, face protection and respiratory protection when handling this material.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry for CAS no. 13600-98-1 in the GESTIS substance database of the IFA , accessed on January 22, 2020 (JavaScript required)
↑ SpringerMaterials: Na3 (Co (NO2) 6) (III) (Na3Co [NO2 6) Crystal Structure - SpringerMaterials], accessed on January 22, 2020
↑ Glemser, O. (1963). "Sodium Hexanitritocobaltate (III)". In Brauer, G. (ed.). Handbook of Preparative Inorganic Chemistry. 1 (2nd ed.). New York, NY: Academic Press. p. 1541.
↑ Bailey, EH; Stevens, RE (1960). "Selective staining of K-feldspar and plagioclase on rock slabs and thin sections". American mineralogist. 45: 1020-1025.
^ Vogel, AI (1951). Quantitative Inorganic Analysis (2nd ed.). Longmans Green and Co.

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ Entry for CAS no. 13600-98-1 in the GESTIS substance database of the IFA , accessed on January 22, 2020 (JavaScript required)

[springer.com-2] SpringerMaterials: Na3 (Co (NO2) 6) (III) (Na3Co [NO2 6) Crystal Structure - SpringerMaterials], accessed on January 22, 2020

[3] Glemser, O. (1963). "Sodium Hexanitritocobaltate (III)". In Brauer, G. (ed.). Handbook of Preparative Inorganic Chemistry. 1 (2nd ed.). New York, NY: Academic Press. p. 1541.

[4] Bailey, EH; Stevens, RE (1960). "Selective staining of K-feldspar and plagioclase on rock slabs and thin sections". American mineralogist. 45: 1020-1025.

[5] Vogel, AI (1951). Quantitative Inorganic Analysis (2nd ed.). Longmans Green and Co.