Barium manganate

Crystal structure
Crystal system	tetragonal
Space group	I 4 1 / a (No. 88)
General
Surname	Barium manganate
other names	Barium manganate (VI)
Ratio formula	BaMnO 4
Brief description	dark gray powder
External identifiers / databases
CAS number 7787-35-1 EC number 232-109-6 ECHA InfoCard 100.029.190 PubChem 3084030 ChemSpider 2341155 Wikidata Q4280210
properties
Molar mass	256.26 g mol −1
Physical state	firmly
density	4.85 g cm −3 (25 ° C)
solubility	Insoluble in water
safety instructions
GHS labeling of hazardous substances danger H and P phrases H: 272-302 + 332 P: 220
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Barium manganate , BaMnO ₄ , is the barium salt from the group of manganates . In contrast to barium permanganate , the manganese in barium manganate has the oxidation state + VI.

Extraction and presentation

Barium manganate can be obtained by reacting the two salts potassium manganate and barium chloride .

${\displaystyle {\ce {K2MnO4 + BaCl2 -> BaMnO4 + 2 KCl}}}$

Heating manganese (IV) oxide with barium carbonate or barium nitrate also creates the salt.

properties

Physical Properties

Under normal conditions, the salt has a structure similar to scheelite . It crystallizes in a tetragonal crystal system with the space group I 4 ₁ / a (space group no. 88) . Analogous to barium tungstate, it transforms at a pressure of 5.8 GPa to a monoclinic fergusonite structure of space group I 2 / a (space group no. 15, position 3) .

Chemical properties

The production of permanganic acid is possible with barium manganate and sulfuric acid .

${\displaystyle {\ce {3 BaMnO4 + 3 H2SO4 -> 2 HMnO4 + 3 BaSO4 + MnO2 + 2 H2O}}}$

use

Barium manganate was used in organic chemistry for the oxidation of primary alcohols to aldehydes and carboxylic acids .

Individual evidence

1. ↑ ^{a b c d} data sheet barium manganate from Sigma-Aldrich , accessed on July 26, 2019 ( PDF ).
2. ↑ ^{a b c} Richard C. Ropp: Encyclopedia of the Alkaline Earth Compounds . Newnes, 2012, ISBN 0-444-59553-8 , pp. 895 .
3. ^ Nicholas Eastaugh, Valentine Walsh, Tracey Chaplin, Ruth Siddall: Pigment Compendium . Routledge, 2008, ISBN 1-136-37392-6 , pp. 43-44 .