Sodium metaborate

Structural formula
General
Surname	Sodium metaborate
other names	Sodium dioxoborate
Molecular formula	NaBO 2
Brief description	white odorless solid
External identifiers / databases
ECHA InfoCard	100.028.992
PubChem	145326
Wikidata	Q3333421
properties
Molar mass	65.80 g mol −1
Physical state	firmly
density	2.34
Melting point	965 ° C
boiling point	1474 ° C
solubility	soluble in water (480 g l −1 )
safety instructions
H and P phrases	H: 319-361
	P: 261-305 + 351 + 338
Toxicological data	2330 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Sodium metaborate is an inorganic chemical compound of sodium from the borate group .

Extraction and presentation

Sodium metaborate can be obtained by reacting sodium carbonate with boric acid .

{\ displaystyle \ mathrm {Na_ {2} CO_ {3} +2 \ H_ {3} BO_ {3} \ longrightarrow 2 \ NaBO_ {2} + CO_ {2} +3 \ H_ {2} O}}

Sodium metaborate can also be obtained by reacting sodium hydroxide with sodium tetraborate . The dihydrate is produced by heating a slurry of the tetrahydrate above 54 ° C. The tetrahydrate converts to the anhydrate at 120 ° C.

Sodium metaborate is also formed when water reacts with sodium perborate .

properties

Sodium metaborate is a white, odorless solid that is soluble in water. It has a trigonal crystal structure (a = 1192.5 pm, c = 643.9 pm) with the space group R 3 c (space group no. 167) . The dihydrate, which is stable at room temperature, has a triclinic crystal structure. Template: room group / 167

use

Sodium metaborate is used as an additive in photographic developers, electroplating baths and herbicides.

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Entry on sodium metaborate, anhydrous in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .
↑ ^a ^b ^c ^d Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 809.
^ ^A ^b Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 602 ( limited preview in Google Book search).
↑ Data sheet Sodium metaborate tetrahydrate, ≥99% from Sigma-Aldrich , accessed on February 15, 2014 ( PDF ).
^ Entry on sodium metaborate in the Hazardous Substances Data Bank , accessed February 15, 2014.
^ ^A ^b Mary Eagleson: Concise Encyclopedia Chemistry . Walter de Gruyter, 1994, ISBN 3-11-011451-8 , p. 999 ( limited preview in Google Book Search).
↑ Endodontology: textbook for study and work; with 46 tables . Deutscher Ärzteverlag, 2011, ISBN 3-7691-3421-4 , p. 457 ( limited preview in Google Book search).
↑ John Krc: Crystallographic Data. 44. Sodium Metaborate Dihydrate. In: Analytical Chemistry. 23, 1951, pp. 806-806, doi : 10.1021 / ac60053a043 .

[GESTIS-1] ↑ ^a ^b ^c ^d ^e ^f Entry on sodium metaborate, anhydrous in the GESTIS substance database of the IFA , accessed on February 1, 2016(JavaScript required) .

[brauer-2] Georg Brauer (Ed.), With the collaboration of Marianne Baudler a . a .: Handbook of Preparative Inorganic Chemistry. 3rd, revised edition. Volume I, Ferdinand Enke, Stuttgart 1975, ISBN 3-432-02328-6 , p. 809.

[Lax-3] A ^b Jean d'Ans, Ellen Lax, Roger Blachnik: Pocket book for chemists and physicists . Springer DE, 1998, ISBN 3-642-58842-5 , pp. 602 ( limited preview in Google Book search).

[Sigma-4] Data sheet Sodium metaborate tetrahydrate, ≥99% from Sigma-Aldrich , accessed on February 15, 2014 ( PDF ).

[HSDB-5] Entry on sodium metaborate in the Hazardous Substances Data Bank , accessed February 15, 2014.

[Mary_Eagleson-6] A ^b Mary Eagleson: Concise Encyclopedia Chemistry . Walter de Gruyter, 1994, ISBN 3-11-011451-8 , p. 999 ( limited preview in Google Book Search).

[7] Endodontology: textbook for study and work; with 46 tables . Deutscher Ärzteverlag, 2011, ISBN 3-7691-3421-4 , p. 457 ( limited preview in Google Book search).

[DOI10.1021/ac60053a043-8] John Krc: Crystallographic Data. 44. Sodium Metaborate Dihydrate. In: Analytical Chemistry. 23, 1951, pp. 806-806, doi : 10.1021 / ac60053a043 .