Sodium disulfide

Sodium disulfide
Sodium disulfide
General
Systematic ; name	Sodium disulfide
Traditional names	Sodium sulfide; disodium disulfane; (2-) sodium disulfide
Chem. formula	Na 2 S 2
Physical properties
condition	yellow crystals
Molar mass	110.11 g / mol
Thermal properties
T. melt.	445; 475; ≈490 ° C
Enthalpy of Education	-397 kJ / mol
Classification
Reg. CAS number	22868-13-9
PubChem
Reg. EINECS number	245-272-3
Smiles
Inchi
ChemSpider

Sodium disulfide is a binary inorganic compound of sodium and sulfur with the formula Na ₂ S ₂ , yellow crystals, it dissolves in water, forms crystalline hydrates .

Content

1 Receiving
2 Physical properties
3 Application
4 Literature

Getting

The reaction of solutions of sodium and sodium tetrasulfide :

{\mathsf {Na_{2}S_{4}+2Na\ {\xrightarrow {80^{o}C}}\ 2Na_{2}S_{2}\downarrow }}

{\ displaystyle {\ mathsf {Na_ {2} S_ {4} + 2Na \ {\ xrightarrow {80 ^ {o} C}} \ 2Na_ {2} S_ {2} \ downarrow}}}

Vacuum fusion of stoichiometric amounts of sodium sulfide and sulfur

{\mathsf {Na_{2}S+S\ {\xrightarrow {500^{o}C}}\ Na_{2}S_{2}}}

{\ displaystyle {\ mathsf {Na_ {2} S + S \ {\ xrightarrow {500 ^ {o} C}} \ Na_ {2} S_ {2}}}}

Obtaining from pure substances dissolved in liquid ammonia :

{\mathsf {2Na+2S\ {\xrightarrow {-33^{o}C}}\ Na_{2}S_{2}}}

{\ displaystyle {\ mathsf {2Na + 2S \ {\ xrightarrow {-33 ^ {o} C}} \ Na_ {2} S_ {2}}}}

Physical Properties

Sodium disulfide forms yellow crystals of several modifications:

α-Na ₂ S ₂ , hexagonal syngony , space group P 6 2m , cell parameters a = 0.7629 nm, c = 0.5394 nm;
β-Na ₂ S ₂ , hexagonal syngony , space group P 6 ₃ / mmc , cell parameters a = 0.4494 nm, c = 1.0228 nm.

It is soluble in water, slightly soluble in ethanol .

When heated, it darkens and at 400 ° C turns a light red-brown color. In the melt is a mobile dark brown liquid.

Forms a crystalline hydrate of the composition Na ₂ S ₂ • 5H ₂ O.

Application

See Sodium Polysulfides .

Literature

Chemical Encyclopedia / Editorial Board: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1992. - T. 3. - 639 p. - ISBN 5-82270-039-8 .
Chemistry Handbook / Editorial: Nikolsky B.P. et al. - 3rd ed., rev. - L .: Chemistry, 1971. - T. 2. - 1168 p.
Inorganic Synthesis Guide: 6 Vol. / Ed. Brower G. - M .: Mir, 1985 .-- T. 2 .-- 338 p.
State Diagrams of Double Metal Systems / Ed. N.P. Lyakisheva. - M .: Engineering, 2001. - T. 3 Book 1. - 972 p. - ISBN 5-217-02843-2 .
Chemical Encyclopedic Dictionary / Editorial: Knunyants I.L. et al. - M .: Soviet Encyclopedia, 1983. - 792 p.