Cesium Polysulfides

Cesium Polysulfides
Cesium Polysulfides
Are common
Systematic ; name	Cesium polysulfide
Traditional names	Cesium sulphide
Chem. formula	Cs 2 S n

Cesium polysulfides are binary chemical compounds of cesium and sulfur with the formula Cs ₂ S _n (where n = 2 ÷ 6 ), the molecules of which, like other polysulfides , contain dimeric / polymer chains of sulfur atoms —S _(n) -. Under normal conditions, yellow-brown crystals.

Getting

By fusing cesium sulfide with sulfur , a mixture of polysulfides is obtained:

{\mathsf {Cs_{2}S+{\mathit {n}}S\ {\xrightarrow {\tau ^{o}C}}\ Cs_{2}S_{{\mathit {n}}+1}}}

{\ displaystyle {\ mathsf {Cs_ {2} S + {\ mathit {n}} S \ {\ xrightarrow {\ tau ^ {o} C}} \ Cs_ {2} S _ {{\ mathit {n}} + 1 }}}}

the result can be controlled by the amount of sulfur and the reaction temperature. Also, this reaction can be carried out in an alkalized boiling aqueous solution.

Physical Properties

Cesium polysulfides are yellow-brown solids. Melts are dark brown mobile fluids. They dissolve well in water, the solutions are dark yellow in color.

Properties of some cesium polysulfides
Polysulfide	Molar mass	Density	Temperature melting point (° C)	Appearance	Crystal hydrate
Cs ₂ s ₂	329.94		460	Dark red	Cs ₂ S ₂ H ₂ O
Cs ₂ s ₃	362.01		217	Orange
Cs ₂ s ₄	394.06			yellow
Cs ₂ s ₅	426.14	2,806	210		Cs ₂ S ₅ H ₂ O
Cs ₂ S ₆	458.21	3,076	185	red brown

Chemical Properties

With strong heating, decompose with the release of sulfur:

{\mathsf {Cs_{2}S_{\mathit {n}}\ {\xrightarrow {>600^{o}C}}\ Cs_{2}S+({{\mathit {n}}-1})S}}

{\ displaystyle {\ mathsf {Cs_ {2} S _ {\ mathit {n}} \ {\ xrightarrow {> 600 ^ {o} C}} \ Cs_ {2} S + ({{\ \ mathit {n}} - 1 }) S}}}

Aqueous solutions have an alkaline reaction due to anion hydrolysis :

{\mathsf {S_{\mathit {n}}^{2-}+H_{2}O\ \rightleftarrows \ HS_{\mathit {n}}^{-}+OH^{-}}}

{\ displaystyle {\ mathsf {S _ {\ mathit {n}} ^ {2 -} + H_ {2} O \ \ rightleftarrows \ HS _ {\ mathit {n}} ^ {-} + OH ^ {-}}} }

At room temperature they decompose with dilute acids, releasing sulfur:

{\mathsf {Cs_{2}S_{\mathit {n}}+2\ HCl\ {\xrightarrow {20^{o}C}}\ 2\ CsCl+H_{2}S\uparrow +({{\mathit {n}}-1})S\downarrow }}

{\ displaystyle {\ mathsf {Cs_ {2} S _ {\ mathit {n}} + 2 \ HCl \ {\ xrightarrow {20 ^ {o} C}} \ 2 \ CsCl + H_ {2} S \ uparrow + ( {{\ mathit {n}} - 1}) S \ downarrow}}}

At low temperature and concentrated acid, polysulfanes can be obtained:

{\mathsf {Cs_{2}S_{\mathit {n}}+2\ HCl\ {\xrightarrow {-15^{o}C}}\ 2\ CsCl+H_{2}S_{\mathit {n}}}}

{\ displaystyle {\ mathsf {Cs_ {2} S _ {\ mathit {n}} + 2 \ HCl \ {\ xrightarrow {-15 ^ {o} C}} \ 2 \ CsCl + H_ {2} S _ {\ mathit {n}}}}}

In a humid environment and in the light, cesium polysulfides are oxidized by atmospheric oxygen:

{\mathsf {2\ Cs_{2}S_{\mathit {n}}+2\ H_{2}O+O_{2}\ {\xrightarrow {\ }}\ 4\ CsOH+2{\mathit {n}}S}}

{\ displaystyle {\ mathsf {2 \ Cs_ {2} S _ {\ mathit {n}} + 2 \ H_ {2} O + O_ {2} \ {\ xrightarrow {\}} \ 4 \ CsOH + 2 {\ mathit {n}} S}}}

Literature

Chemical Encyclopedia / Editorial: Zefirov N.S. et al. - M .: Big Russian Encyclopedia, 1998. - V. 5. - 783 p. - ISBN 5-85270-310-9 .
Lidin R.A. and other Chemical properties of inorganic substances: Textbook. manual for universities. - 3rd ed., Rev. - M .: Chemistry, 2000 .-- 480 p. - ISBN 5-7245-1163-0 .
Chemistry Handbook / Editorial: Nikolsky B.P. et al. - 3rd ed., rev. - L .: Chemistry, 1971. - T. 2. - 1168 p.
Ripan R., Chetyanu I. Inorganic chemistry. Chemistry of metals. - M .: Mir, 1971. - T. 1. - 561 p.
Plyushchev V.E., Stepin B.D. Chemistry and technology of compounds of lithium, rubidium and cesium. - M .: "Chemistry", 1970. - 408 p.

Cesium Polysulfides

Getting

Physical Properties

Chemical Properties

See also

Literature

More articles:

Cesium Polysulfides
Are common
Systematic name	Cesium polysulfide
Traditional names	Cesium sulphide
Chem. formula	Cs ₂ S _n