Chemistry:Sodium hydrosulfide

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Sodium hydrosulfide
Sodium-hydrosulfide-LT-xtal-1991-CM-3D-balls.png
Names
IUPAC name
Sodium hydrosulfide
Other names
Sodium bisulfide
Sodium sulfhydrate
Sodium hydrogen sulfide
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
EC Number
  • 240-778-0
RTECS number
  • WE1900000
UNII
UN number 2922 2318
Properties
NaSH
Molar mass 56.063 g/mol
Appearance off-white solid, deliquescent
Density 1.79 g/cm3
Melting point 350.1 °C (662.2 °F; 623.2 K) (anhydrous)
55 °C (dihydrate)
22 °C (trihydrate)
50 g/100 mL (22 °C)
Solubility soluble in alcohol, ether
Structure
rhombohedral
Hazards
Main hazards Flammable solid, stench, releases hydrogen sulfide
Safety data sheet TDC MSDS
GHS pictograms GHS02: FlammableGHS05: CorrosiveGHS06: ToxicGHS09: Environmental hazard
GHS Signal word Danger
H226, H251, H290, H301, H314, H318, H400
P210, P233, P234, P235+410, P240, P241, P242, P243, P260, P264, P270, P273, P280, P301+310, P301+330+331, P303+361+353, P304+340, P305+351+338, P310, P321, P330, P363, P370+378, P390, P391
NFPA 704 (fire diamond)
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g. diesel fuelHealth code 3: Short exposure could cause serious temporary or residual injury. E.g. chlorine gasReactivity (yellow): no hazard codeSpecial hazards (white): no codeNFPA 704 four-colored diamond
2
3
Flash point 90 °C (194 °F; 363 K)
Related compounds
Other anions
Sodium hydroxide
Sodium amide
Other cations
Ammonium hydrosulfide
Related compounds
Sodium sulfide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references
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Sodium hydrosulfide is the chemical compound with the formula NaSH. This compound is the product of the half-neutralization of hydrogen sulfide (H
2
S
) with sodium hydroxide (NaOH). NaSH and sodium sulfide are used industrially, often for similar purposes. Solid NaSH is colorless. The solid has an odor of H
2
S
owing to hydrolysis by atmospheric moisture. In contrast with sodium sulfide (Na
2
S
), which is insoluble in organic solvents, NaSH, being a 1:1 electrolyte, is more soluble.

Structure and properties

Crystalline NaHS undergoes two phase transitions. At temperatures above 360 K, NaSH adopts the NaCl structure, which implies that the HS
behaves as a spherical anion owing to its rapid rotation, leading to equal occupancy of eight equivalent positions. Below 360 K, a rhombohedral structure forms, and the HS
sweeps out a discoidal shape. Below 114 K, the structure becomes monoclinic. The analogous rubidium and potassium compounds behave similarly.[1]

NaSH has a relatively low melting point of 350 °C. In addition to the aforementioned anhydrous forms, it can be obtained as two different hydrates, NaSH · 2H2O and NaSH · 3H2O. These three species are all colorless and behave similarly, but not identically. It can be used to precipitate other metal hydrosulfides, by treatment of aqueous solutions of their salts with sodium hydrosulfide. It is analogous to sodium hydroxide, and is a strong base.

Preparation

One laboratory synthesis entails treatment of sodium ethoxide (NaOEt) with hydrogen sulfide:[2]

NaOCH
2
CH
3
+ H
2
S → NaSH + CH
3
CH
2
OH

An alternative method involves reaction of sodium with hydrogen sulfide.[3]

Applications

Thousands of tons of NaSH are produced annually. Its main uses are in cloth and paper manufacture as a makeup chemical for sulfur used in the kraft process, as a flotation agent in copper mining where it is used to activate oxide mineral species, and in the leather industry for the removal of hair from hides.[4]

References

  1. Haarmann, F.; Jacobs, H.; Roessler, E.; Senker, J. (2002). "Dynamics of anions and cations in hydrogensulfides of alkali metals (NaHS, KHS, RbHS): A proton nuclear magnetic resonance study". J. Chem. Phys. 117 (3): 1269–1276. doi:10.1063/1.1483860. Bibcode2002JChPh.117.1269H. 
  2. Eibeck, R. I. (1963). "Sodium Hydrogen Sulfide". Inorganic Syntheses 7: 128–31. doi:10.1002/9780470132388.ch35. ISBN 9780470132388. 
  3. Pavlik, Jeffrey W.; Noll, Bruce C.; Oliver, Allen G.; Schulz, Charles E.; Scheidt, W. Robert (2010). "Hydrosulfide (HS) Coordination in Iron Porphyrinates". Inorganic Chemistry 49 (3): 1017–1026. doi:10.1021/ic901853p. PMID 20038134. 
  4. Butts, David; Bush, David R.; Updated By Staff (2013). "Sodium Sulfates and Sulfides". Kirk-Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.1915040902212020.a01.pub3. ISBN 978-0471238966.