Zinc sulfide

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Zinc sulfide
Zinc sulfide sample by Zyklon-A.jpg
ZnS sample.
Names
IUPAC name
Zinc sulfide
Other names
Albalith
Sachtolith
Sphalerite
Wurtzite
Zinc monosulfide
Zincblende
Properties
ZnS
Molar mass 97.474 g/mol
Appearance White to yellowish solid
Density 4.090 g/cm3
Melting point 1,850 °C (3,360 °F; 2,120 K) (sublimes)
Boiling point Sublimes
alpha
0.00069 g/100 ml (18 °C)
beta
0.00065 g/100 ml (18 °C)
Solubility Reacts with strong acids
Thermochemistry
−204.6 kJ/mol
Hazards
Safety data sheet Sigma-Aldrich
Lethal dose or concentration (LD, LC):
2,000 mg/kg (rat, oral)
Related compounds
Related compounds
Zinc sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Zinc sulfide (or zinc sulphide) is a chemical with the chemical formula ZnS. Zinc sulfide fluoresces green, and is employed most often for its phosphorescent properties.

Properties

Chemical

Zinc sulfide can be roasted to release sulfur dioxide, leaving zinc oxide behind.

2 ZnS + 3 O2 → 2 ZnO + 2 SO2

Physical

Zinc sulfide is a white-yellowish solid, and it is widely used as a pigment. In its dense synthetic form, zinc sulfide can be transparent, and it is used as a window for visible optics and infrared optics. ZnS has a density of 4.090 g/cm3. It is poorly soluble in water but more soluble in acids. ZnS boils at 1,185 °C.

Availability

Zinc sulfide can be purchased from various science shops, as glowing powder.

Higher purity ZnS can be purchased from various chemical suppliers.

Preparation

Zinc sulfide is often produced by reacting zinc oxide with hydrogen sulfide, which produces zinc sulfide and water. Another method for producing the chemical is by heating a solution of zinc sulfate with sodium thiosulfate. A third way is to make a equimolar mix of zinc and sulfur powders and ignite the mix. This produces a bright green flame and impure ZnS. The impure ZnS can be purified through decantation.

Uses

Zinc sulfide can be used to produce hydrogen sulfide in a lab by the reaction with hydrochloric acid. The reaction proceeds as such:

ZnS + 2HCl → ZnCl2 + H2S

Projects

  • Make glowing powder
  • Hydrogen sulfide production
  • Sulfur dioxide generation

Handling

Safety

Zinc sulfide dust is irritant to the eyes, skin, if inhaled or ingested. In case of ingestion, it will release toxic hydrogen sulfide.

Storage

Zinc sulfide does not require special storage, although it should be kept away from any strong acid vapors, as it will release hydrogen sulfide gas on contact.

Disposal

Zinc sulfide doesn't require special disposal, though it can be neutralized with hydrogen peroxide. Avoid dumping it with acids though.

References

Relevant Sciencemadness threads