Terbium sulfate

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Terbium sulfate
Terbium sulfate.jpg
Terbium sulfate fluorescing in a plastic bag
Names
IUPAC name
Terbium(III) sulfate
Other names
Diterbium trisulphate
Properties
Tb2(SO4)3
Molar mass 750.16
Appearance White crystalline solid
Odor Odorless
Melting point 360 °C (680 °F; 633 K) (decomposes)[1]
Boiling point Decomposes
Slightly soluble
Solubility Insoluble in hydrocarbons
Vapor pressure ~0 mmHg
Hazards
Safety data sheet Sigma-Aldrich
Flash point Non-flammable
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Terbium sulfate is an ionic compound with the formula Tb2(SO4)3. It is notable for being extremely fluorescent, emitting bright green light under shortwave ultraviolet light. It is relatively insoluble in water, especially when precipitated with potassium sulfate, forming a double sulfate with the formula KTb(SO4)2.

Properties

Chemical

Terbium sulfate is generally inert to reduction or oxidation. Heating to approximately 1500 degrees Celsius, however, produces terbium(III,IV) oxide. Its solubility in water decreases with heating, but it has a tendency to supersaturate, and a supersaturated solution of terbium sulfate may not crystallize for days.

Physical

Terbium sulfate appears to crystallize in the hexagonal crystal system. It is a white solid that can be quite powdery when crushed. As a powder, it passes very easily through filter paper.

Availability

Terbium sulfate is extremely difficult to find at a reasonable price, but the materials needed for preparation, terbium metal and sulfuric acid, can be found quite easily.

Preparation

Terbium sulfate can be made by adding terbium metal to sulfuric acid. Terbium sulfate, however, does not dissolve in water easily, so stirring the metal to remove the layers of terbium sulfate powder helps greatly.

Projects

  • Make fluorescent crystals

Handling

Safety

Terbium sulfate does not appear to be particularly toxic.

Storage

Terbium sulfate should be kept in closed plastic or glass bottles, away from moisture and acids.

Disposal

Due to the rarity of terbium, it's best to recycle it.

References

  1. David R. Lide (Hrsg.): CRC Handbook of Chemistry and Physics. 90. Auflage. (Internet-Version: 2010), CRC Press/Taylor and Francis, Boca Raton, FL, Properties of the Elements and Inorganic Compounds, S. 4-94
I vouch for pretty much everything. Brain&Force (talk) 04:03, August 19, 2014 (UTC)

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