Hydrogen telluride Chemical Properties

Melting point:

-49°

Boiling point:

bp -2°

Density 

dliq-12 2.68

solubility 

soluble in H2O, ethanol, alkaline solutions

form 

colorless gas

color 

colorless

Water Solubility 

soluble H2O, unstable solution; soluble alcohol and alkalies [HAW93]

CAS DataBase Reference

7783-09-7

Hydrogen telluride Usage And Synthesis

Description

Hydrogen telluride has the formula, H2Te. The simplest hydride of Te, it is rarely encountered because of its tendency to decompose to the constituent elements. Most compounds with Te–H bonds are unstable with respect to loss of H2. H2Te is chemically and structurally similar to H2S, and both are acidic species with H–X–H angles approaching 90°.The tellurides of the alkaline earth metals tend to immediately decompose on exposure to air, with liberation of tellurium. H2Te is prepared by the acidification of salts of Te^2-,such as Al2Te3 and Na2Te.
Na2Te can be generated by the reaction of Na and Te in anhydrous ammonia. The intermediate in the acidification, the HTe is a stable anion.
H2Te is an endothermic compound, and is unstable in air, rapidly decomposing into water and elemental tellurium:
2H2Te+ O2 → 2H2O+ 2Te
It is almost as acidic as phosphoric acid (pK_a=8.1×10^-3), having a pK_a value of about 2.3×10^-3. It reacts with many metals to form tellurides. However, many of these are unstable relative to their decomposition to the elements. Its CAS number is 7783-09-7 and its molecular weight is 129.6158 g/mol. It is a colorless gas and is toxic if breathed. Its density is 3.310 g/cm3 and its melting point is –49°C with a boiling point of –2.2°C. Its solubility in water is 0.701 g/100 ml of water at 20°C.

Chemical Properties

Colorless gas.Soluble in water but unstable; soluble in alcohol and alkalies.

Physical properties

Colorless gas; strong garlic-like odor; stable to light when dry but under-goes photochemical decompostion in the presence of moisture and dust; den-sity 5.68 g/L; liquefies to a colorless unstable liquid at -2°C, decomposed bylight; liquid density 2.57 g/mL at -20°C; solidifies at -49°C; soluble in water,alcohol and alkalies; pKa 2.6 (for first dissociation constant at 18°C) and 11.0(the dissociation constant at 25°C) for the second replaceable hydrogen.

Uses

It is synthesized by the action of acid on aluminum telluride. It has no industrial uses.

Preparation

Hydrogen telluride is prepared by the reaction of aluminum telluride,Al₂Te₃ with hydrochloric acid:
Al2Te₃ + 6HCl → 3H₂Te + 2AlCl₃
It also may be prepared by electrolysis of a 50% sulfuric acid solution using atellurium cathode.

Hazard

See hydrogen selenide.

Hydrogen telluride(7783-09-7)Related Product Information

• Selenium dioxide
• Iron Oxide Black
• TELLURIC ACID
• STRONTIUM TELLURIDE
• STRONTIUM TELLURITE
• STRONTIUM TELLURATE
• CALCIUM TELLURIDE, 99.99%
• Tellurous acid
• BARIUM TELLURIDE
• Beryllium tellurate
• MAGNESIUM TELLURIDE
• Magnesium Tellurate
• Beryllium Tellurite
• Telluric acid (H2teo4), barium salt (1:1)
• Magnesium Tellurite
• Radium Tellurite
• Barium Tellurite
• Tellurium