Hydrogen telluride is the inorganic compound

Inorganic compound

Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...

 with the formula H

Hydrogen

Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

₂Te

Telluride

Telluride may refer to:*Telluride, Colorado*Telluride , an ion of tellurium, and derivative compounds* A song by Tim McGraw on Set This Circus Down** A cover of the song by Josh Gracin on We Weren't Crazy...

. The simplest hydride of tellurium, it is rarely encountered because of it decomposes rapidly to the constituent elements. Most compounds with Te-H bonds (tellurol

Tellurol

Tellurols are analogues of alcohols and phenols where tellurium replaces oxygen. Tellurols, selenol, and thiols have similar properties, but tellurols are the least stable. Although they are fundamental representatives of organotellurium compounds, tellurols are lightly studied because of their...

s) are unstable with respect to loss of H₂. H₂Te is chemically and structurally similar to hydrogen selenide

Hydrogen selenide

Hydrogen selenide is the inorganic compound with the formula H2Se. It is the simplest and virtually the only hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compound with an exposure limit: 0.05 ppm over an 8 hour period...

, both are acidic. The H-Te-H angle is about 90°. Volatile tellurium compounds often have unpleasant odours, reminiscent of decayed leeks or garlic.

Synthesis

H₂Te is prepared by the acidification of salts of Te²⁻, such as Al₂Te₃ and Na₂Te. Na₂Te can be generated by the reaction of Na and Te in anhydrous ammonia

Ammonia

Ammonia is a compound of nitrogen and hydrogen with the formula . It is a colourless gas with a characteristic pungent odour. Ammonia contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or...

. The intermediate in the acidification, is a stable anion. Sodium hydrogen telluride, NaHTe, can be made by reducing tellurium with

Sodium borohydride

Sodium borohydride, also known as sodium tetrahydridoborate, is an inorganic compound with the formula NaBH4. This white solid, usually encountered as a powder, is a versatile reducing agent that finds wide application in chemistry, both in the laboratory and on a technical scale. Large amounts are...

.

Properties

is an endothermic

Endothermic

In thermodynamics, the word endothermic describes a process or reaction in which the system absorbs energy from the surroundings in the form of heat. Its etymology stems from the prefix endo- and the Greek word thermasi,...

 compound, unstable in air and easily oxidised to water and elemental tellurium:

2 + → 2 + 2 Te

It is almost as acidic as phosphoric acid

Phosphoric acid

Phosphoric acid, also known as orthophosphoric acid or phosphoric acid, is a mineral acid having the chemical formula H3PO4. Orthophosphoric acid molecules can combine with themselves to form a variety of compounds which are also referred to as phosphoric acids, but in a more general way...

(K_a = 8.1×10⁻³), having a K_a value of about 2.3×10⁻³. It reacts with many metals to form tellurides.