Full Answer
How is hydrogen selenide obtained from elements?
Hydrogen selenide can be obtained either directly from the elements at ca. 400 °C or by decomposition of the selenides of iron, magnesium, or aluminum with hydrochloric acid. Langner BE; Ullmann's Encyclopedia of Industrial Chemistry 7th ed. (1999-2011). New York, NY: John Wiley & Sons; Selenium and Selenium Compounds.
What is the ionization energy of hydrogen selenide?
DHHS (NIOSH) Publication No. 2005-151 (2005) Ionization energy: 9.892 eV Lide, D.R. CRC Handbook of Chemistry and Physics 88TH Edition 2007-2008. CRC Press, Taylor & Francis, Boca Raton, FL 2007, p. 10-209 For more Other Experimental Properties (Complete) data for HYDROGEN SELENIDE (7 total), please visit the HSDB record page.
What is the standard state of hydrogen selenide at different temperatures?
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). ?) Hydrogen selenide is an inorganic compound with the formula H 2 Se.
Is hydrogen selenide flammable?
This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. Furthermore, is hydrogen selenide polar or nonpolar?
Is Hydrogen Selenide ionic?
Its chemical formula is H2Se. It is an acid. It contains hydrogen and selenide ions.
What type of compound is Hydrogen Selenide?
Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compound with an exposure limit of 0.05 ppm over an 8-hour period.
What is selenide ion?
Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic.
Is Hydrogen Selenide a polar molecule?
Is H2Se polar or non-polar? H2Se is very slightly polar because of its bent geometrical shape and very small difference between the electronegativity of hydrogen and selenium, although, the polarity is so low between the atoms that H2Se is also considered as nonpolar in nature.
What is dihydrogen selenide?
Hydrogen diselenide is an inorganic selenium compound with a chemical formula H2Se2 or (SeH)2. At room temperature, hydrogen diselenide dissociates easily to hydrogen selenide (H2Se) and elemental selenium, and is therefore not stable.
What is hydrogen selenide used for?
Hydrogen Selenide is a colorless gas with an odor like decayed horseradish. It is used in the manufacture of organoselenium compounds and in semiconductors.
What is selenide charge?
A selenide is a chemical compound containing a selenium anion with oxidation number of −2 (Se2−), much as sulfur does in a sulfide.
What is the formula for selenide?
Selenide | Se-2 - PubChem.
Where is selenide on the periodic table?
oxygen groupselenium (Se), a chemical element in the oxygen group (Group 16 [VIa] of the periodic table), closely allied in chemical and physical properties with the elements sulfur and tellurium.
Is BeI2 polar or nonpolar?
BeI2 is a nonpolar molecule due to its linear geometry. Symmetrical or unsymmetrical distribution of charges or separation of charges determines the polarity of the molecule.
Is SeH2 polar covalent?
Decision: The molecular geometry of SeH2 is bent with asymmetric charge distribution on the central atom. Therefore this molecule is polar.
Is AsH3 polar covalent?
It's the AsH3 molecule's asymmetrical geometry. As a result, the AsH3 molecule is polar.
How is hydrogen selenide prepared?
Hydrogen selenide may be prepared by the action of acids or water on some metal selenides, usually aluminum selenide or iron selenide, or by passing hydrogen and selenium vapor over pumice at 177 °C resulting in a ca 58% yield.
What is the EPA hazardous waste number?
Generators of waste (equal to or greater than 100 kg/mo) containing this contaminant, EPA hazardous waste number D010 , must conform with USEPA regulations in storage, transportation, treatment and disposal of waste.
How long does it take for a guinea pig to die from selenide?
/LABORATORY ANIMALS: Acute Exposure/ The acute toxic effects of hydrogen selenide were investigated in guinea-pigs exposed for 10, 30, or 60 min to concentrations ranging from 0.002 to 0.57 mg/L. All animals exposed to 0.02 mg/L, for 60 min, died within 25 days; 93% of those exposed to 0.043 mg/L, for 30 min, died within 30 days, and all exposed to 0.57 mg/L, for 10 min, died within 5 days. Decreasing the concentrations of hydrogen selenide, and increasing the time of exposure to 2, 4, or 8 hr produced death in 50% of the guinea-pigs, within 8 hr.
What is the release requirement for CERCLA?
Releases of CERCLA hazardous substances are subject to the release reporting requirement of CERCLA section 103, codified at 40 CFR part 302, in addition to the requirements of 40 CFR part 355. Hydrogen selenide is an extremely hazardous substance (EHS) subject to reporting requirements when stored in amounts in excess of its threshold planning quantity (TPQ) of 10 lbs.
How to treat a contaminated eye?
If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. / Selenium and Related Compounds/
How to keep a fire cylinder cool?
In other cases extinguish with powder, carbon dioxide. In case of fire: keep cylinder cool by spraying with water. Combat fire from a sheltered position.
Why do compressed gases cause frostbite?
Compressed gases may create low temperatures when they expand rapidly. Leaks and uses that allow rapid expansion may cause a frostbite hazard. Wear appropriate personal protective clothing to prevent the skin from becoming frozen.
What does selenium smell like?
Even at extremely low concentrations, this compound has a very irritating smell resembling that of decayed horseradish or 'leaking gas', but smells of rotten eggs at higher concentrations.
Is selenium a hazardous substance?
Hydrogen selenide is hazardous, being the most toxic selenium compound and far more toxic than its congener hydrogen sulfide. The threshold limit value is 0.05 ppm. The gas acts as an irritant at concentrations higher than 0.3 ppm, which is the main warning sign of exposure; below 1 ppm, this is "insufficient to prevent exposure", while at 1.5 ppm the irritation is "intolerable". Exposure at high concentrations, even for less than a minute, causes the gas to attack the eyes and mucous membranes; this causes cold-like symptoms for at least a few days afterwards. In Germany, the limit in drinking water is 0.008 mg/L, and the US EPA recommends a maximum contamination of 0.01 mg/L.
What is the ionic element of lithium?
Ionic. The element of selenium and the element of lithium form a compound called lithium selenide. Note that the electronegativity of selenium is 2.4, and the electronegativity of lithium is 1.0.
What is the ionic bond of nitrogen?
Covalent. Ionic. Nitrogen, an element with an electronegativity of 3.0, and chlorine, an element with an electronegativity of 3.0, bond and form a compound called nitrogen trichloride.
Is barium fluoride covalent or ionic?
The electronegativity of barium is 0.9, and the electronegativity of fluorine is 4.0. Using the difference in electronegativity, predict whether this compound is ionic or covalent: Ionic .
Is rubidium oxide ionic or covalent?
Rubidium oxide consists of the rubidium, its electronegativity is 0.8, and oxygen, its electronegativity is 3.5. Will rubidium oxide be ionic or covalent? Covalent. Ionic. Lithium chloride, a compound composed of lithium and chlorine, which have an electronegativity of 1.0 and 3.0, respectively.
Is carbon ionic or covalent?
Carbon is moderately electronegative, with an electronegativity value of 2.5, and chlorine is highly electronegative, with an electronegativity value of 3.0. Is the compound carbon tetrachloride ionic or covalent?
Why H2S is an covalent compound?
A covalent bond is formed when sharing of electrons is done between the atoms to achieve the noble gas configuration and attains stability.
How covalent bond is formed in H2S?
The covalent bond is formed in H 2 S because of sharing of electrons occurs between hydrogen and a sulfur atom.
Why is H2S not a ionic compound?
H 2 S is not an ionic compound because the bond formed between hydrogen and sulfur is due to sharing of electrons. In ionic compounds, the bond is formed between two atoms by the exchange of electrons from one atom to another.
Is H2S pure covalent compound?
So, Is H2S a pure covalent bond? No, it is not. First of all, understand the actual means of a pure covalent bond.
Is H2S polar covalent or nonpolar covalent compound?
A polar covalent bond is formed when the difference between the electronegativity of atoms, resulting in between 0.4 to 1.7. Also, in a polar covalent bond, there is unequal sharing of electrons occurs due to the difference of electronegativity value of atoms.
Summary
That’s all, we have done almost all concepts and possible explanations about Is water (H 2 S) ionic or covalent? Bond types in H 2 S, why H 2 S is covalent and not an ionic compound? How covalent bond is formed in water (H 2 S)? Is covalent bond forms in H 2 S molecule is polar or nonpolar in nature?
How do covalent bonds form?
Covalent bonds form when two atoms share electrons. The covalent bonds are intramolecular bonds because they hold the atoms together in a single molecule. Covalent bond strengths range from 100 kJ/mol to 1100 kJ/mol.
What happens when an atom loses an electron?
The atom that loses an electron becomes a positive ion. The atom that gains an electron becomes a negative ion. The electrostatic attraction between these ions is an ionic bond. The ions in ionic solids are close to each other, so ionic attractions are strong.
Which compound has the strongest intermolecular force?
Hydrogen Bonds. Hydrogen bonds are especially strong intermolecular forces. They exist when you have a negative O, N, or F atom in one molecule and a positive H atom attached to an O, N, or F atom in another molecule. Water is the best-known compound that has hydrogen bonds.
Which is stronger, covalent or hydrogen?
The other three depend on the atoms in the bond, however, covalent are generally the strongest as they are the only physical bond. Hydro gen are the weakest as they aren’t bonds, they’re attractions between a permanent dipole on a hydrogen atom bonded to a highly electronegative atom and another highly electronegative atom.
Which is the weakest bond?
4 Answers. Hydrogen are the weakest as they aren’t bonds, they’re attractions between a permanent dipole on a hydrogen atom bonded to a highly electronegative atom and another highly electronegative atom. This makes them easiest to overcome as it isn’t a physical bond, just electrostatic. Hydrogen bonds differ to the other two greatly as they are ...
Is hydrogen a metallic bond?
When it comes to metallic bonds we do compare them in different metals. Hydrogen bond can be intramolecular or intermolecular. Generally they are weaker than intramolecular bonds. Actually ionic, covalent and metallic i.e the intramolecular bonds as we call them are all considered to be strong .
Is it wrong to assume that one is stronger than the other?
It is wrong to assume that one is stronger than the other . Usually what we do is to compare the bond in an ion ic compound with another ionic or the covalent bond in a substance with another covalent bond in another substance but not ionic bond in compound with a covalent bond in another substance.
Is hydrogen a physical bond?
This makes them easiest to overcome as it isn’t a physical bond, just electrostatic. Hydrogen bonds differ to the other two greatly as they are intermolecular, not between lone atoms, this also means they only occur in molecules (covalent species) - NO other type of bonding.
Overview
Hydrogen selenide is an inorganic compound with the formula H2Se. This hydrogen chalcogenide is the simplest and most commonly encountered hydride of selenium. H2Se is a colorless, flammable gas under standard conditions. It is the most toxic selenium compound with an exposure limit of 0.05 ppm over an 8-hour period. Even at extremely low concentrations, this compound has a very irritating smell resembling that of decayed horseradish or 'leaking gas', but smells of rotten eggs at higher concentrations.
Structure and properties
H2Se adopts a bent structure with a H−Se−H bond angle of 91° . Consistent with this structure, three IR-active vibrational bands are observed: 2358, 2345, and 1034 cm .
The properties of H2S and H2Se are similar, although the selenide is more acidic with pKa = 3.89, and the second pKa = 11, or 15.05 ± 0.02 at 25 °C.
Preparation
Industrially, it is produced by treating elemental selenium at T > 300 °C with hydrogen gas. A number of routes to H2Se have been reported, which are suitable for both large and small scale preparations. In the laboratory, H2Se is usually prepared by the action of water on Al2Se3, concomitant with formation of hydrated alumina. A related reaction involves the acid hydrolysis of FeSe.
Al2Se3 + 6 H2O ⇌ 2 Al(OH)3 + 3 H2Se
Reactions
Elemental selenium can be recovered from H2Se through a reaction with aqueous sulfur dioxide (SO2).
2 H2Se + SO2 ⇌ 2 H2O + 2 Se + S
Its decomposition is used to prepare the highly pure element.
Applications
H2Se is commonly used in the synthesis of Se-containing compounds. It adds across alkenes. Illustrative is the synthesis of selenoureas from cyanamides.
H2Se gas is used to dope semiconductors with selenium.
Safety
Hydrogen selenide is hazardous, being the most toxic selenium compound and far more toxic than its congener hydrogen sulfide. The threshold limit value is 0.05 ppm. The gas acts as an irritant at concentrations higher than 0.3 ppm, which is the main warning sign of exposure; below 1 ppm, this is "insufficient to prevent exposure", while at 1.5 ppm the irritation is "intolerable". Exposure at high concentrations, even for less than a minute, causes the gas to attack the eyes and mucous membranes; this causes cold-like symptoms for at least a few days afterwar…
See also
• Hydrogen diselenide
External links
• WebElements page on compound's properties
• CDC - NIOSH Pocket Guide to Chemical Hazards