In the year 1777, a German and Swedish Pomeranian pharmaceutical chemist Carl Wilhelm Scheele discovered the chemical composition of hydrogen sulfide (H2S).
H2S chemical name is hydrogen sulfide. It is made of hydrogen and sulfur (H2 and S, respectively). The symbol of hydrogen sulfide is H2S.
H2S is a colourless chalcogen hydride gas with the prevalent foul smell of rotten eggs. It is a poisonous, corrosive, and flammable gas.
Every now and again, hydrogen sulfide is set up by the microbial breakdown of natural (organic) matter without oxygen gas, as in bogs and sewers. This interaction is usually called anaerobic absorption, which is performed by sulfate-reducing microorganisms.
On this page, we will understand more about hydrogen sulfide, its preparation, properties, and uses in detail.
Do You Know?
The British English spelling of the H2S compound name is hydrogen sulphide; however, this spelling is not accepted by the International Union of Pure and Applied Chemistry (in short, IUPAC) or the Royal Society of Chemistry.
Hydrogen Sulfide Properties
Hydrogen sulfide is an exceptionally harmful and combustible, dull gas with a trademark scent of spoiled eggs. It is utilized in the assembling of synthetic compounds, in metallurgy, and as an insightful reagent. It is heavier than air and will in general collect at the lower part of inadequately ventilated spaces. Albeit impactful from the start, it rapidly stifles the feeling of smell.
Hydrogen sulfide happens normally in rough oil, petroleum gas, volcanic gases, and underground aquifers. It can likewise result from the bacterial breakdown of natural matter. It is likewise created by human and creature squanders.
Hydrogen sulfide is utilized in the production of synthetic compounds, in metallurgy, and as an analytical reagent. A few properties of H2S compound name are as follows:
Properties of H2S Compound Name
|
Parameters |
Corresponding Value |
|
Chemical Formula of Hydrogen Sulfide |
H2S (hydrogen sulphur) |
|
Synonyms |
Dihydrogen monosulfide Sewer gas Dihydrogen sulfide Sour gas Sulfane Sulfur hydride |
|
Hydrogen sulfide chemical structure |
[Image] |
|
Appearance |
Colourless gas |
|
Smell |
Rotten eggs |
|
Boiling point |
-76°F -60°C -213 K |
|
Melting point |
-115.60°F -82°C -191 K |
|
Average molar mass |
34.08 g/mol |
|
Classification |
Sulfur – sulfur compounds |
|
Solubility in water |
4 g/dm3 at 20 °C |
|
Vapour pressure |
1740 kPa (at 21 °C) |
|
Acidity (pKa) |
7.0 |
|
Conjugate acid |
Sulfonium |
|
Conjugate base |
Bisulifide |
|
Refractive index (nD) |
1.000644 (0 °C) |
|
Magnetic susceptibility |
– 25.5·10−6 cm3/mol |
Hydrogen Sulfide Structure
|
Printing group |
C2v |
|
Molecular shape |
[Image] |
|
Dipole moment |
0.97 D |
Hydrogen Sulfide Thermochemistry
|
Thermal heat capacity |
1.003 J K−1 g−1 |
|
Standard molar entropy (So298 at 298 K |
206 J mol−1 K−1 |
|
Std enthalpy of formation (ΔfH⦵298) |
– 21 kJ mol−1 |
|
Critical temperature |
373.3 K 100.2 °C 212.3 °F |
|
Critical pressure |
8.97 MPa 8.97 bar 88.5 atm 1301 psi |
|
Critical volume |
98 cm3/mol 0.00288 m3/kg 1.48 ft3/slug 0.0461 ft3/lb |
|
Density |
44.16 mol/m3 1.505 kg/m3 0.00292 slug/ft3 61.95 lb/ft3 |
Hydrogen Sulfide Hazards
Hydrogen sulfide is somewhat denser than air; a combination of H2S and air can be explosive.
The explosive properties of Hydrogen Sulfur (or if we write the chemical formula of hydrogen sulphide, it is H2S) are as follows:
|
Main Dangers |
Flammable and Highly Toxic |
|
EU (European classification) |
[Image] |
|
R phases |
R12 R26 R50 |
|
S phases |
(S1/2) S9 S16 S36 S38 S45 S61 |
|
Flash point |
− 82.4 °C − 116.3 °F 190.8 K |
|
Explosive percentage |
4.3 – 4.6 % |
|
Autoignition temperature |
232 °C 450 °F 505 K |
|
Lethal Dose LD50 (median concentration) |
444 ppm (rat, 4 hr) 634 ppm (mouse, 1 hr) 673 ppm (mouse, 1 hr) 713 ppm (rat, 1 hr) |
|
Lethal concentration LC50 |
600 ppm (human, 30 min) 800 ppm (human, 5 min) |
Hydrogen Sulfide Properties
Hydrogen sulfide combines with oxygen and gives off a blue fire to frame sulfur dioxide (SO2) and water. As a rule, hydrogen sulfide goes about as a diminishing specialist, particularly within the sight of base, which structures SH−.
At high temperatures or within the sight of impetuses, sulfur dioxide reacts with hydrogen sulfide to frame natural sulfur and water. This response is misused in the Claus interaction, a significant mechanical strategy to discard hydrogen sulfide.
Hydrogen sulfide is marginally solvent in water and goes about as a frail corrosive (pKa = 6.9 in 0.01 = 0.1 mol/litre arrangements at 18 °C), giving the hydrosulfide particle HS−.
(likewise composed SH−).
Hydrogen sulfide and its solutions are colourless. When presented to air, it gradually oxidizes to frame natural sulfur, which isn’t dissolvable in water. The sulfide anion S2− isn’t found in an aqueous solution.
Hydrogen Sulfide Geometry
Hydrogen sulfide goes about as a reducing specialist. H2S Lewis structure is a combination of hydrogens and one sulfur atom. Sulfur is the focal particle and contains 2 solitary sets though both hydrogens are associated with the focal molecule with the assistance of a single bond.
|
Molecular geometry |
Bent |
|
Electronic geometry |
Tetrahedral |
|
Hybridization |
sp3 |
|
Bond angle |
92.1º |
|
Total valence electrons |
8 |
|
Formal charge |
0 |
Hydrogen Sulfide Preparation
Hydrogen sulfide is most regularly acquired by its detachment from acrid gas, which is petroleum gas with a high substance of H
2S. It can likewise be delivered by treating hydrogen with liquid natural sulfur at around 450 °C. Hydrocarbons can fill in as a wellspring of hydrogen in this process.
Sulfate-lessening (resp. sulfur-decreasing) microorganisms produce usable energy under low-oxygen conditions by utilizing sulfates (resp. basic sulfur) to oxidize natural mixtures or hydrogen; this produces hydrogen sulfide as a side-effect.
We can produce hydrogen sulfide by treating ferrous sulfide with a strong acid like HCl in standard lab preparation. A standard lab arrangement is to treat ferrous sulfide with a solid corrosive in a Kipp generator:
FeS + 2 HCl → FeCl2 (l) + H2S (g)
Most metals and non-metals sulfides after exposure to H2O liberate Hydrogen sulfide. For use in subjective inorganic investigation, thioacetamide is utilized to create H2S, the reaction is as follows:
CH3C(S) N H2 + H2O (l) → H2S + CH3C(O)NH2
Thioacetamide Water Hydrogen sulfide Acetamide
Many metal and nonmetal sulfides, for example, aluminium sulfide, phosphorus pentasulfide, silicon disulfide free hydrogen sulfide upon openness to water:
6 H2O + Al2S3 → 3 H2S + 2 Al(OH)3
This gas is likewise delivered by warming sulfur with strong natural mixtures and by diminishing sulfurated natural mixtures with hydrogen.
Water warmers can help the transformation of sulfate in water to hydrogen sulfide gas. This is expected to giving a warm climate reasonable to sulfur microscopic organisms and keeping up the response that connects sulfate in the water and the water warmer anode, which is generally produced using magnesium metal.
Hydrogen Sulfide Uses
The fundamental utilization of hydrogen sulfide is a forerunner to basic sulfur. A few organosulfur compounds are delivered utilizing hydrogen sulfide. These incorporate methanethiol, ethanethiol, and thioglycolic acid.
After joining with soluble base metal bases, hydrogen sulfide converts to salt hydrosulfides, for example, sodium hydrosulfide and sodium sulfide:
H2S + NaOH → NaSH + H2O
Sodium Hydroxide Sodium Hydrosulfide
On the further reaction of NaSH with NaOH, we get the following compound:
NaSH + NaOH → Na2S + H2O
Sodium Sulfide
Fact: These mixtures are utilized in the paper-making industry. In particular, salts of SH− break connections among lignin and cellulose segments of mash in the Kraft process.
Reversibly sodium sulfide within the sight of acids transforms into hydrosulfides and hydrogen sulfide; this provisions hydrosulfides in natural arrangements and is used in the creation of thiophenol.
Hydrogen Sulfide Phase Diagram
Hydrogen sulfide is a gas at STP conditions. However, at low temperature and/or high pressures the gas turns to a liquid or a solid state.
The hydrogen sulfide phase diagram describes the detailed phase behaviour with changes in temperature and pressure.
The below graph between the critical point and the triple point shows the change in the boiling point of hydrogen sulfide point with changes in pressure. Also, it shows the saturation pressure with changes in temperature:
Observations
At the critical point, no change in state occurs when its pressure is increased or if heat is added.
Here, the triple point of a substance (hydrogen sulfide) is the temperature and pressure at which the three phases viz: gas, liquid, and solid coexist in thermodynamic equilibrium.
Hydrogen Sulfide Applications
Hydrogen sulfide is utilized to isolate deuterium oxide, or hefty water, from ordinary water through the Girdler sulfide measure.
Researchers from the College of Exeter found that cell openness to limited quantities of hydrogen sulfide gas can forestall mitochondrial harm.
At the point when the cell is focused on illness, proteins are brought into the cell to deliver limited quantities of hydrogen sulfide. This examination could have further ramifications on forestalling strokes, coronary illness, and arthritis.
A suspended liveliness-like state has been prompted in rodents with the utilization of hydrogen sulfide, bringing about hypothermia with an attending decrease in metabolic rate. Oxygen request was likewise diminished, along these lines ensuring against hypoxia. Furthermore, hydrogen sulfide has been appeared to diminish irritation in different situations.