H2S Boiling Point

H2S boiling point is -60°C or -76°F. Hydrogen sulfide is a colorless, odorless gas that has an unpleasant stench similar to rotten eggs. It is shipped as a contained liquid under the pressure of its own emitted vapors. Liquid density is 8.3 pounds per gallon.

hydrogen sulfide

What is Hydrogen Sulfide?

H2S (hydrogen sulfide) is an inert gas that may be dangerous when inhaled at low concentrations. Septic gas, stench damp, or manure gas are some of the more frequent terms for it. A sickeningly sweet odor is produced at large concentrations.

A person’s ability to smell the gas may be compromised to the point that they are completely ignorant of its existence at exceptionally high concentrations.

Those who have been exposed to hydrogen sulfide for a lengthy period might also suffer from olfactory exhaustion. Unlike air, hydrogen sulfide is heavier than water, therefore it tends to build up in low-lying and enclosed locations.

Bacterial breakdown or decomposition of damaged plant and animal materials, particularly when oxygen is lacking, produces hydrogen sulfide in the environment.

Natural gas and petroleum, volcanic gases, sulfur deposits, hot springs, and marshes are all places where they may be found. Sulfide gas may be generated on beaches and mudflats due to the decomposition of organic matter in the sediment. It is also found in human and animals waste, and it is a byproduct of both processes.

A byproduct of industrial processes such as pulp and paper mills, rayon manufacture and food processing, tanneries and fur-processing factories as well as oil and natural gas refineries, hydrogen sulfide is used to prepare various sulfur chemical compounds. H2S is the chemical formula for hydrogen sulfide.

H2S Compound Name

A colorless gas noted for its unpleasant “rotten egg” stench, hydrogen sulfide (H2S) is also known as sewer gas, swamp gas, stink damp, and sour damp. It is very combustible and highly poisonous, making it exceedingly hazardous.

Some of the industries that make or utilize hydrogen sulfide include:

  • Petroleum and natural gas refinery

  • Mining

  • Tanning

  • Processing of wood and paper

  • Fabrication of rayon

Sewage, manure pits, well water, oil and gas wells, and volcanoes are all places where hydrogen sulfide may be found naturally.

Hydrogen sulfide may accumulate in low-lying and confined areas, such as manholes, sewers, and underground phone vaults since it is heavier than air. Because of its presence, working in tight places may be very hazardous

The consequences of hydrogen sulfide on a worker’s health are dependent on how much and how long they breathe it in. However, even at low doses, there are several impacts. Some of the side effects include headaches, eye discomfort, and even death.

Learn how severe hydrogen sulfide exposure may be, where to look for it, and what precautions should be taken here.

Is H2S Dangerous to my Health?

Yes, it is because of the chemical asphyxiant and irritating properties of hydrogen sulfide (it will take the place of oxygen so there is not enough for someone to breathe). When it comes to low quantities, some individuals can sense it while others aren’t aware of it at all.

Some individuals are more sensitive than others to the possible consequences. The eyes, nose, throat, and respiratory system might be irritated by low doses. Breathing problems are common among asthmatics.

More severe eye and respiratory irritations, headache, dizziness, nausea, and vomiting may be caused by moderate quantities of the toxic chemical. H2S may induce loss of consciousness and even death in short bursts of high concentration.

H2S exposure usually results in complete recovery within hours or days, depending on the individual and the severity of their exposure.

Headaches, inattention, forgetfulness, and a lack of coordination are just a few of the long-term side effects that have been reported in some patients. H2S may cause weariness, nausea, dizziness, and memory loss if it is inhaled for a long time at a low level.


Hydrogen sulfide (H2S) is a chemical substance. It is a colorless chalcogen-hydride gas that is toxic, caustic, and combustible, with a rotten egg odor in trace levels. Stinkdamp is an underground mining gas word for foul-smelling hydrogen sulfide-rich gas mixes (“vapor”). In 1777, Swedish scientist Carl Wilhelm Scheele identified the chemical composition of refined hydrogen sulfide. The Royal Society of Chemistry and the International Union of Pure and Applied Chemistry no longer advocate the spelling of hydrogen sulfide.

Boiling point of H2S

Boiling Point of H2S in Kelvin

The boiling point of H2S in Kelvin is 213.2K. Hydrogen sulfide, or H2S, is a colorless gas that has the distinct smell of rotten eggs. Uses include the production of chemicals, metallurgy, and analysis.

Poorly ventilated areas are more likely than well-ventilated areas to collect it due to its weight. Even though it has a strong odor at first, it rapidly dulls the nose’s senses.

Hydrogen sulfide is a naturally occurring compound that may be found in crude oil and natural gas, as well as volcanic gases and hot springs. A bacterial breakdown of organic substances may potentially be the cause of necrosis in the body. Human and animal waste also contribute to its production.

It is used to make compounds, metals, and as an analytical reagent, among other things. If no other phase, temperature, or pressure is supplied, the gas phase values are given at 25oC /77oF / 298 K.

At room temperature, hydrogen sulfide is a gaseous compound. It is only at low temperatures and high pressures that gases turn into liquids and solids, respectively. The temperature and pressure dependence of phase behavior is seen in the hydrogen sulfide phase diagram.

The pressure dependence of the boiling point of hydrogen sulfide may be seen in the graph between the critical point and the triple point. It also indicates the temperature-dependent saturation pressure.

H2S Exposure Chart

Using an H2S exposure chart, you can see how hydrogen sulfide levels or concentrations in the air are linked to health risks for people. The worse the impact, the greater the concentration.

The exposure chart may be seen in the table below.

Concentration (ppm) Symptoms/Effects that have a short-term impact
1000-2000 Death in a matter of seconds
700-1000 Within one or two breaths, unconsciousness, “knockdown,” or abrupt collapse, the respiration ceases. Minutes later, death occurs.
500-700 Collapse within five minutes after being startled. In only 30 minutes, the eyes might be seriously damaged. Death occurs within 30-60 minutes of the start of the count.
200-300 After an hour, conjunctivitis and irritation of the respiratory tract were evident. Persistent exposure to a toxic substance may result in pulmonary edema (a buildup of fluid in the lungs).
100 Life-and-health-threatening – IDLH – Get out of the area and into a safe place. Coughing, itching eyes, and a diminished sense of smell are all symptoms of the flu. Alterations in breathing, tiredness after 15-30 minutes, and throat discomfort after one hour. Swelling in intensity over some time. After 48 hours, death is possible.
50-100 Conjunctivitis of the eyes (eye irritation and redness). After an hour, the respiratory tract becomes inflamed. Discomfort and a lack of appetite may result from using this medication.
20 Dizziness and fainting are possible side effects of anemia.
2-5 The long-term effects of exposure include nausea, tearing of the eyes, headaches, and insomnia. A common symptom of asthma is airway obstruction (bronchial constriction).
0.01 to 1.5 The odor threshold ranges (when rotten egg smell is first noticeable to some). By 3–5 ppm, the odor becomes overpowering. Odor is regarded as sweet or sickeningly sweet above a concentration of 30 ppm.
0.00011 - 0.00033 Typical concentrations in the environment

Hydrogen Sulfide Smell

Smelling like rotten eggs at low concentrations in the air, hydrogen sulfide is a colorless, combustible gas that is very toxic. It is frequently known as sewage gas, smelly damp, and manure gas. A sickeningly sweet odor is produced at large concentrations.

Here you can find how to exposure of H2S:

  • Inhaling hydrogen sulfide-contaminated air.

  • Hydrogen sulfide levels may be elevated in the vicinity of a wastewater treatment facility, a gas or oil drilling activity, a farm with manure storage or animal confinement facilities, or a landfill.

  • Hydrogen sulfide may pose a risk to workers in the oil and gas, wastewater treatment, rayon textiles, tanneries, landfills, and manure storage pit industries.

  • Hydrogen sulfide levels may be low on mudflats with oxygen-starved organic stuff in the substrate. Hydrogen sulfide has been a concern on beaches with large volumes of rotting organic material, such as seaweed.

  • Hydrogen sulfide is mildly soluble (it may dissolve) in water and can be found in geothermal springs and certain marshes. Hydrogen sulfide may be present in Washington’s municipal or well water, although it is very uncommon.

  • H2S can be formed in your mouth and digestive system, but it’s very little in concentrations that might harm you. Some foods have high sulfur levels, notable plants in the onion family, especially garlic.

Is H2S Acid or Base?

Though it is more often a Lewis acid, H2S is capable of acting as a Lewis base under certain conditions.

The H2S is a weak acid.

H 2O+ H2S ⇌ H3O+SH

Because it donates a proton to water, H2S is a Bronsted acid. In addition, it is a Lewis acid because it accepts two electrons from hydronium ion to create the O-H bond.

H2S is a Lewis base since it contains two lone pairs on the S. Protonation of H2S occurs in the presence of a strong acid, such as H2SO4.

H2S: H2SO4 → H3S + HSO4

The H2 S is behaving as a Lewis base because it is giving an electron pair to establish a bond with the H of H2SO4.

Hydrogen Sulfide Symptoms

Known as H2S, hydrogen sulfide (also known as rotten egg gas) is a colorless gas with a pungent stench. Respiratory and ocular discomfort are possible side effects of hydrogen sulfide exposure.

It may also induce apnea, coma, convulsions, dizziness, headache, weakness, irritability, and sleeplessness, as well as stomach trouble and frostbite if it’s a liquid form of the drug.

Hydrogen sulfide may cause health problems for workers who are exposed to it. The degree of exposure is determined by the dosage, duration, and nature of the task.

Many different businesses make use of hydrogen sulfide. Textiles, for example, are made using this material. Hydrogen sulfide poisoning may affect a wide range of workers, including:

  • Workers at rayon textile manufacturing factories

  • Drilling and refining personnel in the petroleum and natural gas industries.

  • Industrialists involved in the treatment of wastewater.

  • Agriculturists operate on farms with manure storage or disposal facilities.

  • Read chemical labels and Safety Data Sheets for information on hydrogen sulfide hazards if you operate in an industry that employs it.

Hydrogen sulfide exposure in the workplace may be learned more about from the resources listed below. Hydrosulfuric acid, “sewer gas,” and “sulfuretted hydrogen” are all useful search phrases for hydrogen sulfide.

How to Make Hydrogen Sulfide?

In the majority of cases, hydrogen sulfide is extracted from sour gas, which is natural gas that is rich in hydrogen sulfide (H2S). Another method is to combine hydrogen with molten sulfur at 450 degrees Celsius.

Hydrogen may be obtained from hydrocarbons in the following way:

  • Under low oxygen circumstances, sulfate-reducing (resp. sulfur-reducing) bacteria use sulfates (resp. elemental sulfur) to oxidize organic molecules or hydrogen, resulting in the production of hydrogen sulfide.

  • In a Kipp generator, ferrous sulfide is treated with a strong acid as a conventional lab preparation. FeS + 2 HCl → FeCl2 + H2S.

  • It is necessary to create H 2S from thioacetamide in qualitative inorganic analysis. CH3C(S)NH2 + H2O → CH3C(O)NH2 + H2S.

  • Hydrogen sulfide is formed when water comes into contact with metal and nonmetal sulfides, such as aluminum sulfide, phosphorus pentasulfide, and silicon disulfide. 6H2O + Al2S3 → 3 H2S + 2 Al(OH)3.

  • In addition to heating sulfur with solid organic molecules and reducing sulfurated organic compounds with hydrogen, this gas may be created.

Hydrogen sulfide gas may be produced from water sulfate by the use of water heaters. This is because the water heater anode, which is typically formed of magnesium metal, reacts with sulfate in the water and provides a heated climate that is sustainable for sulfur bacteria.

Frequently Asked Questions

Here are some FAQs related to H2S:

1. Why is H2S less flammable?

It has weaker hydrogen bonds than water. Sulfur has a lower electronegativity than oxygen. So breaking hydrogen bonds in H2S requires less energy. So H2S has a lower boiling point than water.

2. Why is H2S so hot?

Silane is heavier and has a higher boiling point. They have greater boiling temperatures than methane or silane because they are both polar and exhibit dipole-dipole forces. But water possesses hydrogen bonds, super dipole-dipole forces.

3. Is H2S’s boiling point high or low?

As with H2S, it has a higher (-60C). Hexafluorocarbons (HCl) (-85C). The boiling point is determined by molecular attraction.

4. Why is H2S less flammable than H2S?

Because H2Se is a larger molecule than H2S, the Van Der Waal forces (London forces) are greater, requiring more energy to break than H2S, resulting in H2S having a lower boiling point.

5. Why is H2S less hot than H2Se?

Vander Waals interaction rises with mass. Because H2S has the smallest mass of the three, it has the smallest van der Waals forces and hence the lowest boiling point.

6. H2O vs H2S: Why is H2

It is simpler to split HF into H+ and F- than it is to break H2O into H+ and OH-. Because S is a bigger atom than O, the H–S bond is longer and weaker than H–O.

7. Why is water so soft?

Water is a liquid at ambient temperature because hydrogen bonds between water molecules are stronger than van der Waals forces. Compared to ionic bonds, the H-bond energy was relatively low. So its melting point is lower.

8. Why is H2S vapor pressure greater than H2O?

Water has greater intermolecular interactions, higher molar heat of vaporization, a higher surface tension, and higher viscosity than H2S because hydrogen bonds are stronger than dipole forces. The number of gas molecules above the liquid is called vapor pressure.

9. Why is water so hot?

The boiling point of water is exceptionally high. Water contains oxygen and hydrogen, which may form hydrogen bonds, strong intermolecular interactions. These high intermolecular interactions lead water molecules to “stick” together, preventing gasification.

10. Why does H2Se outperform H2S?

Because Se is bigger than S, the H–Se bonds are longer in binary acids like H2S and H2Se. As a result, H2Se is a stronger acid than H2S.


Because sulfur is less electronegative than oxygen, hydrogen sulfide is less polar than water. Because of this, H2S has weak intermolecular interactions and lower melting and boiling temperatures than water. Final review session: H2Se has a higher boiling point (and hence stronger bonding) than H2S due to higher London dispersion forces. Stronger bonding in H2Se makes it a stronger acid than H2S.

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Boiling Point
Kelvin Boiling Point

Hydrogen sulfide is a colourless, odourless gas that has an unpleasant stench similar to rotten eggs. Boiling point is -60.2°C. Hydrogen sulfide (H 2S) is a chemical compound having the molecular formula H 2S.

It is a colorless chalcogen-hydride gas that is poisonous, caustic, and combustible. Trace amounts of it in the environment have a peculiar unpleasant stench that reminds one of the rotten eggs, and it is toxic and incendiary.