H2SO3 acid name

H2SO3 acid name; The chemical compound H2SO3 acid name is sulphurous acid. Sulfurous acid has not been found in solution, but it has been detected in the gas phase. However, bisulfite (or hydrogen sulfite) and sulfite are the acid’s conjugate bases. Sulfurous acid is a chemical intermediate in the process of sulphur dioxide forming acid rain.

What is Sulfurous Acid?

This acid is also known as sulphur dioxide solution, dihydrogen thiosulfate, or trioxosulphuric acid, depending on the source. It serves as a precursor to sulphur dioxide, which in turn produces acid rain (SO2).

Trioxosulfuric acid is a colourless, odourless liquid that emits a noxious sulphur odour. Tissues and metals are both corroded by them. Some of the properties that distinguish it are conjugate acid of hydrogen sulfite and sulphur oxoacid.

Sulfurous acid - A Reducing Agent or Oxidizing Agent

The chemical compound H2SO3 is sulphurous acid, which is also known as sulphuric acid. Despite the lack of evidence, sulphurous acid has been detected in the gaseous phase.

There are several conjugate bases for this enigmatic acid, including bisulfite (or hydrogen sulfite), anions, and sulfite, as well as other less common compounds.

Sulfur dioxide dissolves in water to form a weak and unstable acid. Sulfur dioxide molecules have been detected in the gaseous phase, but it is not clear how this compound is present in the solution.

As a bleaching agent, it is also a reducing agent. Consequently, the sulphurous acid compound cannot be isolated in its pure form from the aqueous solution.


Sulfuric acid has been found in the gaseous phase despite the lack of evidence. A weak and unstable acid is formed when sulphur dioxide dissolves in water. It cannot be separated from the aqueous solution because it is both a bleaching and a reducing agent.

Chronic Health Effects of H2SO3

At some point after exposure to sulphurous acid, the following long-term (chronic) health effects may begin to occur:

According to the New Jersey Department of Health and Senior Services, sulphurous acid has not been tested for its ability to cause cancer in animals.

There have been no studies done on the effects of sulphurous acid on the reproductive systems of animals.

Sulfuric acid can also irritate the lungs over the long term. Breathlessness and coughing are common symptoms in people who have been exposed to bronchitis for long periods.

In short

People who have been exposed to bronchitis for a long time are more likely to experience breathlessness and coughing. The effects of sulphurous acid on the reproductive systems of animals have not been studied.

Sulfurous Acid Formula

Sulfurous acid’s chemical formula is H2SO3. Because of the strong chemical bond between the hydrogen, oxygen, and carbon atoms, this is the sulphurous acid chemical formula.

This is also the molecular formula for sulphurous acid since it shows that one sulphurous acid molecule contains two hydrogen atoms, one sulphur atom, and three oxygen atoms.

Sulfurous Acid Physical Properties

An acid that contains sulphur dioxide is called sulphurous acid, or sulphur dioxide solution. It’s not an organic acid at all. It’s a crystal-clear, colourless liquid.

:small_blue_diamond: Sulfurous Acid Physical State

Sulfurous acid is a colourless liquid in its natural state. When heated to a specific temperature, it automatically ignites and is highly soluble in water. It is an acid that is incompatible with strong bases and is therefore generally stable.

:small_blue_diamond: Sulfurous Acid Boiling Point

Sulfuric acid has a boiling point of 60 °C or 213 k.

:small_blue_diamond: Sulfurous Acid Vapor Pressure

At a temperature of about 21 °C, its vapour pressure is 1740 kPa.

:small_blue_diamond: Sulfurous Acid Weight

There are 82.07 atomic mass units in this acid’s formula.

:small_blue_diamond: Sulfurous Acid Density

Sulphurous acid is 1.03 kg/cm3 or 1.03 g/cm3 in density.

:small_blue_diamond: Sulfurous Acid Acidity

As a pH indicator, sulphurous acid is rated at 1.5. In terms of acidity, it’s neither too weak nor too strong.


Sulphurous acid spontaneously combusts and dissolves in water at a certain temperature. The incompatibility of sulfuric acid with strong bases accounts for its general stability. Its vapour pressure at 21 degrees Celsius is 1740 kPa and its boiling point is 60 degrees Celsius.

Sulfurous Acid Uses

Sulfurous acid is a powerful reducing agent. Due to its bleaching properties, it also serves as a disinfectant and deodorizer. Chlorine is toxic to some substances, including those listed above. When sulfuric acid is used to bleach these materials, they turn white.

Titration of sulfurous acid with sodium hydroxide

|Summary|Buret reading, mL|pH|Color|
|Before titration|0.00|1.25|Orange|
|First 1/2 equivalence point|11.25|1.93|Orange/Yellow|
|First equivalence point|22.49|4.91|Orange/ Yellow|
|Second 1/2 equivalence point|22.41|4.90|Orange/ Yellow|
|Second equivalence point|44.81|11.00|Blue|
|End of titration|50.00|12.16|Blue|

Sulfurous Acid Effects

Except in aqueous solutions, this acid rarely exists on its own. In normal circumstances, it is not harmful because it does not exist on its own. But sulfuric acid is formed when it is exposed to the atmosphere, and this acid has a wide range of detrimental effects.

Acid rain occurs when rain and sulfuric acid combine to form sulfuric acid. Acid rain is not only harmful to humans and animals but also to plants and other organisms.

Sulfurous Acid (H2SO3) Lewis Structure

Sulphurous acid (H2SO3) has a Lewis structure with two O–H bonds and one S–O bond. The sulphur atom also has one lone pair. To depict the Lewis structure of H2SO3, the total number of valence electrons of the atoms is taken into consideration.

H2SO3 has a sulphur atom as its central atom. Sulfur is surrounded by three oxygen atoms in this structure. The two hydrogen atoms have bonded to two oxygen atoms in single bonds.

Steps of drawing lewis structure of H2SO3

lewis structure of H2SO3

The Lewis structure of H2SO3 can be drawn in several ways. Because of the complexity of the H2SO3 molecule, nearly all of the steps can be utilised. In this way, you can learn a great deal about how to draw a proper Lewis structure.

:small_blue_diamond: Total number of electrons of the valance shells of H2SO3

:black_small_square: Valence electrons given by hydrogen atoms = 1 * 2 = 2

:black_small_square: Valence electrons given by oxygen atoms = 6*3 = 18

:black_small_square: Valence electrons given by sulfur atom = 6*1 = 6

:black_small_square: Total valence electrons = 2 + 18 + 6 = 26

:small_blue_diamond: Total valence electrons pairs

Total valance electrons pairs = σ bonds + π bonds + lone pairs at valence shells

By dividing the total number of valence electrons by two, we get the number of electron pairs. In the valence shells of H2SO3, there are a total of 13 pairs of electrons.

:small_blue_diamond: Selection of centre atom and a sketch of H2SO3 molecule

Being able to have greater valance is essential to being the central atom. So, which atom has the highest valence among hydrogen, oxygen, and sulphur? Sulfur has a maximum valence of six atoms.

The valence of hydrogen is one, while the valence of oxygen can go up to two. The sulphur atom is therefore the central atom of H2SO3. As a result, we can now draw a diagram of H2SO3 to show where the atoms are located.

:small_blue_diamond: Lone pairs on atoms

We can begin marking lone pairs on atoms after deciding on the central atom and drawing the H2SO3 molecule. A total of thirteen electron pairs must be marked on atoms, in case you forgot.

It already contains five sigma bonds. Eight (13-5) electron pair marks on atoms are all that remains.

In theory, the remaining electron pairs should be labelled on neighbouring atoms first. The outside atoms of H2SO3 are hydrogen atoms and oxygen atoms. Two electrons are the maximum number of electrons a hydrogen atom can hold in its final shell.

Hydrogen atoms already have two electrons each. Because of this, we are unable to label hydrogen atoms with the two-electron pairs.

As a result, mark the oxygen atoms with the two pairs of electrons. Remember the octave rule when marking lone pairs of numbers. There will be seven lone pairs for each of the three oxygen atoms.

:small_blue_diamond: Mark charges on atoms

An atom of sulphur has an additional +1 charge, while another atom of oxygen has a negative charge (-1). No charges exist on the other two oxygen atoms.

:small_blue_diamond: Check the stability and minimize charges on atoms by converting lone pairs to bonds

:small_blue_diamond: The best stable Lewis structure can be achieved by reducing the number of charged atoms by converting lone pairs into bonds. We can use the lone pair on the oxygen atom with a -1 charge to form a bond with the sulphur atom in H2SO3.

To Summarize

In case you’ve forgotten, there are a total of thirteen electron pairs that must be marked on atoms. Lone pairs can be converted into bonds to achieve the best possible stability in Lewis structures.

Frequently Asked Questions

Following are some frequently asked questions related to the H2SO3 acid name.

1. Is H2SO4 tetrahedral?

H2SO4, or sulfuric acid, is also a tetrahedral molecule. Sulfur is the central atom in sulfuric acid, which is surrounded by two O atoms and two OH groups.

2. What is the bond angle of H2SO3?

It has three equal-energy bonds or bonding areas, allowing it to form bonds with the C.H., oxygen, and O.H. of the molecule. Sp2 hybridization, then. SP two hybridization can produce this configuration if the bond angle is 120 degrees.

3. Is H2SO4 trigonal planar?

It is the number of electron pairs in the valence shell (bonded or non-bonded) that determines the molecule’s overall shape and structure. So, the VSEPR theory predicts that the shape will be trigonal-pyramidal because of the atoms’ tetrahedral arrangement.

4. What shape is a tetrahedral?

An example of a tetrahedron is a triangular pyramid (plural: tetrahedrons), a polyhedron with four triangular faces and six straight edges.

5. How strong is H2SO3?

Because the proton in H2SO3 H 2 S O 3 does not completely dissociate in water, it is a weak acid.

6. Why is sulfurous weak?

A weak acid, sulphurous acid (H2SO3), is different from sulphuric acid (H2SO4) in that it does not dissociate completely into H+ (H3O+) and bisulfite ions in the presence of a base such as water, indicating that the bisulfite ion is more effective at maintaining a proton.

7. Is hydroiodic acid strong or weak?

Iodide hydroxide solution is known as “hydriodic acid” (HI). It’s a potent acid that’s completely ionised in water.

8. How does sulfurous acid dissociate in water?

When sulfuric acid is mixed with water, the ion dissociation process begins immediately. Hydronium ions are formed when hydrogen ions combine with water molecules to form H3 O+.

9. Is carbonic acid hygroscopic?

Carbonic acid and calcium nitrate, both of which are hygroscopic, can be formed when HNO3 reacts with CaCO3 aerosol. Carbonic acid decomposition into CO2 and H2O is facilitated by the absorption of atmospheric water vapour by calcium nitrate.

10. What is the percent composition of H2SO3?

Sulfurous acid has a hydrogen content of 2.46 percent, a sulphur content of 39.07 percent, and oxygen content of 58.47 per cent.


Some chemical compounds are well-known because of their usefulness, while others are recognised because of their smell. The suffocating sulphurous odour makes it easy to spot sulphurous acid.

The chemical formula of sulfuric acid is H2 SO3. Soda ash is a byproduct of dissolving sulphur dioxide (SO2) in water. It is an oxoacid because it contains oxygen atoms in its chemical formula, making it less corrosive than strong acids like hydrochloric acid or sulfuric acid.

An excellent reducing agent for sulphurous acid is its ability to suck up oxygen from the air and various other sources of oxygen. It also has excellent bleaching properties.

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