What Is The Difference Between Sulphuric Acid And Sulphurous Acid

Difference between sulphuric acid and sulphurous acid is discussed in this article. Sulphuric acid is a highly corrosive strong mineral acid with the molecular formula H2SO4. It is soluble in water at all concentrations. Sulphuric acid is produced from sulphur, oxygen, and water vapor. In general, the production of sulphuric acid starts by burning elemental sulfur as shown below:

S(s) + O2(g) → SO2(g)

SO2(g) + H2O(l) → H2SO4(aq)

It's a clear, white colorless liquid with a mild and ephemeral nature. It has a solid sulphurous gas odor that burns.

What is the Difference Between Sulphuric Acid and Sulphurous Acid?

Sulphurous acid, also known as sulfur (IV) oxide, is a chemical compound with H2SO3. Sulphurous acid is a weak to intermediate strength acid that forms a conjugate base with bisulfite ion in solution. It has a pungent and suffocating odor, but the smell cannot detect it.

Sulphuric acid has a higher molecular weight. It is a much more potent oxidant than sulphurous anhydride, and it reacts with strong bases to produce sulphates.

Sulphuric acid has both oxidizing and reducing capabilities and its acidic features. As a result, it reacts with both metals and non-metals; like other acids, it reacts with metals to produce hydrogen gas and the metal's corresponding salt.

Sulphuric acid Uses VS Sulphurous Acid Uses

Sulphuric acid is used in the lead chamber process to produce chlorine and remove hydrogen sulfide from petroleum.

It is also used as an electrolyte in lead-acid batteries along with water. Sulphurous acid can be made by burning sulphur powder with oxygen or air to form sulfur dioxide gas which is then oxidized to sulfur trioxide gas.

On the other hand, sulphurous oxide is used in the making of sulphuric acid. It is also used to make an organic compound known as methanol peroxide, a chemical with various uses, including breaking down harmful substances in soil and purifying water.

Sulphuric acid is more reactive than sulphurous acid due to two oxygen atoms that are closer to the sulphur atom in sulphuric acid. Sulphurous acid is also less soluble in water compared to sulphuric acid.

Physical Properties of Sulphuric Acid and Sulphurous Acid

The physical properties of sulphuric acid are as follows: Sulphuric acid is a clear liquid with no color.

Sulphurous acid is a colorless gas at room temperature except for the ochreous brown fumes produced when it reacts with contact materials like carbon or copper.

Sulphuric acid is more reactive than sulphurous acid due to two oxygen atoms that are closer to the sulphur atom in sulphuric acid.

Sulphuric acid is denser than sulphurous acid. Sulphuric acid has an oily appearance, and its density is 1.84 g/cm³, which means it is heavier than water, which has a density of 1 g/cm³. Sulphurous acid is lighter than air and has an average density of 0.0012 g/cm³.

Sulphuric Acid: Molecular Weight = 98.078g/mol; Density = 1.84g/cm³

Sulphurous Acid: Molecular Weight = 62.067g/mol; Density = 0.0012g/cm³

Cons of Sulphuric Acid and Sulphurous Acid

Sulphuric acid is more reactive than sulphurous acid, and it can react with skin and other tissue that come into contact with this compound. Sulphuric acid has a corrosive effect on tissues; therefore, exposure of the eyes, throat, and stomach to this acid should be avoided since there may be irritation or corrosion of such areas.

On the other hand, Sulphurous acid is not very reactive, but it has a toxic effect on humans. It can cause damage to the respiratory system, and it has an irritating effect on the mucous membranes of the airways, which causes inflammation.

Conclusion

Thus, it can be concluded that there are many differences between sulphuric acid and sulphurous acid, starting with the structure of each compound to their physical properties like molecular weight, density, and boiling point, among others.

Sulphuric acid has a higher molecular weight, and it can be stored in glass bottles, while sulphurous acid cannot be stored in glass containers.

They also have different chemical properties, with sulphuric acid having an oxidation state of +6. In contrast, sulphurous acid has only one oxygen atom, which is closer to the sulphur atom than the other oxygen atom found in the sulphuric acid. They have very different physical properties, with denser and heavier sulphuric acids than sulphurous acid. It has a boiling point of ℃ which is higher than the boiling point of 149℃ for sulfurous acid.