Sulfuric Acid

Last Updated: April 28, 2024

Sulfuric Acid

Sulfuric acid is a powerful substance that plays a big role in the world of chemistry. It’s a covalent compound, which means it’s made up of atoms that share electrons to stick together. This clear, colorless liquid is known for its unique ability to react with other substances, making it super important in making lots of things we use every day.

What is Sulfuric Acid?

Sulfuric acid is a strong acid that’s used in lots of different ways, from making batteries to cleaning metals. Its formula is H₂SO₄, which means it has two hydrogen atoms, one sulfur atom, and four oxygen atoms all bonded together. This makes it a powerful chemical that can react with many other substances, making it super important in various industries. It’s also known for being really good at dissolving things, which is why it’s used so much in chemistry and manufacturing.

Chemical Names and Formulas

Property Value
Formula H₂SO₄
Hill formula H₂O₄S
Name Sulfuric acid
Alternate names Anhydrous sulfuric acid, Dihydrogen sulfate, Oil of vitriol, Sulphuric acid

Structure of Sulfuric Acid

Structure of Sulfuric Acid (H₂SO₄)

Sulfuric acid is a chemical compound with a complex and interesting structure. It has the chemical formula H₂SO₄. This means it is made up of two hydrogen atoms (H), one sulfur atom (S), and four oxygen atoms (O). The structure of sulfuric acid can be thought of as a central sulfur atom surrounded by four oxygen atoms in a tetrahedral arrangement. Two of these oxygen atoms are double-bonded to the sulfur atom, and the other two are single-bonded but also attached to hydrogen atoms.This arrangement makes sulfuric acid a very strong acid. It’s able to donate two protons (the hydrogen atoms) when it reacts with other substances. This ability to give away protons easily makes it a very important and widely used chemical in many industries. Its structure is key to its reactivity and usefulness in making a wide variety of products.

Preparation of Sulfuric Acid

Sulfuric acid is made using a method called the Contact Process. This process involves a few key steps. First, sulfur (S) is burned in air to create sulfur dioxide (SO₂). This is represented by the equation:

2S + O₂ → SO₂.

Next, the sulfur dioxide is mixed with more oxygen (O₂) in the presence of a catalyst, typically vanadium(V) oxide (V₂O₅). This helps convert the sulfur dioxide into sulfur trioxide (SO₃), shown by the equation:

2SO₂ + O₂ → 2SO₃ (in the presence of V₂O₅)

Once sulfur trioxide is formed, it’s not directly combined with water to make sulfuric acid because that reaction is too violent. Instead, the sulfur trioxide is first absorbed into a pre-existing concentration of sulfuric acid. This forms oleum (H₂S₂O₇), which is then carefully diluted with water to form sulfuric acid (H₂SO₄). The final step can be represented by the equation:

H₂S₂O₇ + H₂O → 2H₂SO₄

This careful process allows for the production of highly concentrated sulfuric acid, which is essential for many industrial applications.

Physical Properties of Sulfuric Acid

Property Description
Appearance Colorless, oily liquid
Odor Odorless
Molecular Weight 98.079 g/mol
Density 1.84 g/cm³ at 20°C
Melting Point 10°C (50°F)
Boiling Point 337°C (639°F)
Solubility in Water Completely soluble, releases heat upon mixing
pH Highly acidic (pH < 1 for concentrated solutions)
Viscosity High, varies with concentration
Conductivity Good conductor of electricity due to ionization in water

Chemical Properties of Sulfuric Acid

Strong Acid

Sulfuric acid is a very strong acid. It can donate two protons (H⁺ ions) in reactions. This makes it very reactive with bases and capable of causing burns.


It has the ability to absorb water from the air. This property makes it useful for drying out substances.

Dehydrating Agent

Sulfuric acid can remove water from other compounds. For example, when it reacts with sugar (C₁₂H₂₂O₁₁), it removes water, leaving a black mass of carbon and releasing water vapour.

Equation: C₁₂H₂₂O₁₁ + H₂SO₄ → 12C + 11H₂O + Heat

Exothermic Reactions

Mixing sulfuric acid with water releases a lot of heat. This reaction should be done carefully by adding acid to water, not the other way around, to avoid splashing of the hot acid.

Oxidizing Agent

In concentrated form, sulfuric acid can act as a powerful oxidizing agent. It can take electrons from other substances, leading to oxidation. This property allows it to react with metals, non-metals, and carbon compounds, often producing sulfur dioxide (SO₂) or sulfates.

Reaction with Metals

Sulfuric acid reacts with most metals, producing hydrogen gas and metal sulfate. For example, zinc reacts with sulfuric acid to produce zinc sulfate and hydrogen gas.

Reaction with Bases

It reacts with bases (like sodium hydroxide) to form water and a salt. This reaction with sodium hydroxide (NaOH) produces water and sodium sulfate.

Equation: 2NaOH → Na₂SO₄ + 2H₂O

Sulfuric Acid (H₂SO₄) Chemical Compound Information

Chemical Identifiers

Property Value
CAS registry number 7664-93-9
Beilstein number 2037554
PubChem compound ID 1118
PubChem substance ID 24859176
SMILES identifier OS(=O)(=O)O
InChI identifier InChI=1/H2O4S/c1-5(2,3)4/h(H2,1,2,3,4)/f/h1-2H
MDL number MFCD00064589

NFPA label

Property Value
NFPA health rating 3
NFPA fire rating 0
NFPA reactivity rating 2
NFPA hazards Water reactive

Uses of Sulfuric Acid (H₂SO₄)

Uses Of Sulfuric Acid (H₂SO₄)

Manufacturing Fertilizers

Sulfuric acid is a key ingredient in making fertilizers, especially phosphoric acid and ammonium sulfate. These fertilizers help plants grow by providing them essential nutrients.

Chemical Synthesis

It’s used in producing a wide range of chemicals, including other acids, dyes, and glues. This process involves reactions where sulfuric acid helps create new compounds.

Petroleum Refining

In the oil industry, sulfuric acid helps remove impurities from gasoline and other petroleum products. This refining process ensures the fuel is clean and efficient.

Metal Processing

Sulfuric acid is used to clean metals before they are coated or plated with other metals. It removes rust and prepares the surface for further treatment.

Battery Acid

It acts as the electrolyte in lead-acid batteries, which are found in cars and other vehicles. The acid allows electricity to flow between the battery’s plates.

Water Treatment

Sulfuric acid is used in water treatment plants to adjust the pH levels of water, making it safe for drinking and use in industrial processes.

Paper Production

In the paper industry, sulfuric acid is used to separate lignin from cellulose fibers, making paper white and durable.


It plays a role in manufacturing various medicines, acting as a catalyst in the production processes of drugs and antibiotics.

Food Industry

Although used in very small amounts, sulfuric acid helps in the processing of edible oils and fats. It also acts as a preservative in some food products.

Benefits of Sulfuric Acid (H₂SO₄)

Agricultural Productivity

  • Fertilizer Production: Sulfuric acid is crucial in manufacturing fertilizers, which enhance soil nutrition and boost crop yields significantly.

Industrial Applications

  • Chemical Synthesis: It serves as a fundamental ingredient in the synthesis of various chemicals, facilitating the production of dyes, pigments, and many other industrial compounds.
  • Metal Processing: The acid’s ability to clean metal surfaces ensures better adhesion of coatings, improving the longevity and quality of metal products.

Energy Sector

  • Battery Efficiency: As the electrolyte in lead-acid batteries, sulfuric acid is essential for the storage and provision of electrical energy, particularly in vehicles and renewable energy storage systems.

Environmental Protection

  • Water Treatment: By adjusting pH levels, sulfuric acid plays a pivotal role in water purification processes, making water safe for consumption and use in industries.
  • Pollution Control: It aids in removing harmful substances from industrial emissions, contributing to cleaner air and a healthier environment.


  • Petroleum Refining: The acid helps refine petroleum products, ensuring cleaner burning fuels and reducing emissions from vehicles.
  • Paper Production: Its use in the paper industry leads to higher quality paper by removing impurities and enhancing the brightness and strength of the paper.

Healthcare and Pharmaceuticals

  • Drug Manufacturing: Sulfuric acid is used in the pharmaceutical industry to produce various medicines, helping in the fight against diseases and infections.

Food Industry

  • Food Processing: Though used in minimal quantities, it assists in the processing and preservation of certain food products, maintaining their quality and safety.

Side Effects Of Sulfuric Acid (H₂SO₄)

  • Health Hazards: Causes severe skin burns, eye damage, respiratory issues, and digestive tract harm upon contact or inhalation.
  • Environmental Impact: Can lead to water and soil pollution, contributing to ecosystem damage and soil infertility.
  • Material Corrosion: Corrodes metals and building materials, posing infrastructure risks.
  • Safety Risks: Improper handling and storage can result in accidents and exposure.


What Happens When You Add Water to Sulfuric Acid?

Adding water to sulfuric acid can cause violent reactions, emitting heat and potentially leading to splashes or explosions. Always add acid to water instead.

What Does Sulfuric Acid Do to Skin?

Sulfuric acid burns skin upon contact, causing severe chemical burns, tissue damage, and possible scarring. Immediate rinsing with water is crucial for affected areas.

What Does Sulfuric Acid Smell Like?

Sulfuric acid has a strong, pungent odor resembling burnt matches, due to the release of sulfur oxides when exposed to air, indicating its corrosive nature.

What Happens if Sulfuric Acid Touches You?

Contact with sulfuric acid results in chemical burns, skin irritation, and potential tissue damage. Immediate and thorough washing with water is necessary to mitigate injuries.

AI Generator

Text prompt

Add Tone

10 Examples of Public speaking

20 Examples of Gas lighting