Sulfuric Acid 98%
Commercial concentrated sulfuric acid supplied at 98% for nitration and sulfonation duty, metal pickling, dehydration, and general process chemistry.
What is Sulfuric Acid 98%?
Sulfuric acid is the highest-tonnage industrial chemical in the world and the workhorse of process chemistry. At 98% it is a dense, colourless to pale yellow oily liquid that is both a strong diprotic acid and a powerful dehydrating agent.
Those two properties are usually used together. In nitration it supplies the protons that generate the nitronium ion and simultaneously removes the water that would otherwise stop the reaction — which is why mixed acid, rather than nitric acid alone, is the standard nitrating system.
At Chelora Chemicals, 98% sulfuric acid is supplied to a controlled assay with iron, chloride, and residue on ignition held to specification, since trace metals and halides carry directly into product quality in nitration, sulfonation, and pickling service.
- Appearance
- Colourless to pale yellow oily liquid
- Odour
- Odourless (fumes are irritating)
- Solubility
- Miscible with water — strongly exothermic
- Function
- Mineral acid / dehydrating agent
- Grade
- Commercial 98%
Formula diagram
A sulfur centre with two double-bonded oxygens and two acidic hydroxyls
- Molecular formulaH2SO4
- Molecular weight98.08 g/mol
- IUPAC nameSulfuric acid
- Functional groupsDiprotic mineral acid
- CAS number7664-93-9
Technical product information
Standard specification for Chelora Chemicals' commercial 98% Sulfuric Acid 98%. Custom-grade and bulk specifications are available on request.
| Chemical name | Sulfuric Acid |
|---|---|
| Synonyms | SA, H2SO4, Oil of vitriol, Battery acid (dilute) |
| CAS number | 7664-93-9 |
| Molecular formula | H2SO4 |
| Molecular weight | 98.08 g/mol |
| Assay (H2SO4) | 98.0% min |
| Appearance | Clear, colourless to pale yellow oily liquid |
| Density (20°C) | 1.83–1.84 g/cm³ |
| Boiling point | approx. 338°C |
| Freezing point | approx. 3°C |
| Iron (Fe) | ≤ 50 ppm |
| Chloride (Cl) | ≤ 10 ppm |
| Residue on ignition | ≤ 0.02% |
| Packaging | 250 kg HDPE drums, 1200 kg IBC, road tanker |
Applications of Sulfuric Acid 98%
Nitration & mixed acid
Combined with nitric acid to generate the nitronium ion and absorb the water of reaction in nitroaromatic manufacture.
Sulfonation
Introduces sulfonic acid groups in dye, detergent, and surfactant intermediate synthesis.
Metal pickling & treatment
Removes oxide scale from steel and other metals before rolling, coating, or plating.
Fertiliser manufacture
Converts phosphate rock into phosphoric acid and superphosphate fertilisers.
Petroleum refining
Used as a catalyst in alkylation and in the treatment of refinery streams.
Dehydration & process duty
Applied as a drying agent for gases, an esterification catalyst, and a general process acid.
Why choose Chelora Chemicals
Every batch of Sulfuric Acid 98% is manufactured, tested, and documented to a standard that formulators and process chemists can build on with confidence — from first sample to full production volume.
Consistent purity
Assay held at 98% minimum with iron, chloride, and ignition residue verified before dispatch.
Full documentation
COA, SDS, and regulatory data supplied with every shipment.
Flexible volumes
From 250 kg drums to IBC and dedicated road tanker supply.
Technical support
Process, handling, and compliance guidance from our chemistry team.
Storage and guidelines
- 01Store in dedicated, clearly labelled, bunded tanks or containers in a cool, dry, ventilated area.
- 02Keep containers tightly closed — concentrated acid absorbs moisture from air, which dilutes it and makes it far more corrosive to steel.
- 03Protect from freezing: 98% acid begins to solidify near 3°C and expands on freezing, which can damage vessels and lines.
- 04Use appropriate materials of construction — carbon steel is acceptable for concentrated acid at low velocity, but dilute acid requires lined or alloy equipment.
- 05Segregate rigorously from water, alkalis, organic materials, oxidising agents, chlorates, carbides, and metal powders.
- 06Ensure spill containment, neutralising material, emergency showers, and eyewash stations are available at every handling point.
Handling precautions
Sulfuric acid causes severe skin burns and eye damage, and can cause blindness. Face shield, chemical goggles, acid-resistant gloves, apron, and boots are required for any transfer operation.
Always add acid to water, never water to acid. Diluting concentrated acid releases a large amount of heat very quickly, and adding water to acid can boil the surface and eject acid violently.
Contact with metals generates hydrogen, which is flammable and can form an explosive atmosphere in enclosed tanks and containers. Vent and inert storage appropriately.
Reaction with organic material, chlorates, carbides, and metal powders can be violent. Never store or transfer near incompatible materials.
In many jurisdictions sulfuric acid above a set concentration is a regulated explosives precursor with licensing, reporting, and suspicious-transaction obligations. Confirm your national requirements before ordering.
Refer to the full Safety Data Sheet for exposure limits, spill neutralisation, disposal, and first-aid measures before use.
Frequently asked questions
What does 98% sulfuric acid mean?
It is the assay: 98 grams of H2SO4 in every 100 grams of product, with the balance mostly water. Commercial concentrated acid is normally supplied at 98% because that composition is close to the maximum boiling azeotrope and is stable in storage.
Why must acid always be added to water and never the reverse?
Dilution releases a large amount of heat. Pouring acid into a large volume of water spreads that heat through the water. Pouring water onto acid concentrates the heat at the surface, which can flash the water to steam and throw concentrated acid out of the vessel.
Why is concentrated acid less corrosive to steel than dilute acid?
Concentrated sulfuric acid forms a passivating iron sulfate layer on carbon steel. Once the acid picks up water and drops below roughly 78%, that layer breaks down and attack becomes rapid, which is why keeping containers sealed against moisture matters.
What is the role of sulfuric acid in nitration?
It protonates nitric acid to generate the nitronium ion that attacks the aromatic ring, and it absorbs the water produced by the reaction. Without that dehydrating action the nitration would slow and stall.
Why does the acid look yellow or brown?
Traces of organic matter or iron picked up from equipment cause discolouration. Colour alone does not indicate off-specification assay, but it can point to contamination worth investigating for sensitive duty.
Does sulfuric acid freeze?
Yes. 98% acid begins to solidify around 3°C and expands as it does, which can rupture lines and damage vessels. Heated or insulated storage is normal in cold climates.
Why is hydrogen generation a concern?
Acid attacking metal produces hydrogen gas, which is flammable and can accumulate in the headspace of a sealed tank or drum. Proper venting and avoiding incompatible metals in the system are essential controls.
What packaging is available?
250 kg HDPE drums, 1200 kg IBCs, and dedicated road tankers. Tanker deliveries require confirmed offloading procedures and receiving-tank compatibility before dispatch.
Is sulfuric acid a regulated substance?
In many jurisdictions, yes. Concentrated sulfuric acid is controlled as an explosives precursor above a set concentration threshold, with licensing and reporting requirements for supply and possession. Confirm the rules that apply in your country before ordering.
What should be kept on hand for a spill?
Suitable neutralising material such as soda ash or lime, inert absorbent, acid-resistant PPE, and a functioning emergency shower and eyewash. Spill procedures should be written and rehearsed before the first delivery arrives.
Do you provide a Certificate of Analysis?
Yes. Every consignment ships with a Certificate of Analysis and Safety Data Sheet covering assay, density, iron, chloride, and ignition residue, together with the required transport documentation.