Oleum (Fuming Sulphuric Acid) – H2S2O7

Fuming Sulphuric Acid is also known as Oleum Acid. It is produced by adding sulfur trioxide, SO3, to sulfuric acid. It mostly contains disulfuric acid (also called pyrosulfuric acid). Full process

It is an inorganic acid and reacts violently with water. 

Oleum Acid is available in two percentages:

  1. Oleum 23.25%
  2. Oleum 65%

2. Oleum Properties

CAS Number:


EC Number:



Chemical Safety:

Molecular Formula:

H2SO4.O3S or H2O7S2 or H2S2O7


Fuming sulphuric acid
Sulfuric acid, fuming
Oleum iodisum

Molecular Weight:

178.15 g/mol

Fuming Sulphuric Acid Density:


3. Oleum Names

4. Oleum Details - From Manufacturer

Thick fuming yellow liquid. Density 16.5 lb / gal. Very toxic by inhalation. Corrosive to metals and tissue, quickly causing severe burns. Used to make chemicals, dyes, explosives and in petroleum refining.

Sulfating and sulfonating agent, the dehydrating agent in nitrations, dyes, explosives, lab reagent.

Used in Explosive materials

As shared in the introduction, Fuming Sulphuric acid is also called Oleum. It is basically having a number greater than 1 ration to water.

For example, 10% oleum would mean 102.2% sulphuric acid.

5. 20 % Oleum Means

20 % Oleum = 100 + 0.225 * 20 (%) = 104.5 % Sulphuric Acid

6. Oleum Price

Maruti Fine Chemicals is a well known Oleum Manufacturer in India & also the dealers of Oleum – Fuming Sulphuric Acid Commercial Grade.

About Maruti Fine Chemicals

Maruti Fine Chemicals (MFC) was established in the year 2000, at Ambernath in Thane District. It is one of the leading manufacturer of high quality pure grade acids. At MFC, They consider Safety, Health and Environment protection as an integral part of their management policy. Their team of well educated and skilled staff supervises over an extremely well disciplined and knowledgeable work force.

Fore More Details: