1. Meaning difference: fuming sulfuric acid

Fuming sulfuric acid, also known as a sulfuric acid solution of sulfur trioxide. Colorless to light brown viscous smoky liquid, its density, melting point, and boiling point vary depending on the SO3 content. When it is exposed to the air, the volatile SO3 and water vapor in the air form small droplets of sulfuric acid and smoke, so it is called fuming sulfuric acid.

Concentrated sulfuric acid, commonly known as bad water, with the chemical formula H ₂ SO ₄, is a highly corrosive strong mineral acid. Concentrated sulfuric acid refers to a sulfuric acid solution with a mass fraction greater than or equal to 70%.

Fuming sulfuric acid

2. Different intensities:

The corrosion of organic matter is stronger with fuming sulfuric acid; Sulfuric acid with low corrosion concentration on metals is stronger.

3. Different properties:

Concentrated sulfuric acid: contains a large amount of non ionized sulfuric acid molecules (acid molecules in strong acid solutions may not all ionize into ions, and the strength of the acid is relative), so concentrated sulfuric acid has special properties such as water absorption, dehydration (commonly known as carbonization, i.e. corrosiveness), and strong oxidation; In dilute sulfuric acid, the sulfuric acid molecules have been completely ionized, so they do not have the special chemical properties of concentrated sulfuric acid.

Fuming sulfuric acid: A colorless or brown oily thick fuming liquid (brown because it contains a small amount of iron ions), with a strong pungent odor, strong water absorption, and can be mixed with water in any ratio, releasing a large amount of dilution heat. So when diluting concentrated sulfuric acid, it should be slowly injected into water along the container wall and continuously stirred with a glass rod.