What is the Difference Between Fuming Nitric Acid and Concentrated Nitric Acid?

The main difference between fuming nitric acid and concentrated nitric acid lies in their concentrations, fume formation, and chemical properties. Here are the key points:

• Concentration: Fuming nitric acid is a commercial grade of nitric acid with a very high concentration, typically containing 90-99% HNO3. Concentrated nitric acid, on the other hand, has a concentration of 68% or higher in water.
• Fume Formation: Fuming nitric acid forms colorless, yellowish, or brownish fumes due to its high concentration. Concentrated nitric acid usually does not form fumes, but very high concentrations may give off-white colored fumes.
• Chemical Properties: Both fuming and concentrated nitric acid are strong acids and oxidizers, contributing oxygen to reactions that may include flammable or combustible materials. They are highly corrosive and can cause severe burns to the eyes and skin upon contact. However, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%.

In summary, fuming nitric acid is a highly concentrated and fume-forming form of nitric acid, while concentrated nitric acid has a lower concentration and usually does not form fumes. Both are strong acids and oxidizers with corrosive properties.

Comparative Table: Fuming Nitric Acid vs Concentrated Nitric Acid

Here is a table comparing the differences between fuming nitric acid and concentrated nitric acid:

Fuming nitric acid is a commercial grade of nitric acid with a very high concentration and density. It contains 90-99% HNO3 and forms yellowish or brownish fumes due to dissolved nitrogen dioxide. Commercial-grade fuming nitric acid is often used in the explosives industry as it is not as volatile nor as corrosive as anhydrous nitric acid.

Concentrated nitric acid, on the other hand, has a concentration of 68% or higher HNO3 and a density of 1.35 g/cm³. It usually does not form fumes, but very high concentrations of this acid may give off off-white colored fumes. Concentrated nitric acid is a solution containing more nitric acid in less water, and it is used in various applications, such as nitration, oxidation, and as a strong acid.