Nitrous acid

Nitrous Acid (HNO2) is a weak and monobasic acid known for its role in the field of chemistry. It is a polar molecule that is typically used in the production of diazonium salts from amines.

Chemical Properties

Nitrous Acid is a weak acid that partially ionizes in water to form hydronium ions (H3O+) and nitrite ions (NO2-). The acid dissociation constant (Ka) of nitrous acid is approximately 4.5 x 10^-4 at 25 degrees Celsius.

Physical Properties

In its pure form, nitrous acid is a blue or white crystalline solid. However, it is unstable and decomposes easily into nitrogen dioxide (NO2), nitric oxide (NO), and water.

Preparation

Nitrous acid is typically prepared in a laboratory setting by reacting sodium nitrite (NaNO2) with a mineral acid such as hydrochloric acid (HCl).

Uses

Nitrous acid is primarily used in organic chemistry for the diazotization of amines. This process is used to prepare diazonium salts, which are useful intermediates in the synthesis of dyes, pharmaceuticals, and other organic compounds.

Safety

Nitrous acid is a strong oxidizer and can react violently with organic materials, leading to fire or explosion. It is also corrosive and can cause burns if it comes into contact with skin or eyes.

See Also

• Nitric Acid
• Sulfuric Acid
• Hydrochloric Acid