Typpihappaa

Typpihappaa, known internationally as nitric acid, is a mineral acid with the chemical formula HNO3. It is a highly corrosive oxidizing liquid that is colorless to yellow-tinged in commercial samples. Concentrated solutions, about 68–70% HNO3, are colorless and emit fumes; density is about 1.41 g/cm3 and the boiling point is 83 °C. It is miscible with water and readily forms nitrating mixtures with sulfuric acid.

Industrial production is dominated by the Ostwald process: ammonia is oxidized to nitrogen monoxide (NO) and nitrogen dioxide (NO2), which are absorbed in water to yield nitric acid. This route is the main source of commercial typpihappaa. Historically, other methods included reactions of nitrates with acids, but the Ostwald process is standard.

Nitric acid is a key precursor for nitrogen fertilizers and for various chemical syntheses, including production of ammonium nitrate, nitro compounds, dyes, and explosives. It is also used for metal cleaning and etching, and as an oxidizing reagent in organic and analytical chemistry.

Typpihappaa is highly corrosive to skin, eyes, and the respiratory tract. Fumes can cause severe irritation; contact may cause burns. It is a strong oxidizer and reacts violently with reducing agents, organic materials, and water. It can release toxic nitrogen dioxide on heating or decomposition. Storage requires corrosion-resistant containers and proper ventilation.

In Finnish, typpihappaa is the term for nitric acid, derived from typpi (nitrogen) and happo (acid). It is used in Finnish chemistry with standard hazardous-chemical precautions and is regulated for storage, transport, and handling.