Description
Nitric acid is an inorganic substance and a strong oxyacid. The main component, the nitrate group, contains nitrogen in the V oxidation state. On an industrial scale, it is usually obtained by the reaction of ammonia with oxygen in the presence of a platinum-based catalyst. Pure nitric acid is a clear liquid, although it may change color if stored for a long time, taking on shades of yellow or brown, especially under the influence of temperature and light. Nitric acid emits smoke, which contains nitrogen oxide (IV) with a characteristic odor, harmful to the respiratory system. Concentrated nitric acid solution has a corrosive effect and is very chemically reactive. Its dilution is an exothermic process. Although fuming nitric acid does not burn and is resistant to impact, sparks and shocks, it can form explosive mixtures with certain substances, such as naphtha, hydrocarbons and alcohols. According to the ADR regulations, nitric acid is classified as a dangerous substance, with the number UN 2031.