Nitration reactions are chemical processes that introduce a nitro group (-NO2) into an organic molecule, typically an aromatic compound. This reaction is commonly achieved using a mixture of concentrated nitric acid (HNO3) and concentrated sulfuric acid (H2SO4), which generates the nitronium ion (NO2+), the active nitrating species. The nitration process is important in organic chemistry as it modifies the properties of the aromatic compound, allowing for further chemical reactions. Common examples include the nitration of benzene to form nitrobenzene, which is a precursor for various dyes, explosives, and pharmaceuticals.