ACIDi

Acidi is the Italian plural form of acido; in English, the corresponding term is acids. Acids are substances that, in broad terms, donate protons or accept electron pairs in chemical reactions. In the Arrhenius framework, acids increase hydrogen ion concentration in aqueous solution, while bases increase hydroxide. The Brønsted–Lowry definition focuses on proton donation, and the Lewis view emphasizes acid as an electron-pair acceptor. These theories together describe the behavior of acids in many contexts.

Acids are commonly classified as strong or weak, depending on the degree of dissociation in water, and as monoprotic, diprotic, or polyprotic, according to the number of protons they can donate. They are also divided into inorganic acids, such as hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3), and organic acids, such as acetic acid (CH3CO2H) and citric acid (C6H8O7). Acids form conjugate bases after donating protons, a concept central to acid–base chemistry.

Typical properties include a sour or sharp taste, corrosiveness, and the ability to turn blue litmus red. They react with metals to release hydrogen gas and with carbonates to produce carbon dioxide. Acids participate in many catalytic and synthetic processes and influence the pH of solutions, tissues, and environmental systems.

Acids occur widely in nature and industry. They are essential in digestion, catalysis, ore processing, fertilizer production, food preservation, and biological systems where pH regulation and metabolite balance depend on acid–base chemistry. Safety considerations center on corrosivity and environmental impact, necessitating proper handling and containment.