sérum

Sýrum is an Icelandic term that can arise as a grammatical form of sýra, the word for acid in chemistry. In everyday Icelandic usage, sýra is the core noun for acid, while sýrum may appear as a case form (for example, in phrases referring to abundance or possession of acids) depending on sentence structure. In English and other languages, acids are simply called acids, with Icelandic translations used in the appropriate grammatical form.

In chemistry, acids are substances that increase the concentration of hydrogen ions in solution according to the Bronsted-Lowry definition, or that accept electron pairs according to the Lewis definition. When dissolved in water, acids typically yield pH values below 7 and turn blue litmus paper red. They often have a sour taste and are corrosive, requiring careful handling.

Acids are classified by strength as strong or weak. Strong acids dissociate completely in water, producing a high concentration of hydronium ions, while weak acids dissociate only partially. Notable examples include hydrochloric acid (HCl), sulfuric acid (H2SO4), and nitric acid (HNO3). Weak acids include acetic acid (CH3COOH) and citric acid. Acids can be polyprotic, donating more than one proton in successive steps.

Common applications include chemical synthesis, metal processing, digestion in biology, and various cleaning and food-related processes (for example, citric or acetic acid in foods). Safety is a priority: acids are typically highly corrosive and can cause severe chemical burns; appropriate containment, PPE, and ventilation are essential.

See also: acid (chemistry); Arrhenius, Brønsted–Lowry definitions; pH scale.