Hydrohalogenowe

Hydrohalogenowe refers to chemical species containing a hydrogen atom bonded to a halogen atom (fluorine, chlorine, bromine, iodine; astatine is sometimes considered). The simplest members are the hydrogen halides HX, where X is F, Cl, Br or I. When dissolved in water, these compounds form hydrohalic acids known as hydrofluoric, hydrochloric, hydrobromic, and hydroiodic acids.

In terms of physical properties and acidity, HF has a relatively high boiling point and is a liquid at room temperature, while HCl, HBr and HI are gases at room temperature and pressure. In aqueous solution, HCl, HBr and HI are strong acids, whereas HF is a weak acid due to extensive hydrogen bonding and low dissociation. The common order of acidity in water is HI > HBr > HCl > HF.

Reactivity and applications: Hydrogen halides participate in a wide range of reactions. They react with water to form the corresponding hydrohalic acids, and with metals to yield metal halides and hydrogen gas. In organic chemistry, HX adds to alkenes and alkynes in hydrohalogenation, producing alkyl halides; the reaction generally follows Markovnikov regioselectivity, with variations under radical or peroxide conditions for HBr.

Production and safety: Industrially, hydrohalogenic acids are produced by direct combination of hydrogen gas with the corresponding halogen gas (for example, H2 + Cl2 → 2 HCl) or by processes that release HX from halide-containing materials. They are highly corrosive and react with many materials; HF is especially hazardous due to its ability to penetrate tissue and interact with calcium in bone, necessitating stringent safety measures and specialized handling materials.