basisch

Basisch is a German term describing substances or environments with alkaline characteristics. In chemistry, basisch refers to solutions with a pH above 7 and to substances that can neutralize acids. The term is the equivalent of “alkaline” or “basic” in English. It is used in contrast to acidic (sauer) and neutral (neutral).

Chemically, bases are described by several theories. The Arrhenius definition characterizes bases as compounds that release hydroxide ions (OH−) in water. The Bronsted-Lowry definition defines bases as substances that accept protons, while Lewis theory describes bases as electron pair donors. Common bases include sodium hydroxide (NaOH) and potassium hydroxide (KOH), which are strong bases, and ammonia (NH3), which is weaker but still basic.

Properties and safety: bases typically have high pH values and can be caustic. They react with acids to form salts and water in neutralization reactions. Handling basische substances often requires protective equipment, as they can cause chemical burns and damage to skin or eyes. They are incompatible with strong oxidizers and some metals.

Applications and context: basisch substances are used for pH control in chemical synthesis, water treatment, cleaning products, and industrial processes. In agriculture, liming acidic soils with basische materials raises soil pH to improve nutrient availability. In geology, the term basisch also describes rocks with basaltic (low-silica, magnesium- and iron-rich) compositions, in contrast to acidic or felsic rocks.

See also: pH, acid-base theory, alkaline.