CHEMISTRY GLOSSARY

Avogadro’s law    →   Avogadrov zakon

Avogadro’s law: Equal volumes of all gases contain equal numbers of molecules at the same pressure and temperature. The law, often called Avogadro’s hypothesis, is true only for ideal gases. It was proposed in 1811 by Italian chemist Amadeo Avogadro (1776-1856).

berkelium    →   berkelij

Berkelium was discovered by Stanley G. Thompson, Albert Ghiorso and Glenn T. Seaborg (USA) in 1949. Named after Berkeley, a city in California, home of the University of California, USA. It is synthetic radioactive metal. Berkelium was made by bombarding americium with alpha particles.

base    →   baza

Historically, base is a substance that yields an OH - ion when it dissociates in solution, resulting in a pH>7. In the Brønsted definition, a base is a substance capable of accepting a proton in any type of reaction. The more general definition, due to G.N. Lewis, classifies any chemical species capable of donating an electron pair as a base. Typically, bases are metal oxides, hydroxides, or compounds (such as ammonia) that give hydroxide ions in aqueous solution.

Boltzmann constant    →   Boltzmannova konstanta

The Boltzmann constant (k or k_B) is the physical constant describing the relationship between the thermodynamic temperature and the average kinetic energy of particles in a gas. It equals the molar gas constant R divided by the Avogadro constant N_A and has the value 1.380 648 52(79)×10^-23 J/K. It is named after the Austrian physicist Ludwig Eduard Boltzmann (1844-1906).

Boyle’s law    →   Boyleov zakon

Boyle’s law (sometimes referred to as the Boyle-Mariott’s law) is the empirical law, exact only for an ideal gas, which states that the volume of a gas is inversely proportional to its pressure at constant temperature.

bromine    →   brom

Bromine was discovered by Antoine J. Balard (France) in 1826. The origin of the name comes from the Greek word bromos meaning stench. It is reddish-brown liquid with suffocating, irritating fumes. Gives off poisonous vapour. Causes severe burns. Oxidizer. Bromine occurs in compounds in sea water. It was once used in large quantities to make a compound that removed lead compound build up in engines burning leaded gasoline. Now it is primarily used in dyes, disinfectants and photographic chemicals.

Buchner flask    →   Buchnerova tikvica

Büchner flask (also known as a vacuum flask, filter flask, side-arm flask or Kitasato flask) is a thick-walled Erlenmeyer flask with a side arm to which a vacuum can be applied.

butane    →   butan

Butane is a gaseous hydrocarbon C₄H₁₀ obtained from petroleum (refinery gas or by cracking higher hydrocarbons). The fourth member of the alkane series, it has a straight chain of carbon atoms and is isomeric with 2-methylpropane, formerly called isobutene. It can easily be liquefied under pressure and is supplied into cylinders for use as a fuel gas. It is also a raw material for making buta-1, 3-diene for synthetic rubber.

californium    →   kalifornij

Californium was discovered by Stanley G. Thompson, Kenneth Street Jr. and Albert Ghiorso (USA) in 1950. Named after the State and University of California, USA. It is synthetic radioactive metal. Powerful neutron emitter. Californium was made by bombarding curium with helium ions.

catalyst    →   katalizator

Catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. Catalysts that have the same phase as the reactants are homogenous catalysts (e.g. enzymes in biochemical reactions). Those that have a different phase are heterogeneous catalyst (e.g. metals or oxides used in gas reactions).

The catalyst provides an alternative pathway by which the reaction can proceed, in which the activation energy is lower. In thus increases the rate at which the reaction comes to an equilibrium, although it does not alter the position of the equilibrium.