CHEMISTRY GLOSSARY

accumulator    →   akumulator

Accumulator (secondary cell, storage battery) is a type of voltaic cell or battery that can be recharged by passing current through it from an external D.C. supply. The charging current reverses the chemical reactions in the cell. The common types are the lead-acid accumulator and the nickel-cadmium cell.

Acheson process    →   Achesonov proces

Acheson process is an industrial process to synthesize graphite and silicon carbide (carborundum), named after its inventor the American chemist Edward Goodrich Acheson (1856-1931). In this process, a solid-state reaction between pure silica sand (SiO₂) and petroleum coke (C) at very high temperature (more than 2500 °C) leads to the formation of silicon carbide under the general reaction:

While studying the effects of high temperature on carborundum, Acheson had found that silicon vaporizes at about 4150 °C, leaving behind graphitic carbon.

alkanes    →   alkani

Alkanes (paraffins) are acyclic branched or unbranched hydrocarbons having the general formula C_nH_2n+2, and therefore consisting entirely of hydrogen atoms and saturated carbon atoms. In the systematic chemical nomenclature alkane names end in the suffix -ane. They form a homologous series (the alkane series) methane (CH₄), ethane (C₂H₆), propane (C₃H₈), butane (C₄H₁₀), etc. The lower members of the series are gases; the high-molecular mass alkanes are waxy solid. Generaly the alkanes are fairly unreactive. They form haloalkanes with halogens when irradiated with ultraviolet radiation. Alkanes are present in natural gas and petroleum.

barrier film    →   barijerni film

Barrier film is a thin, continuous, non-porous, electrically insulating film on metal surfaces (usually comprised of oxides).

conductivity    →   vodljivost

Conductivity is a measure of the ability of a material to conduct electric current.

conductometry    →   konduktometrija

Conductometry is a volumetric analytic method in which the end of titration (equivalent point) is defined by an electric conductivity appliance.

degenerate orbitals    →   degenerirane orbitale

Degenerate orbitals are orbitals with the same energy. This degeneracy can sometimes be "lifted" by external electric or magnetic fields.

Donnan potential    →   Donnanov potencijal

Donnan potential is the electrical potential difference between two solutions separated by an ion-exchange membrane in the absence of any current flowing through the membrane

aluminium    →   aluminij

Aluminium was discovered by Friedrich Wöhler (Germany) in 1827. The origin of the name comes from the Latin word alumen meaning alum. It is soft, lightweight, silvery-white metal. Exposed surfaces quickly form protective oxide coating. Metal reacts violently with oxidants. Third most abundant element in the earth’s crust. Aluminium is the most abundant metal to be found in the earth’s crust, but is never found free in nature. Aluminium is obtained by electrolysis from bauxite. Used for many purposes from airplanes to beverage cans. Too soft in its pure form so less than 1 % of silicon or iron is added, which hardens and strengthens it.

ampere    →   amper

Ampere (A) is the SI base unit of electric current.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2×10^-7 newton per metre of length.