CHEMISTRY GLOSSARY

alloy    →   legura

Alloys are solid solutions of metal or nonmetal in metal and are prepared in order to obtain certain properties. In this way alloys can have greater hardness, corrosion resistance or some other properties gained from the metal they are composed.

amperometry    →   amperometrija

Amperometry is determining the concentration of a material in a sample by measuring electric current passing through a cell containing the solution.

antifreeze    →   antifriz

Antifreeze is a substance added to the liquid (usually water) in the cooling systems of internal-combustion engines to lower its freezing point so that it does not solidify at sub-zero temperatures. The commonest antifreeze is ethane- 1.2-diol (ethylene glycol).

artificial honey    →   umjetni med

Artificial honey is the old synonym for invert sugar syrup.

atmospheric pressure    →   atmosferski tlak

Atmospheric pressure is the pressure exerted by weight of the air above it at any point on the earth’s surface. At sea level the atmosphere will support a column of mercury about 760 mm high. This decreases with increasing altitude. The standard value for the atmospheric pressure at sea level in SI units is 101 325 Pa.

activated charcoal    →   aktivni ugljen

Activated charcoal or activated carbon is charcoal that has been activated for adsorption by steaming or by heating in a vacuum. Charcoal is obtained by burning wood, nutshells, coconut husks or other materials. Charcoal becomes activated by heating it with steam to approximately 1000 °C in the absence of oxygen.

The chemical nature of amorphous carbon, combined with a high surface area makes it an ideal medium for the adsorption of organic chemicals. A single gram of such material can have 400 m² to 1 200 m² square meters of surface area. Activated charcoal is widely used to decolorize liquids, recover solvents, and remove toxins from water and air.

acylaction reaction    →   reakcije aciliranja

Acylaction reaction involves the introduction of an acyl group (RCO-) into a compound. An alkyl halide is reacted with an alcohol or a carboxylic acid anhydride e.g.

The introduction of an acetyl group (CH₃CO-) is acetylation, a process used for protecting -OH groups in organic synthesis.

alcohol    →   alkohol

Alcohols are compounds in which a hydroxy group, -OH, is attached to a saturated carbon atom. Smaller members are water soluble, inflammable and are useful as organic solvents and fuels.

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.

atomic spectroscopy    →   atomska spektroskopija

Atomic spectroscopy is an expensive analytical method which uses absorption (AAS), emission (AES) and fluorescent (AFS) characteristics of the analyte.