CHEMISTRY GLOSSARY

mole    →   mol

Mole (mol) is the SI base unit of amount of substance.

The mole is the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kg of carbon 12.

When the mole is used, the elementary entities must be specified and may be atoms, molecules, ions, electrons, other particles, or specified groups of such particles. In this definition, it is understood that the carbon 12 atoms are unbound, at rest and in their ground state.

Neel temperature    →   Neelova temperatura

Néel temperature (T_N) is the critical temperature above which an antiferromagnetic substance becomes paramagnetic. The phenomenon was discovered around 1930 by the French physicist L.E.F. Néel (1904-2000).

nonelectrolyte    →   neelektrolit

Nonelectrolytes are substances which in solutions do not dissociate into ions and they do not conduct electric current.

oligomer    →   oligomer

Oligomer is a substance consisting of molecules of intermediate relative molecular mass (molecular weight), the structure of which essentially comprises the multiple repetitions of units derived, actually or conceptually, from molecules of low relative molecular mass. In contrast to a polymer, the properties of an oligomer can vary significantly with the removal of one or a few of its units.

Nernst’s division law    →   Nernstov zakon razdjeljenja

Nernst’s division law states that a substance is divided between two solvents in a way that proportion of concentrations of that substance is at certain temperatures constant, under the condition that both solvents are in the same molecular state. Division coefficient is a proportion of substance concentration in solvents A i B at a defined temperature.

Appearance of division is used for substance extraction.

open system    →   otvoreni sustav

Open system is a system which can exchange matter and energy with the environment.

optical activity    →   optička aktivnost

Optical activity is the ability of a chiral molecule to rotate the plane of plane-polairzed light. Molecules of an optically active substance cannot be superimposed on their own mirror images, just as your left hand cannot be superimposed on your right when both are held palm-down.

organic solvent    →   organsko otapalo

Organic solvent is an organic liquid in which organic (non-polar) substances melt.

organoleptic testing    →   organoleptičko ispitivanje

Organoleptic testing of matter is a testing of matter and material using the senses of sight, smell, taste and touch, used usually when buying groceries.

overpotential    →   prenapon

Overpotential (η) is a potential that must be applied in an electrolytic cell in addition to the theoretical potential required to liberate a given substance at an electrode. The value depends on the electrode material and on the current density.