CHEMISTRY GLOSSARY

neutral substance    →   neutralna tvar

Neutral substance is a substance that shows no acid or base properties, has an equal number of hydrogen and hydroxyl ions and does not change the colour of litmus-paper.

nitrate    →   nitrat

Nitrates are all compounds containing radical NO₃^- or any compound containing it, as a salt or ester of nitric acid. Fertilizers consist of sodium nitrate or potassium nitrate.

ohm    →   om

Ohm (Ω) is the SI derived unit of electric resistance. The ohm is the electric resistance between two points of a conductor when a constant difference of potential of one volt, applied between these two points, produces in this conductor a current of one ampere, this conductor not being the source of electromotive force (Ω = V/A). The unit was named after the German physicist Georg Simon Ohm (1789-1854).

oxygenation    →   oksigenacija

Oxygenation is the addition of pure oxygen to the water, to increase the dissolved oxygen concentration of the water.

electrode potential    →   elektrodni potencijal

Electrode potential is defined as the potential of a cell consisting of the electrode in question acting as a cathode and the standard hydrogen electrode acting as an anode. Reduction always takes place at the cathode, and oxidation at the anode. According to the IUPAC convention, the term electrode potential is reserved exclusively to describe half-reactions written as reductions. The sign of the half-cell in question determines the sign of an electrode potential when it is coupled to a standard hydrogen electrode.

Electrode potential is defined by measuring the potential relative to a standard hydrogen half cell

The convention is to designate the cell so that the oxidised form is written first. For example

The e.m.f. of this cell is

By convention, at p(H₂) = 101325 Pa and a(H⁺) = 1.00, the potential of the standard hydrogen electrode is 0.000 V at all temperatures. As a consequence of this definition, any potential developed in a galvanic cell consisting of a standard hydrogen electrode and some other electrode is attributed entirely to the other electrode

electrolytes    →   elektroliti

Electrolytes are substances which, when melted or dissolved in water, conduct electric current. By melting or dissolving they are dissociated into electrically charged particles (ions) which are able to conduct electric current. By passing of electric current the transfer of matter occurs. Positively charged particles (cations) travel towards the negative pole (the cathode) and negatively charged particles (the anions) travel towards the positive pole (the anode). Liquid metals, in which the conduction is by free electrons, are not usually regarded as electrolytes. Solid conductors of ions, as in the sodium-sulphur cell, are also known as electrolytes. Depending upon how it conducts electric current, matter can be divided into strong electrolytes, weak electrolytes and nonconductors.

plain salt    →   jednostavna sol

Plain salt is a salt that contains only metal ions (or ammonium ions) and acid radical. It is created when all ions of hydrogen in an acid are replaced with ions of metal (or ammonium ions).

polyvalent element    →   polivalentni elementi

Polyvalent element is a molecule which having more than one valence, for example oxygen is a divalent in H₂O, nitrogen is a trivalent in NH₃, carbon is a tetravalent in methane (CH₄).

primary alcohol    →   primarni alkohol

Primary alcohols are alcohols where the hydroxyl group is attached to a primary carbon atom. Thus, it has the general structure, RCH₂OH, where R is a hydrogen atom or an alkyl group.

reactive metal    →   reaktivni metal

Reactive metals are metals that readily combine with oxygen at elevated temperatures to form very stable oxides, for example titanium, zirconium, and beryllium. Reactive metals may also become embrittled by the interstitial absorption of oxygen, hydrogen, and nitrogen.