CHEMISTRY GLOSSARY

insulator    →   izolator

Insulator is a material in which the highest occupied energy band (valence band) is completely filled with electrons, while the next higher band (conduction band) is empty. Solids with an energy gap of 5 eV or more are generally considered as insulators at room temperature. Their conductivity is less than 10^-6 S/m and increases with temperature.

intensive property    →   intenzivno svojstvo

intensive property is a property that does not change when the amount of sample changes. Examples are density, pressure, temperature, colour.

isotherm    →   izoterma

Isotherm is a line connecting points of equal temperature on a graphic representation of a physical system.

isothermal process    →   izotermni proces

Isothermal process is a thermodynamic process in which the temperature of the system does not change.

latent heat    →   latentna toplina

Latent heat (L) is the quantity of heat absorbed or released when a substance changes its physical phase at constant temperature (e.g. from solid to liquid at the melting point or from liquid to gas at the boiling point).

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

experiment    →   eksperiment

Experiment is direct observation under controlled conditions. Most experiments involve carefully changing one variable and observing the effect on another variable (for example, changing temperature of a water sample and recording the change volume that results).

Fahrenheit scale    →   Fahrenheitova skala

Fahrenheit scale is the temperature scale in which 212 degrees is the boiling point of water and 32 degrees is the freezing point of water. The scale was invented in 1714 by the German physicist G.D. Fahrenheit (1686-1736).

32 °F = 0 °C
212 °F = 100 °C
1 °F =(5/9) °C
T(°C) = (5/9)[T(°F) - 32]
T(°F) = (9/5)T(°C) + 32

lattice energy    →   energija kristalne rešetke

Lattice energy is the energy per ion pair required to separate completely the ions in a crystal lattice at a temperature of absolute zero.

monotropy    →   monotropija

Monotropy is a type of polymorphism in which there is one stable form and all others are unstable and there is no transitional temperature between them.