CHEMISTRY GLOSSARY

Boyle’s law    →   Boyleov zakon

Boyle’s law (sometimes referred to as the Boyle-Mariott’s law) is the empirical law, exact only for an ideal gas, which states that the volume of a gas is inversely proportional to its pressure at constant temperature.

Bunsen burner    →   Bunsenov plamenik

Bunsen burner is a standard source of heat in the laboratory. German chemist Roberts Bunsen (1811-1899) improved the burner's design, which had been invented by Faraday, to aid his endeavors in spectroscopy. The Bunsen burner has a vertical metal tube through which a fine jet of fuel gas is directed. Air is drawn in through airholes near the base of the tube and the mixture is ignited and burns at the tube’s upper opening. The flow of this air is controlled by an adjustable collar on the side of the metal tube. When the whole is closed a yellow safety flame is displayed. Where as when the whole is open it displays a power dull blue flame with a faint blue outer flame with a vibrant blue core used u for combustion and hearting. The flame can reach temperatures of 1 500 °C.

catalyst    →   katalizator

Catalyst is a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change. Catalysts that have the same phase as the reactants are homogenous catalysts (e.g. enzymes in biochemical reactions). Those that have a different phase are heterogeneous catalyst (e.g. metals or oxides used in gas reactions).

The catalyst provides an alternative pathway by which the reaction can proceed, in which the activation energy is lower. In thus increases the rate at which the reaction comes to an equilibrium, although it does not alter the position of the equilibrium.

chemisorption    →   kemisorpcija

Chemisorption is a binding of a liquid or gas on the surface or in the interior of a solid by chemical bonds or forces.

chlorination    →   kloriranje

1. Chlorination is an addition or substitution of chlorine in organic compounds.

2. Chlorination is a sterilisation of drinking and swimming pool water or oxidation of undesirable impurities, using chlorine or its compounds.

Charles’ law    →   Charlesov zakon

The volume of a fixed mass of gas at a constant pressure expand by the constant fraction of its volume at 0 °C. For each Celsius or kelvin degree its temperature is raised. For any ideal gas fraction it is approximately 1/273. This can be expressed by the equation

were V° is the volume at 0°C and V is its volume at t°C.

This is equivalent to the statement that the volume of a fixed mass of gas at a constant pressure is proportional to its thermodynamic temperature

This law also know as Gay-Lussac’s law.

An equation similar to the one given above applies to pressures for ideal gases:

chemical equation    →   kemijska jednadžba

Chemical equation is a way of denoting a chemical reaction using the symbol for the participating particles (atoms, molecules, ions, etc.); for example,

The single arrow is used for an irreversible reaction; double arrows are used for reversible reactions. When reactions involve different phases, it is usual to put the phase in brackets after the symbol.

The numbers a, b, c, and d, showing the relative numbers of molecules reacting, are called the stoichiometric coefficients. The convention is that stoichiometric coefficients are positive for reactants and negative for products. If the sum of the coefficients is zero, the equation is balanced.

coal tar    →   ugljeni katran

Coal tar is a material obtained from the destructive distillation of coal in the production of coal gas. The crude tar contains a large number of organic compounds (e.g. benzene, naphthalene, methylbenzene, etc.), which can be separated by fractional distillation.

covalent compound    →   kovalentni spoj

Covalent compound is a compound made of molecules - not ions, such as H₂O, CH₄, Cl₂. The atoms in the compound are bound together by shared electrons. Also called a molecular compound.

cyanogen    →   cijan

Cyanogen is a colourless gas, (CN)₂ with a pungent odour. The compound is very toxic. It my be prepared in the laboratory by heating mercury (II) cyanide.