CHEMISTRY GLOSSARY

Bronsted base    →   Bronstedova baza

Brønsted base is a material that accepts hydrogen ions in a chemical reaction.

Bronsted-Lowry’s acid-base theory    →   Bronsted-Lowryeva teorija kiselina i lužina

Brønsted-Lowry’s acid-base theory: Acid is a substance which gives a proton (protondonor) and base is a substance which accepts a proton (protonacceptor).

caramel    →   karamel

Caramel is a dark brown substance made from sugar, used to colour and flavour food, added to some liqueur as a colouring agent.

Beer’s law    →   Beerov zakon

Beer’s law (or Beer-Lambert law) is the functional relationship between the quantity measured in an absorption method (A) and the quantity sought, the analyte concentration (c). As a consequence of interactions between the photons and absorbing particles, the power of the beam is attenuated from P_o to P. Beer’s law can be written

where A is the absorbance at a given wavelength of light, ε is the molar absorbtivity or extinction coefficient (L mol^-1 cm^-1), unique to each molecule and varying with wavelength, b is the length of light path through the sample (cm), and c is the concentration of the compound in solution (mol L^-1).

biocapacity    →   biokapacitet

Biocapacity (or biological capacity) is the capacity of ecosystems to produce useful biological materials and to absorb carbon dioxide generated by humans, using current management schemes and extraction technologies. Useful biological materials are defined as those used by the human economy, hence what is considered useful can change from year to year. The biocapacity of an area is calculated by multiplying the actual physical area by the yield factor and the appropriate equivalence factor.

Yield factor is a factor that accounts for differences between countries in productivity of a given land type. Each country and each year has yield factors for cropland, grazing land, forest, and fisheries.

Equivalence factor is a productivity based scaling factor that converts a specific land type into a universal unit of biologically productive area, a global hectare (gha).

Bunsen, Robert Wilhem    →   Bunsen, Robert Wilhem

Robert Wilhem Bunsen (1811-1899) is a German chemist who held professorships at Kassel, Marburg and Heidelberg. His early researches on organometallic compound of arsenic cost him an eye in an explosion. Bunsen's most important work was in developing several techniques used in separating, identifying, and measuring various chemical substances. He also improvement chemical battery for use in isolating quantities of pure metals - Bunsen battery.

The essential piece of laboratory equipment that has immortalized the name of Bunsen was not invented by him. Bunsen improved the burner's design, which had been invented by Faraday, to aid his endeavors in spectroscopy. Use of the Bunsen burner in conjunction with a glass prism led to the development of the spectroscope in collaboration with the German physicist Gustav Kirchoff and to the spectroscopic discovery of the elements rubidium (1860) and cesium (1861).

carbonization    →   karbonizacija

Carbonization begins when you heat organic substances like wood, sugar or meat with no presence of air; they go black because of secreted carbon.

carbon    →   ugljik

Carbon has been known since ancient times. The origin of the name comes from the Latin word carbo meaning charcoal. Graphite form of carbon is a black, odourless, slippery solid. Graphite sublimes at 3825 °C. Diamond form is a clear or colored; an extremely hard solid. C60 is Buckminsterfullerine. Carbon black burns readily with oxidants. Carbon is made by burning organic compounds with insufficient oxygen. There are close to ten million known carbon compounds, many thousands of which are vital to organic and life processes. Radiocarbon dating uses the carbon-14 isotope to date old objects.

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.

cation exchange    →   kationski izmjenjivač

Cation exchange is a cationic resin has positive ions built into its structure and therefore exchanges negative ions. In the cation exchange, the side groups are ionised acidic groups, such as (-SO₃H, -COOH, -OH) to which cations H⁺ are attached. The exchange reaction is one in which different cations in the solution displace the H⁺ from the solid.