CHEMISTRY GLOSSARY

zirconium    →   cirkonij

Zirconium was discovered by Martin Heinrich Klaproth (Germany) in 1789. The origin of the name comes from the Arabic word zargun meaning gold colour. It is grey-white, lustrous, corrosion-resistant metal. Exposed surfaces form oxide protective film. Zirconium is found in many minerals such as zircon and baddeleyite. Used in alloys such as zircaloy this is used in nuclear applications since it does not readily absorb neutrons. Also baddeleyite is used in lab crucibles. Used in high-performance pumps and valves. Clear zircon (ZrSiO₄) is a popular gemstone.

CO2 ion selective electrode    →   CO2 ion selektivna elektroda

The carbon dioxide ion selective electrode uses a gas-permeable membrane to separate the sample solution from the electrode internal solution. Dissolved carbon dioxide in the sample solution diffuses through the membrane until an equilibrium is reached between the partial pressure of CO₂ in the sample solution and the CO₂ in the internal filling solution. In any given sample the partial pressure of carbon dioxide will be proportional to the concentration of carbon dioxide. The diffusion across the membrane affects the level of hydrogen ions in the internal filling solution:

The hydrogen level of the internal filling solution is measured by the pH electrode located behind the membrane. The internal filling solution contains a high concentration of sodium bicarbonate (e.g. 0.1 mol/L NaHCO₃) so that the bicarbonate level can be considered constant.

water jet vacuum pump    →   vodena sisaljka

The water jet vacuum pump or vacuum aspirator is one of the most popular devices that produces vacuum in laboratories. The rapid flow of water through the device creates a vacuum in a side-arm that is connected to a vacuum application such a Buchner flask. The water jet vacuum pump creates a vacuum by means of Venturi effect named after the Italian physicist Giovanni Battista Venturi (1746–1822). The Venturi effect is the reduction in fluid pressure that results when a fluid flows through a constricted section of pipe. Water jet pumps are manufactured of glass, plastic or metal, depending on the conditions in which they are used.