CHEMISTRY GLOSSARY

lime    →   živo vapno

Lime (or quicklime) is the common name for calcium oxide (CaO). It is manufactured from limestone, CaCO₃, by heating it to a high temperature (about 1 000 °C). At this temperature carbon dioxide, CO₂, is released from the limestone creating calcium oxide, CaO.

A further process involves adding water in a process known as hydrating, which produces hydrated, or slaked lime [Ca(OH)₂].

dropping mercury electrode    →   kapajuća živina elektroda

Dropping mercury electrode (DME) is a working electrode arrangement for polarography in which mercury continuously drops from a reservoir through a capillary tube (internal diameter 0.03 - 0.05 mm) into the solution. The optimum interval between drops for most analyses is between 2 and 5 s. The unique advantage to the use of the DME is that the constant renewal of the electrode surface, exposed to the test solution, eliminates the effects of electrode poisoning.

millimetre of mercury    →   milimetar živina stupca

Millimetre of mercury (mmHg) is a non-SI unit of pressure, equal to 133.322 Pa. The name is generally considered interchangeable with torr.

limestone    →   vapnenac

Limestone is a sedimentary rock composed primarily of calcium carbonate in the form of the mineral calcite.. Some 10 % to 15 % of all sedimentary rocks are limestones. Limestone is usually organic, but it may also be inorganic. Calcium carbonate may have been directly precipitated from the sea-water or by the lithification of coral reefs, marine organism shells, or marine organism skeletons.

living planet index    →   indeks života na planetu

The Living Planet Index (LPI) reflects changes in the health of the planet's ecosystems by tracking trends in nearly 8000 populations of vertebrate species. The LPI first calculates the annual rate of change for each species population in the dataset, then calculates the average change across all populations for each year from 1970, when data collection began, to 2007, the latest date for which data is available.

The Global LPI shows a decline of around 30 % from 1970 to 2007, based on 7953 populations of 2544 species of birds, mammals, amphibians, reptiles and fish.

mercury    →   živa

Mercury has been known since ancient times. The origin of the name comes from the Latin word hydrargyrum meaning liquid silver. It is heavy, silver-white metal, liquid at ordinary temperatures. Stable in air and water. Unreactive with alkalis and most acids. Gives off poisonous vapour. Chronic cumulative effects. Mercury only rarely occurs free in nature. The chief ore is cinnabar or mercury sulfide (HgS). Used in thermometers, barometers and batteries. Also used in electrical switches and mercury-vapour lighting products.

nerve poison    →   živčani bojni otrov

Nerve poison (nerve gas, agents) have had an entirely dominant role since the Second World War. Nerve poisons acquired their name because they affect the transmission of nerve impulses in the nervous system. All nerve poisons belong chemically to the group of organo-phosphorus compounds. They are stable and easily dispersed, highly toxic and have rapid effects both when absorbed through the skin and via respiration. Nerve poisons can be manufactured by means of fairly simple chemical techniques. The raw materials are inexpensive and generally readily available.

The most important nerve agents included in modern chemical weapons arsenals are:

Nerve poisons are colorless, odorless, tasteless liquids of low volatility. Antidotes are atropine sulfate and pralidoxime iodide.

Solvay’s process    →   Solvayev postupak

Solvay ’s process is an industrial process for producing sodium carbonate from sodium chloride and ammonia and carbon dioxide.

Carbon dioixide is produced by the thermal decomposition of limestone, CaCO₃(s).

Quicklime, formed as a by-product of the thermal decomposition of limestone, is treated with water to form calcium hydroxide.

Calcium hydroxide is heated with ammonium chloride to form ammonia and calcium chloride (by product).

Carbon dioxide reacts with ammonia to form ammonium carbonate.

Ammonium carbonate further reacts with carbon dioxide to form ammonium bicarbonate.

Ammonium bicarbonate then react with sodium chloride to form sodium bicarbonate.

Dry sodium bicarbonate is heated in rotary furnace to give anhydrous sodium carbonate or soda ash.

The carbon dioxide produced is recycled back into the process.

adenosine triphosphate    →   adenozin trifosfat

Adenosine triphosphate (ATP) is nucleotide that is of fundamental importance as a carrier of chemical energy in all living organisms. It consists of adenin linked to D-ribose).

amalgam    →   amalgam

Amalgams are metals alloyed with mercury. They can be solid or liquid, depending upon the mass ratio of thawed metal. Amalgam examples are gold/mercury, silver/mercury and copper/mercury all of which are used in dentistry.