CHEMISTRY GLOSSARY

ampere    →   amper

Ampere (A) is the SI base unit of electric current.

The ampere is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2×10^-7 newton per metre of length.

anhydrous    →   anhidrid

Anhydrous (without water) is an applied to minerals which do not contain water of crystallization or water of chemical combination. For example, strongly heated copper (II) sulphate pent hydrate (CuSO₄•5H₂O) produces anhydrous copper (II) sulphate (CuSO₄). Less stable and more dangerous to use than hydrated.

aqua regia    →   zlatotopka

Aqua regia is a mixture of one volume part of nitric acid (HNO₃) and three volume parts of hydrochloric acid (HCl). Dissolving of gold in aqua regia is described by the following equation:

arsenic    →   arsen

Arsenic was discovered by Albertus Magnus (Germany) in 1250. The origin of the name comes from the Greek word arsenikon meaning yellow orpiment. It is steel-grey, brittle semi-metal. Resists water, acids and alkalis. Tarnishes in air, burns in oxygen. Highly toxic by inhalation or ingestion. Arsenic is found in mispickel (arsenopyrite). Many of its compounds are deadly poison and used as weed killer and rat poison. Used in semiconductors. Some compounds, called arsenides, are used in the manufacture of paints, wallpapers and ceramics.

catalase    →   katalaza

Catalase is an enzyme which catalyzes the breakdown of hydrogen peroxide in the body into oxygen and water.

catalytic hydrogenation    →   katalitičko hidrogeniranje

Catalytic hydrogenation is the infusing of unsaturated or impure hydrocarbons with hydrogen gas at controlled temperatures and pressures and in the presence of a catalyst for the purpose of obtaining saturated hydrocarbons and/or removing various impurities such as sulphur and nitrogen.

Celsius    →   Celzijev stupanj

Celsius (°C) is a common but non-SI unit of temperature, defined by assigning temperatures of 0 °C and 100 °C to the freezing and boiling points of water, respectively.

asbestos    →   azbest

Asbestos is any one of a group of fibrous amphibole minerals (from the silicate group). It has widespread commercial uses because of its resistance to heat, chemical inertness., and high electrical resistance. Since 1970s short asbestos fibres have been recognized as a cause of asbestosis, a serious lung disorder, and mesothelioma, a fatal form of lung cancer. These concerns have limited its use and imposed many safety procedures when it is used.

atmosphere    →   atmosfera

1. Atmosphere is the column of air which is extending several hundred kilometers above the surface the Earth's surface. The density of this air decreases as you proceed up from the surface. The air in the atmosphere consists of 78 % nitrogen, 21 % oxygen, and 0.9 % argon. The remaining 0.1 % of the atmosphere consists of ozone, water vapor, carbon dioxide, methane, helium, and neon. The atmosphere is divided into different regions. The lowest two layers are the troposphere (the layer closest to the earth) and the stratosphere respectively. These two layers contain more than 99 % of the atmospheric molecules.

2. Standard atmosphere (atm) is an obsolete pressure and stress unit which should be discontinued. It is unit of pressure equal to the air pressure measured at mean sea level.

1 atm = 101 325 Pa

Technical atmosphere (at) is an obsolete MKpS pressure and sttress derived unit.

1 at = 98 066.5 Pa

1 atm = 1.033 227 453 at

bag filter    →   vrećasti filtar

Bag filter is a unit within a mechanical system that bellows in a bag form when air flows through, cleaning the air by collecting particles of foreign matter. This system of filtering is rated the most efficient- in a range of 92 % to 95 %. Vacuum cleaner have a cloth filter bag.

Bag filter system is an economical method of liquid filtration consisting of the pressure vessel, restrainer basket and micron rated filter bag. Liquid flow is from the inside to the outside of the bag - dirt is trapped inside the bag.