CHEMISTRY GLOSSARY

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.

coal    →   ugljen

Coal is a black or brownish-black, combustible sedimentary rock, with 30 % (lignite) to 98 % (anthracite) carbon by weight, mixed with various amounts of water and small amounts of sulfur and nitrogen compounds. It is formed from plant matter that decayed in swamps and bogs that has been compressed and altered by geological processes over millions of years. Coal is primarily used as a fuel.

gunpowder    →   barut

Gunpowder (black powder) is a low explosive composed of potassium nitrate, sulphur and charcoal. Typical proportions are 6:1:1.

oersted    →   ersted

Oersted (Oe) is a non-SI unit of magnetic field (H), equal to 79.577 471 57 A/m. The unit was named after the Danish physicist and chemist Hans Christian Oersted (1777-1851).

pit coal    →   kameni ugljen

Pit coal is natural black coal that has a carbon content of 75 %-90 %. It is an important raw material in organic industry

tar    →   katran

Tar is a brown or black bituminous material, liquid or semi-solid in consistency, gained as a product of dry distillation of natural fuels like wood, or other organic materials.

diamond    →   dijamant

Diamond is the hardest known mineral (with a hardness of 10 on Mohs’ scale). It is an allotropic form of pure carbon that has crystallised in the cubic system, usually as octahedral or cubes, under great pressure. Diamond crystals my be colourless and transparent or yellow, brown or black. They are highly prized as gemstones, but also have extensive uses in industry, mainly for cutting and grinding tools. Diamonds occur in ancient volcanic pipes of kimberlite, or in river deposits that have been derived from weathered kimberlite. Industrial diamonds are being increasingly synthetically produced.

Fehling’s test    →   Fehlingova otopina

Fehling’s test is a chemical test to detect reducing sugars and aldehydes in a solution, devised by the German chemist Hermann Christian von Fehling (1812-1885). Fehling’s solution consists of Fehling’s A (copper(II) sulphate solution) and Fehling’s B (sodium tartarate solution), equal amounts of which are added to the test solution. After boiling, a positive result is indicated by the formation of a brick-red precipitate of copper(I) oxide. Methanal, being a strong reducing agent, also produces copper metal; ketones do not react. The test is now rarely used, having been replaced by Benedict’s test.

filter paper    →   filtar papir

Filter paper is a quantitative paper used for filtering and made of pure cellulose treated with hydrochloric and hydrofluoric acid. This kind of paper burns out practically without any remains (less than 0.0001 g ashes). Different types of paper are marked with numbers; qualitative bears marking 595 or 597 and quantitative 589 or 590. Dependable upon precipitate character, different types of filter paper are used:

• black band (589¹) - 100 mL of fluid flows through it in 20 s to 30 s. It is used for filtering of gelatinous precipitates.
• white band (589²) - 100 mL of fluid flows through it in 40 s to 60 s. It is used for coarse crystalline precipitates filtration.
• blue band (589³) - 100 mL of fluid flows through it in 200 s to 400 s. It is used for fine crystalline precipitates.

haematite    →   hematit

Haematite is a mineral of iron(III) oxide Fe₂O₃. It is the most important ore of iron and usually occurs in two main forms: as a massive red kidney-shaped ore and as grey to black metallic crystals known as specular iron ore. Haematite is the major red colouring agent in rocks; the largest deposits are of sedimentary origin. In industry haematite is also used as a polishing agent (jeweller’s rouge) and in paints.