CHEMISTRY GLOSSARY

aluminate    →   aluminat

Aluminate is a salt formed when aluminium hydroxide or y-alumina is dissolved in solutions of strong bases, such as sodium hydroxide. Aluminates exist in solutions containing the aluminate ion, commonly written [Al(OH)₄]^-. In fact the ion probably is a complex hydrated ion and can be regarded as formed from a hydrated Al³⁺ ion by removal of four hydrogen ions:

Other aluminates and polyaluminates, such as [Al(OH)₆]^3- and [(HO)₃AlOAl(OH)₃]^2-, are also present.

amphoteric substances    →   amfoterna tvar

Amphoteric substances can behave as acids or as bases depending upon their surroundings. So aluminium hydroxide in reaction with acids will behave as a base

and in reaction with bases it will act as an acid

Bravais lattice    →   Bravaisova rešetka

Bravais lattice is a set of points constructed by translating a single point in discrete steps by a set of basis vectors. The French crystallographer Auguste Bravais (1811-1863) established that in three-dimensional space only fourteen different lattices may be constructed. All crystalline materials recognised till now fit in one of these arrangements. The fourteen three-dimensional lattices, classified by crystal system, are shown to the bottom.

Crystal system	Bravais lattices
cubic a=b=c α=β=γ=90°
	simple cubic	body-centered cubic	face-centered cubic
tetragonal a=b≠c α=β=γ=90°
	simple tetragonal	body-centered tetragonal
orthorhombic a≠b≠c α=β=γ=90°
	simple orthorhombic	base-centered orthorhombic	body-centered orthorhombic	face-centered orthorhombic
monoclinic a≠b≠c α=γ=90°≠β
	simple monoclinic	base-centered monoclinic
hexagonal a=b≠c α=β=90° γ=120°
	hexagonal
rhombohedral a=b=c α=β=γ≠90°
	rhombohedral
triclinic a≠b≠c α≠β≠γ≠90°
	triclinic

buffer    →   pufer otopina

Buffer is a solution designed to maintain a constant pH when small amounts of a strong acid or base are added. Buffers usually consist of a fairly weak acid and its salt with a strong base. Suitable concentrations are chosen so that the pH of the solution remains close to the pK_a of the weak acid.

carboxylates    →   karboksilati

Carboxylates is a common name for all salts that carboxylic acids yield by reacting with hydroxides, carbonates, bicarbonates and other alkaline reagents.

celluloid    →   celuloid

Celluloid is a transparent highly flammable substance made from cellulose nitrate with a camphor plasticizer. It was formerly widely used as a thermoplastic material, especially for film (a use now discontinued owing to the flammability of celluloid).

chlorination    →   kloriranje

1. Chlorination is an addition or substitution of chlorine in organic compounds.

2. Chlorination is a sterilisation of drinking and swimming pool water or oxidation of undesirable impurities, using chlorine or its compounds.

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.

blast furnace    →   visoka peć

Blast furnace is a furnace for smelting of iron from iron oxide ores (hematite, Fe₂O₃ or magnetite, Fe₃O₄). Coke, limestone and iron ore are poured in the top, which would normally burn only on the surface. The hot air blast to the furnace burns the coke and maintains the very high temperatures that are needed to reduce the ore to iron. The reaction between air and the fuel generates carbon monoxide. This gas reduces the iron(III) oxide in the ore to iron.

Because the furnace temperature is in the region of 1500 °C, the metal is produced in a molten state and this runs down to the base of the furnace.

The production of iron in a blast furnace is a continuous process. The furnace is heated constantly and is re-charged with raw materials from the top while it is being tapped from the bottom. Iron making in the furnace usually continues for about ten years before the furnace linings have to be renewed.

deoxyribonucleic acid    →   dezoksiribonukleinska kiselina

Deoxyribonucleic acid (DNA) is a nucleic acid with 2-deoxy-D-ribose as the sugar in its nucleotides. DNA contains encoded genetic information, specifically templates for the synthesis of all of an organism’s proteins and enzymes.

DNA was first identified in the 1869 by Swiss chemist Friedrich Miescher (1844-1895). In 1953, American biologist James Dewey Watson (1928-) and English physicist Francis Harry Compton Crick (1916–2004) had discovered that DNA occurs in the cell as a double helix, with two long strands of the molecule wound around each other, and further that the chemical structure of the molecule dictates that adenine (A) always aligns or pairs with thymine (T), and cytosine (C) always pairs with guanine (G). It is this base pairing that allows DNA in a cell to copy itself, and transfer its information to a new cell. The diameter of the helix is 2.0 nm and there is a residue on each chain every 0.34 nm in the z direction. The angle between each residue on the same strand is 36°, so that the structure repeats after 10 residues (3.4 nm) on each strand.