CHEMISTRY GLOSSARY

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

autocatalysis    →   autokataliza

Autocatalysis is a reaction in which its product can act as a catalyst. Oxalate oxidation with permanganate in an acid solution is a slow reaction

Mn²⁺-ions catalyse this reaction. When enough Mn²⁺-ions are created, the reaction occurs instantly.

automatic burette    →   automatska bireta

Automatic burette is used for series of tests. It is connected with a bottle which contains the titration solution. The air is pumped into the bottle by a small rubber air pump, created the pressure in the bottle which the rises the solution to the top of burette. When the the burette is full, the valve is released, the pressure in the bottle falls and the burette automatically sets itself to zero. Work with automatic burettes is by far faster and the consumption of standard solution is smaller.

base    →   baza

Historically, base is a substance that yields an OH - ion when it dissociates in solution, resulting in a pH>7. In the Brønsted definition, a base is a substance capable of accepting a proton in any type of reaction. The more general definition, due to G.N. Lewis, classifies any chemical species capable of donating an electron pair as a base. Typically, bases are metal oxides, hydroxides, or compounds (such as ammonia) that give hydroxide ions in aqueous solution.

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.

buffer capacity    →   puferski kapacitet

Buffer capacity is number of moles of a strong acid or a strong base needed to change pH of 1 dm³ of buffer solution for pH unit.

californium    →   kalifornij

Californium was discovered by Stanley G. Thompson, Kenneth Street Jr. and Albert Ghiorso (USA) in 1950. Named after the State and University of California, USA. It is synthetic radioactive metal. Powerful neutron emitter. Californium was made by bombarding curium with helium ions.

beryllium    →   berilij

Beryllium was discovered by Friedrich Wöhler (Germany) and independently by A. B. Bussy (France) in 1828. The origin of the name comes from the Greek word beryllos meaning mineral beryl; also called glucinium from the Greek word glykys meaning sweet. It is steel-grey metal. It resists attack by concentrated nitric acid, has excellent thermal conductivity and is nonmagnetic. At ordinary temperatures, it resists oxidation in air. Beryllium and its salts are toxic and should be handled with the greatest of care. Beryllium is found mostly in minerals like beryl [AlBe₃(Si₆O₁₈)] and chrysoberyl (Al₂BeO₄). Pure beryllium is obtained by chemically reducing beryl mineral. Also by electrolysis of beryllium chloride. Its ability to absorb large amounts of heat makes it useful in spacecraft, missiles, aircraft, etc. Emeralds are beryl crystals with chromium traces giving them their green colour.

bismuth    →   bizmut

Bismuth was discovered by Claude Geoffroy (France) in 1753. The origin of the name comes from the German words Weisse Masse meaning white mass; now spelled wismut and bisemutum. It is hard, brittle, steel-grey metal with a pink tint. Stable in oxygen and water. Dissolves in concentrated nitric acid. Bismuth can be found free in nature and in minerals like bismuthine (Bi₂S₃) and in bismuth ochre (Bi₂O₃) Main use is in pharmaceuticals and low melting point alloys used as fuses.

carboanhidrase    →   karboanhidraze

Carboanhidrase is an enzyme that catalyzes creation or decomposition of carbonic acid, regulates proportion of carbon dioxide and carbonic acid in the blood plasma.