What properties does beryllium exhibit?

Beryllium Be is a light gray, lightweight, brittle metal. In air it becomes covered with an oxide film. Reducing agent. Relative molecular weight M_r = 9,012; relative density for solid and liquid state d = 1,85; t_pl = 1287º C; t_bale = 2507º C. 1. As a result, electrolysis melt beryllium chloride formed beryllium и chlorine: 2. melt beryllium fluoride subject to electrolysis , resulting in the formation of beryllium и fluorine: 3. Oxide beryllium easily reduced by magnesium at 700 – 800º C, forming beryllium и magnesium oxide: BeO + Mg = MgO + Be 4. Beryllium fluoride is also easily reduced by magnesium at 700 – 750º C with the formation beryllium и magnesium fluoride: BeF₂ + Mg = Be + MgF₂ Qualitative reaction to beryllium – coloring the burner flame brownish-red. 1. Beryllium – strong reducing agent . That’s why he reacts with almost everyone non-metals : 1.1. Beryllium interacts with nitrogen at 700 – 900º C forming beryllium nitride: 1.2. Beryllium burns in oxygen (air) at 900º C with the formation beryllium oxide: 2Be+O₂ = 2BeO 1.3. Beryllium reacts actively at room temperature с fluorine (room temperature) , chlorine (250º C), bromine (480º C) and iodine (480º C). In this case, beryllium fluoride, beryllium chloride, beryllium bromide, beryllium iodide : Be + Br₂ = BeBr₂ 1.4. With sulfur beryllium reacts at a temperature of 1150º C to form beryllium sulfide: Be + S = BeS 1.5. With carbon Beryllium reacts at 1700 – 1900º C and vacuum, forming beryllium carbide: 2Be + C = Be₂C 2. Beryllium actively interacts with complex substances: 2.1. Beryllium reacts with boiling water . Beryllium interaction with water leads to the formation beryllium hydroxide and gas hydrogen: 2.2. Beryllium interacts with acids: 2.2.1. Beryllium reacts with dilute hydrochloric acid, this produces beryllium chloride and hydrogen: Be + 2HCl = BeCl₂ + H₂ ↑ 2.2.2. Reacting с diluted and hot nitric acid beryllium forms beryllium nitrate, nitric oxide gas and water: 2.2.3. As a result of the concentrated reaction hydrofluoric acid and beryllium precipitate is formed hydrogen tetrafluoroberyllate and gas hydrogen: 2.3. Beryllium may interact with bases: 2.3.1. Beryllium interacts with sodium hydroxide in melt at a temperature of 400 – 500º C, this forms sodium beryllate и hydrogen: Beryllium interacts with sodium hydroxide in solution , this creates sodium tetrahydroxoberyllate и hydrogen: 2.4. Beryllium reacts с gas ammonia at 500 – 700º C. As a result of this reaction, beryllium nitride и hydrogen: 2.5. Beryllium may react with oxides : As a result of the interaction of beryllium and oxide magnesium at a temperature of 1075º C is formed beryllium oxide и magnesium: Be + MgO = BeO + Mg 3. Beryllium interacts with organic matter : Beryllium may react with acetylene at 400 – 450º C, forming beryllium carbide и hydrogen:

Beryllium was discovered in 1798 by L. Vauquelin in the form of beryl earth (BeO oxide), when this French chemist was elucidating the general chemical composition of the gemstones beryl and emerald. Metallic beryllium was obtained in 1828 by F. Wöhler in Germany and, independently, by A. Bussy in France. However, due to impurities, it could not be fused. Only in 1898, the French chemist P. Lebeau, having subjected double fluoride of potassium and beryllium to electrolysis, obtained sufficiently pure metal crystals of beryllium. Interestingly, due to the sweet taste of water-soluble beryllium compounds, the element was first called “glucinium” (from the Greek glykys – sweet). Because of the similar properties of beryllium and aluminum, it was thought to be a trivalent metal with an atomic mass of 13,5. This error was corrected by D.I. Mendeleev, who, based on the pattern of changes in the properties of elements in a period, assigned beryllium a place in the second group.

Being in nature, receiving:

Beryllium is a rare element; its content in the earth’s crust is 2,6·10 -4% by mass. Sea water contains up to 6·10 -7 mg/l of beryllium. Main natural minerals containing beryllium: beryl Be₃Al₂(SiO₃)₆, phenacite Be₂SiO₄, bertrandite Be₄Si₂O₈· H₂O and helvin (Mn,Fe,Zn)₄[BeSiO₄]₃S. Transparent varieties of beryl colored with impurities of cations of other metals are precious stones, for example, green emerald, blue aquamarine, helioder, sparrow and others. Currently, they have learned to synthesize them artificially.
In the form of a simple substance in the 19th century, beryllium was obtained by the action of potassium on anhydrous beryllium chloride:
BeCl₂+2K=Be+2KCl.
Currently, beryllium is obtained by reducing its fluoride with magnesium:
BeF₂+Mg=Be+MgF₂
or by electrolysis of a melt of a mixture of beryllium and sodium chlorides. The original beryllium salts are isolated during the processing of beryllium ore.

Physical properties:

Beryllium metal is a hard, brittle, gray metal. In air, beryllium, like aluminum, is covered with an oxide film, giving it a matte color. Melting point 1278°C, boiling point about 2470°C, density 1,816 kg/m3. Stable up to 1277°C a-Be (magnesium (Mg) type hexagonal lattice, parameters a = 0,22855 nm, c = 0,35833 nm), at temperatures preceding the melting of the metal (1277-1288°C) – b-Ve with a cubic lattice.

Chemical properties:

The presence of an oxide film protects the metal from further destruction and causes its low chemical activity at room temperature. When heated, beryllium burns in air to form BeO oxide and reacts with sulfur and nitrogen. Beryllium reacts with halogens at ordinary temperatures or with low heat. All these reactions are accompanied by the release of a large amount of heat, since the strength of the crystal lattices of the resulting compounds (BeO, BeS, Be₃N₂, BeCl₂ etc.) is quite large.
Due to the formation of a strong film on the surface, beryllium does not react with water, although it is located significantly to the left of hydrogen in the series of standard potentials. Like aluminum, beryllium reacts with acids and alkali solutions:
Be + 2HCl = BeCl₂ + H₂,
Be + 2NaOH + 2H₂O=Na₂[Be(OH)₄] + H₂.
Interestingly, beryllium dissolves well in concentrated fluoride solutions:
Be + 4NH₄F+2H₂O = (NH₄)₂[BeF₄] + 2NH₃*H₂O + H₂↑
The reason is the formation of strong fluoride complexes.

The most important connections:

Beryllium oxide, BeO, occurs naturally as the rare mineral bromellite. Obtained by thermal decomposition of beryllium sulfate or hydroxide above 800° C. A high purity product is formed by the decomposition of basic acetate [Be₄O(OOCH₃)₆] above 600°C.
Uncalcined beryllium oxide is hygroscopic, adsorbs up to 34% of water, and calcined at 1500 ° C – only 0,18%. Beryllium oxide, calcined above 500°C, easily interacts with acids, more difficult – with alkali solutions, and calcined above 727°C – only with hydrofluoric acid, hot concentrated sulfuric acid and alkali melts. Resistant to molten lithium, sodium, potassium, nickel and iron.
Beryllium oxide has very high thermal conductivity. Considered one of the best refractory materials, used for making crucibles and other products
Beryllium hydroxide, Be(OH)₂ – a polymer compound insoluble in water. It exhibits amphoteric properties: Be(OH)₂ + 2KOH = K₂[Be(OH)₄], Be(OH)₂ + 2HCl = BeCl₂ + 2H₂O.
Effect on beryllium hydroxide Be(OH)₂ solutions of carboxylic acids or by evaporating solutions of their beryllium salts, beryllium oxysalts are obtained, for example, Be oxyacetate₄O(CH₃COO)₆.
Beryllium halides, colorless. christ. substances spread in the air, absorbing moisture. To obtain anhydrous chloride, the reaction 2BeO + CCl is used₄ = 2BeCl₂ + CO₂
Similar to aluminum chloride BeCl₂ is a catalyst in the Friedel–Crafts reaction. Subjects to hydrolysis in solutions
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Beryllates, in concentrated solutions and melts of alkalis there are beryllates of composition M₂Alive₂M₃Alive₄, in dilute solutions hydroxoberyllates M₂[Be(OH)₄]. Easily hydrolyze to beryllium hydroxide.
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Beryllium hydride, BeH₂ – a polymeric substance, it is obtained by the reaction: BeCl₂ + 2LiH = BeH₂ + 2LiCl
Beryllium carbide, Be₂C – is formed by the interaction of beryllium with carbon. Like aluminum carbide, it is hydrolyzed by water to form methane.

Application:

Beryllium is mainly used as an alloying additive to various alloys. The addition of beryllium significantly increases the hardness and strength of the alloys, and the corrosion resistance of the surfaces of products made from these alloys. Beryllium bronze (Cu and 3-6% Be) is a material for springs with great resistance to mechanical fatigue and absolutely no sparks during mechanical shocks.
Beryllium weakly absorbs X-rays, so the windows of X-ray tubes (through which the radiation escapes) are made from it.
In nuclear reactors, neutron reflectors are made from beryllium; it is used as a neutron moderator.
In mixtures with some a-radioactive nuclides beryllium is used in ampoule neutron sources, since during the interaction of beryllium-9 and a-particles produce neutrons: 9 Be(a,n) 12 C.
Physiological Effects: In living organisms, beryllium appears to have no biological function, but beryllium can replace magnesium in some enzymes, resulting in disruption of their function. Volatile and soluble beryllium compounds, as well as dust containing beryllium and its compounds, are very toxic and carcinogenic (MPC 0,001 mg/m 3 ). Rudakova Anna Valerievna
HF Tyumen State University, 561 group. Sources:
Beryllium // Wikipedia. Update date: 23.01.2019/97664788/04.02.2019. URL: https://ru.wikipedia.org/?oldid=XNUMX (access date: XNUMX/XNUMX/XNUMX).

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