Aluminum oxide - Al2O3. Physical powers: aluminum oxide - white amorphous powder or solid white crystals. Molecular weight = 101.96, thickening - 3.97 g/cm3, melting point - 2053 °C, boiling point - 3000 °C.

Chemical power: aluminum oxide exhibits amphoteric dominance - dominance of acid oxides and basic oxides and react with acids and bases. Crystalline Al2O3 is chemically passive, amorphous is more active. Interactions with acids give middle salts of aluminum, and with bases - complex salts. hydroxoaluminate metals:

When aluminum oxide is fused with hard meadows of metals, base salts are established. metaaluminum(Anhydrous aluminum):

Aluminum oxide does not interact with water and does not differ from it.

From: aluminum oxide is rimmed with a path of inspiration for aluminum metals from their oxides: chromium, molybdenum, tungsten, vanadium and others. - metalothermy, vіdkritiy Beketova:

Zastosuvannya:оксид алюмінію застосовується для виробництва алюмінію, у вигляді порошку – для вогнетривких, хімічно стійких та абразивних матеріалів, у вигляді кристалів – для виготовлення лазерів та синтетичних дорогоцінного каміння (рубіни, сапфіри та ін.), пофарбованих домішками оксидів інших металів – Сr2О3 ( червоний колір ), Ti2O3 and Fe2O3 (black color).

Aluminum hydroxide – A1(OH)3. Physical powers: aluminum hydroxide - white amorphous (gel-like) crystalline. Maizhe is not rozchinny near the water; molecular weight - 78.00, molecular weight - 3.97 g/cm3.

Chemical power: typical amphoteric hydroxide react:

1) with acids, quenching middle salts: Al(OH)3 + 3НNO3 = Al(NO3)3 + 3Н2О;

2) with different meadows, complex salts – hydroxoaluminum: Al(OH)3 + KOH + 2H2O = K.

When Al (OH) 3 is fused from dry meadows, metaaluminates are dissolved: Al (OH) 3 + KOH = KAlO2 + 2H2O.

From:

1) from aluminum salts for a variety of meadows: AlСl3 + 3NaOH = Al(OH)3 + 3Н2О;

2) spreading aluminum nitride with water: AlN + 3H2O = Al(OH)3 + NH3?;

3) passing CO2 through the distribution of the hydroxo complex: [Al(OH)4]-+ CO2 = Al(OH)3 + HCO3-;

4) dilution on Al salt with ammonia hydrate; at room temperature, Al(OH)3 dissolves.

62. Significant characteristic of the subgroup of chromium

Elementi subgroups of chromium occupy the intermediate position of the middle transitional metals. Mayut high temperatures of melting and boiling, free time on electronic orbitals. Elementi chromiumі molybdenum Mayut a non-typical electronic structure - on the outer s-orbital, one electron can be placed (as in Nb from the subgroup VB). In these elements, there are 6 electrons on the outer d-and s-orbitals, so all the orbitals are filled by half, so there is one electron on the skin. Being similar to the electronic configuration, the element may be especially stable and resistant to oxidation. Tungsten may be more strong metal zv'azok, lower molybdenum. The degree of oxidation of the elements of the subgroup of chromium is highly variable. In lean minds, these elements show a positive oxidation level of 2 to 6, the maximum oxidation level corresponds to the group number. Not all oxidation stages are stable for elements, for chromium the most stable is +3.

All elements dissolve the MVIO3 oxide, including also oxides with lower oxidation levels. All elements and subgroups of amphoteric acid - dissolve the complex compounds of that acid.

Chrome, molybdenumі tungsten demands from metallurgy and electrical engineering. All the metals that are looked at are covered with passive oxide melting when taken on the surface or in the acid-oxidizing medium. Vidalyayuchi smelting in a chemical or mechanical way, you can increase the chemical activity of metals.

Chromium. The element is obtained from chromite ore Fe(CrO2)2, similar to coals: Fe(CrO2)2 + 4C = (Fe + 2Cr) + 4CO?.

Pure chromium is used to replace Cr2O3 for additional aluminum or electroplating, to take revenge on chromium. Seeing the chrome for additional electricity, you can take off the chrome coating, which is victorious like a decorative one.

Chromium is possessed by ferochromium, which zastosovuetsya during the bending of steel.

Molybdenum. Obtained from sulfide ore. Yogo z'єdnanny vikorivuyut under the hour of virobnitstva steel. The metal itself is possessed with the inspiration of iodine oxide. Roasting molybdenum oxide from the cold, you can remove feromolybdenum. Whiskers for the preparation of threads and tubes for winding furnaces and electrical contacts. Steel from the addition of molybdenum to vicorist is used in automobile manufacturing.

Tungsten. Obsessed with oxide, which is seen from enriched ore. Like a vicarious vicarist, aluminum or water. Tungsten, which is viishov, is ideally molded into powder at a high pressure and thermal processing (powder metallurgy). In such a vicarious look, tungsten is used for making roasting threads, adding to steel.

One of the most widely used speeches in industry is aluminum hydroxide. Have tsіy statti about new and timetsya.

What is hydroxide?

Tse khіmіchna spoluka, yak utvoryutsya when vzaimodiї oxide with water. There are three different types: acidic, basic and amphoteric. The first and the other are subdivided into groups according to their chemical activity, powers and formulas.

What is amphoteric speech?

Buty oxidite and hydroxide can be amphoteric. These are the speeches, for which it is characteristic to show both acidic and basic power, fallow in the minds of the reaction, which vicarious reagents, etc. . The rest, before speech, is most often taken from iodine hydroxide. Before amphoteric hydroxides, one can add beryllium hydroxide, saline, as well as aluminum hydroxide, which we can look at in our article.

Physical power of aluminum hydroxide

This chemistry is a solid speech. It does not separate from the water.

Aluminum hydroxide - chemical power

It was designated as a higher, valuable representative of the group of amphoteric hydroxides. Slowly that minds of the reaction, wine can show as basic, and acid power. This speech is zdatna dispersed in acids, with which strong water is established.

For example, if you mix yoga with perchloric acid in equal quantities, then take aluminum chloride with water in the same proportions. Also, one speech, with which aluminum hydroxide reacts, is sodium hydroxide. Ce typical basic hydroxide. If we analyze speech and analyze sodium hydroxide in equal quantities, then we take it under the name of sodium tetrahydroxoaluminate. In this chemical structure, there is a sodium atom, an aluminum atom, along with an oxygen atom and a hydrogen atom. However, when these speeches are fused, the reaction goes on in a different way, and it does not settle down for no reason. As a result of this process, it is possible to remove sodium metaaluminate (one atom of sodium and aluminum and two atoms of oxygen are included in this formula) with water in equal proportions, for washing, to replace the same amount of dry hydroxides of sodium and aluminum and to add high temperature to them. If you mix yoga with sodium hydroxide in other proportions, you can take sodium hexahydroxoaluminate, which can contain three atoms of sodium, one atom of aluminum and six oxygen and hydrogen. In order for speech to settle down, it is necessary to change the speech, which is seen, and the distribution of sodium hydroxide in proportions of 1: 3 is appropriate. Following the principle described above, one can take away the names of potassium tetrahydroxoaluminate and potassium hexahydroxoaluminate. It is also possible to look at the speech more slowly until it is laid out when it is poured in at a new arc of high temperatures. As a result of this kind of chemical reaction, aluminum oxide, which also can be amphoteric, and water are formed. If you take 200 g of hydroxide and heat yoga, then take 50 g of oxide and 150 g of water. The cream of its own chemical authorities, which speech also reveals is the same for all hydroxides of authority. It enters into interplay with the Cosmos with metal salts, as it may have lower chemical activity, lower aluminum. For example, you can look at the reaction between him and midi chloride, for which it is necessary to take them at a ratio of 2:3. At the same time, water-spreading aluminum chloride and sediment appear in the form of cuprum hydroxide in proportions of 2:3. Also, speech can be seen reacting with oxides of similar metals, for example, you can take the sound of midi. To carry out the reaction, aluminum hydroxide and cuprum oxide are needed at a ratio of 2: 3, after which aluminum oxide and midi hydroxide are taken away. Dominance, as described above, may also be other amphoteric hydroxides, such as saline hydroxide or beryllium.

What is sodium hydroxide?

As you can see, there are many variants of chemical reactions of aluminum hydroxide with sodium hydroxide. What is the speech? Ce is a typical basic hydroxide, so it is chemically active, a water-based base. Vіn maє all chemical dominance, which is typical for the main hydroxides.

Tobto wine can vary in acids, for example, when mixing sodium hydroxide with perchloric acid in equal quantities, you can take grub strength (sodium chloride) and water in a 1:1 ratio. Also, this hydroxide reacts with metal salts, which may have lower chemical activity, lower sodium, and both oxides. The first type has a standard exchange reaction. When added to the new, for example, sribl chloride, sodium chloride and sebyl hydroxide are dissolved, which results in a siege (the reaction of the exchange is more than once, like one of the speeches, otrimanih in її results, be a siege, gas or water). When adding sodium hydroxide, for example, zinc oxide, we take the remaining hydroxide and water. However, there are many specific reactions of this AlOH hydroxide, which have been described above.

Possession of AlOH

If we have already looked at the main chemical powers of power, we can talk about those who are used to do it. The main method of obtaining this speech is to carry out a chemical reaction between silly aluminum and sodium hydroxide (may also be vicarious and potassium hydroxide).

With such a reaction, AlOH itself is established, which falls into a greater siege, as well as a new force. For example, if you take aluminum chloride and add more potassium hydroxide to a new level, then you will be able to look at the state of the chemistry with more potassium chloride. The same method is used to extract AlOH, which transfers the chemical reaction between aluminum salt and base metal carbonate, for example, sodium. To remove aluminum hydroxide, kitchen salt and carbon dioxide in proportions of 2:6:3, it is necessary to mix aluminum chloride, sodium carbonate (soda) and water in proportions of 2:3:3.

What is aluminum hydroxide?

Aluminum hydroxide to know its status in medicine.

Zavdyaki yogo zdatnostі neutralize acid, preparations and z yogo instead of recommended for baking. Also, yoga is prescribed for virazki, gostrikh and chronic inflammatory processes of the intestines. In addition, aluminum hydroxide vicorous is used in the preparation of elastomers. Also, wines are widely used in the chemical industry for the synthesis of aluminum oxide, sodium aluminate - these processes have been explored more widely. In addition, it is often vicorous for the hour of purification of the water from the zabrudnen. Also, speech is widely used in the preparation of cosmetic products.

De zastosovuyutsya speech, how can you get for yoga help?

Aluminum oxide, which can be removed from the thermal decomposition of hydroxide, vicorizes during the preparation of ceramics, zastosovuetsya as a catalyst for carrying out various chemical reactions. Sodium tetrahydroxoaluminate to know its own way in the technology of fabrication.

2s 2p 3s 3p

Electronic configuration aluminum in wake up :

+13Al * 1s 2 2s 2 2p 6 3s 1 3p 2 1s 2s 2p 3s 3p

Aluminum showing paramagnetic power. Aluminum on the surface mineral oxide smelting, which protect the surface from a distant vzaєmodії, to resistant to corrosion.

Physical power

Aluminum- light metal with a bright white color, which can be easily molded, cast, mechanically processed. May have high heat and electrical conductivity.

Melting point 660 C, boiling point 1450 C, aluminum thickness 2.7 g/cm 3 .

Wellness in nature

Aluminum- the widest metal in nature, and the third behind the widest of the middle elements (after sourness and silicon). Zmіst in the earth's crust - close to 8%.

In nature, aluminum streaks like a spoluk:

Boxity Al 2 O 3 H 2 O(with houses SiO2, Fe 2 O 3 , CaCO 3)- aluminum oxide hydrate

Corundum Al 2 O 3 . Red corundum is called rubin, blue corundum is called sapphire.

Ways to withdraw

Aluminum I make a mimic chemical bond from sour. Therefore, the traditional methods of obtaining aluminum inspiration from oxide flow through great energy gains. For industrial for otrimannya aluminum vicorist process Hall-Eru. For lowering the melting temperature of aluminum oxide repair at melted cryolite(at a temperature of 960-970 about C) Na 3 AlF 6 and then add electrolysis with carbon electrodes. When dispersed in the melting of cryolite, aluminum oxide breaks down into ions:

Al 2 O 3 → Al 3+ + AlO 3 3-

On the cathodes vіdbuvaєtsya renovation of aluminum ions:

Before: Al 3+ +3e → Al 0

On the anode oxidized aluminat-ioniv:

A: 4AlO 3 3- - 12e → 2Al 2 O 3 + 3O 2

Sumarne rіvnyannya elektrolizu razmelt aluminum oxide:

2Al 2 O 3 → 4Al + 3O 2

Laboratory methodotrimannya aluminum polagaє in vіdnovlennі aluminum z anhydrous aluminum chloride metal potassium:

AlCl 3+3K → 4Al+3KCl

Yakіsnі reactions

Yakisna reaction to aluminum ions - interaction too muchaluminum salts from meadows . What is white amorphous siege aluminum hydroxide.

For example , aluminum chloride with sodium hydroxide:

With a distant addition to the meadow, amphoteric aluminum hydroxide differs from the adoptions tetrahydroxoaluminate:

Al(OH) 3 + NaOH = Na

Return respect , so we can use aluminum in too much meadow, then a white precipitate of aluminum hydroxide is settled, tk. at the overly meadow complex:

AlCl 3 + 4NaOH = Na

Aluminum salts can be found in addition to the water content of ammonia. With the interplay of aluminum salts with aqueous ammonia, vipadaє napіvprozoriy dreglistiy siege to aluminum hydroxide.

AlCl 3+3NH 3 H 2 O \u003d Al (OH) 3 ↓ + 3 NH 4 Cl

Al 3+ + 3NH 3 H 2 O\u003d Al (OH) 3 ↓ + 3 NH 4 +

Videodosvid you can look over the difference between aluminum chloride and ammonia

Chemical power

1. Aluminum - strong messenger . That's why I'm reacting to the bagatma non-metals .

1.1. Aluminum reacts with halogens with illumination halide:

1.2. Aluminum reaction from siroyu with illumination sulfides:

2Al + 3S → Al 2S 3

1.3. Aluminum reacth phosphorus. With whom the binary halfs are established. phosphide:

Al + P → AlP

Aluminum don't react with water .

1.4. With nitrogen aluminum reacts when heated up to 1000 pro 3 nitride:

2Al +N 2 → 2AlN

1.5. Aluminum reaction with coal with illumination aluminum carbide:

4Al + 3C → Al 4C 3

1.6. Aluminum interchange with sour with illumination oxide:

4Al + 3O 2 → 2Al 2 O 3

Videodosvid vzaєmodії aluminum s to Olivia again(Mountain aluminum on the surface) you can marvel.

2. Aluminum interchange collapsible speeches:

2.1. Chi react aluminum h water? You can easily find out on the food chain that you will dig for the troch from your memory. Without a doubt, if only once in life you would sing with aluminum saucepans or aluminum tableware. I like to put such food to students on іspitah. What is the most striking, vidpovіdі I otrimuvav vіznі - for someone aluminum still reacting with water. І more, more richly someone asked after food: “Maybe aluminum reacts with water when heated?” When heating aluminum reactants with water, already half of the respondents))

Tim is not smaller, it doesn’t matter to understand that it’s aluminum after all with water in normal minds (that and when heated) not mutually. I already wondered why: through illumination oxide melting . And clean aluminum from oxide smelting (for example, amalgamation), then wine will be interchangeable with water already active with illumination aluminum hydroxideі water:

2Al 0 + 6H 2 + O → 2Al +3 ( OH) 3 + 3H 2 0

Amalgam of aluminum can be removed by vitreating the pieces of aluminum in the range of mercury (II) chloride:

Videodosvid You can marvel at the interplay of aluminum amalgams with water.

2.2. Aluminum interact with mineral acids (with hydrochloric, phosphoric and diluted sulfuric acid) with vibe. With whom the strength of that water is established.

For example, aluminum growlingly reacts with hydrochloric acid :

2.3. For the greatest minds of aluminum don't react h concentrated sulfuric acid through passivation- Utvorennya schіlnoї oksії plіvki. When heated, the reaction goes, they settle sulfur oxide (IV), aluminum sulfateі water:

2Al + 6H 2 SO 4 (conc.) → Al 2 (SO 4) 3 + 3SO 2 + 6H 2 O

2.4. Aluminum does not react with concentrated nitric acid also through passivation.

W dilute nitric acid aluminum reacts with solutions of molecular nitrogen:

10Al + 36HNO 3 (rozb) → 3N 2 + 10Al(NO 3) 3 + 18H 2 O

When interacting with aluminum, it looks like powder already diluted with nitric acid you can hide ammonium nitrate:

8Al + 30HNO 3 (very wide) → 8Al(NO 3) 3 + 3NH 4 NO 3 + 9H 2 O

2.5. Aluminum - amphoternium metal from the meadows. When interacting with aluminum and rozchinom meadows settle down tetrahydroxoaluminateі flood:

2Al + 2NaOH + 6H 2 O → 2Na + 3H 2

Videodosvid You can marvel at the interplay of aluminum with meadow and water.

Aluminum reaction melting meadows with light aluminateі water:

2Al + 6NaOH → 2Na 3 AlO 3 + 3H 2

You can write down the reaction in a different way (in ED I recommend writing down the reaction yourself in this way):

2Al + 6NaOH → NaAlO 2 + 3H 2 + Na 2 O

2.6. Aluminum reinforcing less active metal oxides . The process of metal recovery from oxides is called aluminothermy .

For example, aluminum windows mid h midi(II) oxide. The reaction is also exothermic:

Sche butt: aluminum zalizo h free scale, sun oxide (II, III):

8Al + 3Fe 3 O 4 → 4Al 2 O 3 + 9Fe

Independence of power aluminum is also affected by the interaction of yogo with strong oxidizers: sodium peroxide, nitratesі nitrites at the puddle middle, permanganates, for chromium(VI):

2Al + 3Na 2 O 2 → 2NaAlO 2 + 2Na 2 O

8Al + 3KNO 3 + 5KOH + 18H 2 O → 8K + 3NH 3

10Al + 6KMnO 4 + 24H 2 SO 4 → 5Al 2 (SO 4) 3 + 6MnSO 4 + 3K 2 SO 4 + 24H 2 O

2Al + NaNO 2 + NaOH + 5H 2 O → 2Na + NH 3

Al + 3KMnO 4 + 4KOH → 3K 2 MnO 4 + K

4Al + K 2 Cr 2 O 7 → 2Cr + 2KAlO 2 + Al 2 O 3

Aluminium, a valuable industrial metal, which is supposed to be recycled. You can find out more about the acceptance of aluminum for processing, as well as current prices for this type of metal .

aluminum oxide

Ways to withdraw

aluminum oxidecan be removed by different methods:

1. Gorinnyam aluminum on the surface:

4Al + 3O 2 → 2Al 2 O 3

2. rozladannyam aluminum hydroxidewhen heated:

3. Aluminum oxide can be removed distribution of aluminum nitrate :

Chemical power

Aluminum oxide - typical amphoteric oxide . Interaction with acidic and basic oxides, acids, meadows.

1. When interacting with aluminum oxide basic oxides salts are settled aluminum.

For example, aluminum oxide in combination with oxide sodium:

Na 2 O + Al 2 O 3 → 2NaAlO 2

2. aluminum oxide mutual modality With whom at the melting point settle down salt—aluminum, and in different – ​​complex salts . At what aluminum oxide acid power.

For example, aluminum oxide in combination with sodium hydroxide at the melting point with illumination sodium aluminateі drive:

2NaOH + Al 2 O 3 → 2NaAlO 2 + H 2 O

aluminum oxide varies too much meadows with illumination tetrahydroxoaluminate:

Al 2 O 3 + 2NaOH + 3H 2 O → 2Na

3. Aluminum oxide is not compatible with water.

4. Aluminum oxide in combination acid oxides (Strong acids). Where do they settle salt aluminum. At what aluminum oxide main authorities.

For example, aluminum oxide in combination with sulfur oxide (VI) with illumination aluminum sulfate:

Al 2 O 3 + 3SO 3 → Al 2 (SO 4) 3

5. Aluminum oxide in combination with rozchinnymi acids with illumination middle and acid salts.

For example sulfuric acid:

Al 2 O 3 + 3H 2 SO 4 → Al 2 (SO 4) 3 + 3H 2 O

6. Aluminum oxide shows weak power oxides .

For example, aluminum oxide reacts with calcium hydride with illumination aluminum, waterі calcium oxide:

Al 2 O 3 + 3CaH 2 → 3CaO + 2Al + 3H 2

Electric strum innovating aluminum oxide (aluminum production):

2Al 2 O 3 → 4Al + 3O 2

7. Aluminum oxide is hard, non-flying. And also, wine volatile oxides (usually carbon dioxide) from salts when fused.

For example, h sodium carbonate:

Al 2 O 3 + Na 2 CO 3 → 2NaAlO 2 + CO 2

aluminum hydroxide

Ways to withdraw

1. Aluminum hydroxide is available in different sizes ammonia on the aluminum salts.

For example, aluminum chloride reacts with aqueous ammonia with illumination aluminum hydroxideі ammonium chloride:

AlCl 3 + 3NH 3 + 3H 2 O \u003d Al (OH) 3 + 3NH 4 Cl

2. skipping carbon dioxide gas, sirure gas or sіrvodnyu through the distribution of sodium tetrahydroxoaluminate:

Na + CO 2 \u003d Al (OH) 3 + NaНCO 3

In order to understand, as the reaction proceeds, you can use a clumsy trick: break up the speech of Na in a warehouse: NaOH and Al (OH) 3. Dali mi vyznaєmo, like reacting carbon dioxide gas with skin z tsikh rechovins, that is recorded products of their interaction. Because Al(OH) 3 does not react with CO 2 then we can write the right Al(OH) 3 without change.

3. Aluminum hydroxide can be possessed to the meadow on the too much aluminum salt.

For example, aluminum chloride reaction s low potassium hydroxide with illumination aluminum hydroxideі potassium chloride:

AlCl 3 + 3KOH (lack) = Al(OH) 3 ↓+ 3KCl

4. Also, aluminum hydroxide is dissolved with the interchange of retail aluminum salts with retail carbonates, sulfites and sulfides . Sulfide, carbonate and sulfite aluminum in water.

For example: aluminum bromide reaction s sodium carbonate. When aluminum hydroxide precipitates, carbon dioxide is seen and sodium bromide dissolves:

2AlBr 3 + 3Na 2 CO 3 + 3H 2 O \u003d 2Al (OH) 3 ↓ + CO 2 + 6NaBr

aluminum chloride reaction s sodium sulfide with approved aluminum hydroxide, serum water and sodium chloride:

2AlCl 3 + 3Na 2 S + 6H 2 O \u003d 2Al (OH) 3 + 3H 2 S + 6NaCl

Chemical power

1. Aluminum hydroxide reacts with rozchinnimi acids. Where do they settle medium acidic salts;

For example nitric acid with illumination aluminum nitrate:

Al(OH) 3 + 3HNO 3 → Al(NO 3) 3 + 3H 2 O

Al(OH) 3 + 3HCl → AlCl 3 + 3H 2 O

2Al(OH) 3 + 3H 2 SO 4 → Al 2 (SO 4) 3 + 6H 2 O

Al(OH) 3 + 3HBr → AlBr 3 + 3H 2 O

2. Aluminum hydroxide in combination with acid oxides of strong acids .

For example, aluminum hydroxide in combination with sulfur oxide (VI) with illumination aluminum sulfate:

2Al(OH) 3 + 3SO 3 → Al 2 (SO 4) 3 + 3H 2 O

3. Aluminum hydroxide in combination with spreading foundations (meadows).With whom at the melting point settle down salt—aluminum, and in different – ​​complex salts . At what aluminum hydroxide shows acid power.

For example, aluminum hydroxide in combination with potassium hydroxide at the melting point with illumination potassium aluminateі drive:

2KOH + Al(OH) 3 → 2KAlO 2 + 2H 2 O

aluminum hydroxide varies too much meadows with illumination tetrahydroxoaluminate:

Al(OH) 3 + KOH → K

4. G aluminum hydroxide unfolding when heated:

2Al(OH) 3 → Al 2 O 3 + 3H 2 O

Videodosvid intermodally aluminum hydroxide with hydrochloric acidі meadows(Amphoteric power of aluminum hydroxide) can be marveled at.

Aluminum salts

Aluminum nitrate and sulfate

aluminum nitrate when heated, spread out on aluminum oxide, nitric(IV) oxideі kissen:

4Al(NO 3) 3 → 2Al 2 O 3 + 12NO 2 + 3O 2

aluminum sulfate with strong heating, it expands similarly - on aluminum oxide, sulfur gasі kissen:

2Al 2 (SO 4) 3 → 2Al 2 O 3 + 6SO 2 + 3O 2

Complex salts of aluminum

To describe the powers of complex aluminum salts hydroxoaluminate, manually vikoristovuvatysya offensive method: think, break tetrahydroxoaluminate into two adjacent molecules - aluminum hydroxide and puddle metal hydroxide.

For example, sodium tetrahydroxoaluminate is broken down into aluminum hydroxide and sodium hydroxide:

Na broken into NaOH and Al(OH) 3

The dominance of the whole complex can be seen as the dominance of the whole group.

In this manner, aluminum hydroxocomplexes react with acid oxides .

For example, the hydroxocomplex collapses too much carbon dioxide gas. At the same time, NaOH reacts with dissolved acid salt (with an excess of 2), and amphoteric aluminum hydroxide does not react with carbon dioxide, then it simply falls into a siege:

Na + CO 2 → Al(OH) 3 ↓ + NaHCO 3

Similarly, potassium tetrahydroxoaluminate reacts with carbon dioxide:

K + CO 2 → Al(OH) 3 + KHCO 3

Following the same principle of tetrahydroxoaluminate reaction with clean gas SO2:

Na + SO 2 → Al(OH) 3 ↓ + NaHSO 3

K + SO 2 → Al(OH) 3 + KHSO 3

A axis pіd diєyu too strong acid the siege does not fall, because amphoteric aluminum hydroxide reacts with strong acids.

For example, h hydrochloric acid:

Na + 4HCl (over) → NaCl + AlCl 3 + 4H 2 O

Truth, for a small number of people ( non-strike ) strong acids the siege is still vipade, for the distribution of aluminum hydroxide acid is not vistachatime:

Na + HCl (marriage) → Al(OH) 3 ↓ + NaCl + H 2 O

Similar to failure nitric acid remove aluminum hydroxide:

Na + HNO 3 (nedolik) → Al(OH) 3 ↓ + NaNO 3 + H 2 O

The complex collapses with the interplay of chlorine water (aqueous solution to chlorine) Cl 2:

2Na + Cl 2 → 2Al(OH) 3 ↓ + NaCl + NaClO

With whom chlorine disproportionate.

Also, the complex can overreact aluminum chloride. In case of precipitation of aluminum hydroxide:

AlCl 3 + 3Na → 4Al(OH) 3 ↓ + 3NaCl

If you boil water from the range of complex salt and heat the speech, which is settled, then you will lose the strong aluminate:

Na → NaAlO 2 + 2H 2 O

K → KAlO 2 + 2H 2 O

Hydrolysis of aluminum salts

Rose salts of aluminum and strong acids are hydrolyzed by cation. Hydrolysis leaks step and often werewolf, then. ice ice:

Stage I: Al 3+ + H 2 O = AlOH 2+ + H +

Stage II: AlOH 2+ + H 2 O \u003d Al (OH) 2 + + H +

Stage III: Al(OH) 2 + + H 2 O = Al(OH) 3 + H +

Prote sulfide, sulfite, carbonate aluminum that ix sour salt are hydrolyzed irrevocably, more, then. water difference is not known, but spread out with water:

Al 2 (SO 4) 3 + 6NaHSO 3 → 2Al (OH) 3 + 6SO 2 + 3Na 2 SO 4

2AlBr 3 + 3Na 2 CO 3 + 3H 2 O → 2Al(OH) 3 ↓ + CO 2 + 6NaBr

2Al(NO 3) 3 + 3Na 2 CO 3 + 3H 2 O → 2Al(OH) 3 ↓ + 6NaNO 3 + 3CO 2

2AlCl 3 + 3Na 2 CO 3 + 3H 2 O → 2Al(OH) 3 ↓ + 6NaCl + 3CO 2

Al 2 (SO 4) 3 + 3K 2 CO 3 + 3H 2 O → 2Al(OH) 3 ↓ + 3CO 2 + 3K 2 SO 4

2AlCl 3 + 3Na 2 S + 6H 2 O → 2Al(OH) 3 + 3H 2 S + 6NaCl

Aluminati

Salts, in some aluminum with acidic excess (aluminum) - are dissolved in aluminum oxide at rafting from the meadows and basic oxides:

Al 2 O 3 + Na 2 O → 2NaAlO 2

To understand the power of aluminates, it is also necessary to manually break them into two borders of speech.

For example, sodium aluminate, let's think about two words: aluminum oxide and sodium oxide.

NaAlO 2 broken into Na 2 O and Al 2 O 3

Then it will become obvious to us that aluminum reacts with acids with dissolved aluminum salts :

KAlO 2 + 4HCl → KCl + AlCl 3 + 2H 2 O

NaAlO 2 + 4HCl → AlCl 3 + NaCl + 2H 2 O

NaAlO 2 + 4HNO 3 → Al(NO 3) 3 + NaNO 3 + 2H 2 O

2NaAlO 2 + 4H 2 SO 4 → Al 2 (SO 4) 3 + Na 2 SO 4 + 4H 2 O

If there is too much water, aluminate should be transferred to the salt complex:

KAlO 2 + H 2 O = K

NaAlO 2 + 2H 2 O \u003d Na

Binary sluks

aluminum sulfide under the influence of nitric acid and oxidized to sulfate:

Al 2 S 3 + 8HNO 3 → Al 2 (SO 4) 3 + 8NO 2 + 4H 2 O

or to sulfuric acid (pіd deієyu hot concentrated acid):

Al 2 S 3 + 30HNO 3 (conc. hіr.) → 2Al(NO 3) 3 + 24NO 2 + 3H 2 SO 4 + 12H 2 O

Aluminum sulfide is laid out water:

Al 2 S 3 + 6H 2 O → 2Al(OH) 3 ↓ + 3H 2 S

aluminum carbide also spreads with water when heated on aluminum hydroxide and methane:

Al 4 C 3 + 12H 2 O → 4Al (OH) 3 + 3CH 4

aluminum nitride laid out under the day mineral acids on aluminum salt and ammonium:

AlN + 4HCl → AlCl 3 + NH 4 Cl

Also, aluminum nitride is laid out under the drive:

AlN + 3H 2 O → Al(OH) 3 ↓ + NH 3

Aluminum- element 13-ї (III) of the periodic table of chemical elements with atomic number 13. It is denoted by the symbol Al. Lie down to the group of light metals. The largest expansion of metal and the third largest chemical element in the earth's crust (after acidity and silicon).

aluminum oxide Al2O3- in nature, extensions are like alumina, a white refractory powder, close to diamond in hardness.

Aluminum oxide is a natural component that can be removed from bauxite or during thermal folding of aluminum hydroxide:

2Al(OH)3 = Al2O3 + 3H2O;

Al2O3 - amphoteric oxide, chemically inert, the core of its own mineral crystal solution. Wines do not differ in water, do not interact with acids and acids, and may react only with melted meadows.

Close to 1000°C intensively interact with meadows and carbonates of puddle metals with approved aluminates:

Al2O3 + 2KOH = 2KAlO2 + H2O; Al2O3 + Na2CO3 = 2NaAlO2 + CO2.

Other forms of Al2O3 are more active;

Amphoteric dominance of aluminum oxide is revealed by the interaction with acidic and basic oxides with solutions of salts:

Al2O3 + 3SO3 = Al2(SO4)3 (basic power), Al2O3 + Na2O = 2NaAlO2 (acid power).

Aluminum hydroxide, Al(OH)3- z'ednannya aluminum oxide from water. There was a draggy speech, a filthy rozchinna near the water, there is an amphoteric power. Take away at the interaction of aluminum salts with aquatic meadows: AlCl3 + 3NaOH \u003d Al (OH) 3 + 3NaCl

Aluminum hydroxide is a typical amphoteric compound;

2Al(OH)3 + 6HCl = 2AlCl3 + 6H2O. Al(OH)3 + NaOH + 2H2O = Na.

When heated, the process of dehydration is laid down, and it can be schematically presented in the following order:

Al(OH)3 = AlOOH + H2O. 2AlOOH = Al2O3 + H2O.

Aluminati salt, which is utvoryayutsya when dividing meadows on fresh precipitation aluminum hydroxide: Al (OH) 3 + NaOH \u003d Na (tetrahydroxoaluminate sodium)

Alumina is also taken away when there is a difference in metal aluminum (or Al2O3) in meadows: 2Al + 2NaOH + 6Н2О = 2Na + ЗН2

Hydroxoaluminum dissolve when Al (OH) 3 interacts with too much meadow: Al (OH) 3 + NaOH (izb) \u003d Na

Salts of aluminum. With aluminum hydroxide it is possible to remove all aluminum salts. May all the salts of aluminium be kindly dispersed by the water; aluminum phosphate is badly separated from water.
Alumina salts exhibit an acid reaction. The butt can be reversed with water to aluminum chloride:
AlCl3 + 3H2O "Al (OH) 3 + 3HCl
It is more practical to wash a lot of aluminum salt. So, for example, anhydrous aluminum chloride AlCl3 vicorates in chemical practice as a catalyst in the processing of naphtha
Aluminum sulfate Al2(SO4)3 18H2O is used as a coagulant for purification of tap water, as well as for the production of paper.
Widely vykorivuyutsya underwine salts of aluminum - galun KAl (SO4) 2 12H2O, NaAl (SO4) 2 12H2O, NH4Al (SO4) 2 12H2O and in.

Zastosuvannya- Zavdyaki complex of powers wide extensions in thermal possession. - Alyumіnіy and yogo alloys save mіtsnіst at low temperatures. Zavdyaki tsyom vin widely vikoristovuєtsya in cryogenic technology. - aluminum - ideal material for making mirrors. - In the production of everyday materials, it is like a gas-forming agent. rozrobtsі stony aluminum as especially mitsnogo and light material.

Yak vіdnovnik- Yak component termіtu, sumіshey for alumothermії- In pyrotechnics. - Aluminum zastosovuyt for the replacement of rare metals from their oxides or halides. (Aluminothermy)

Aluminothermy.- a method of containing metals, non-metals (as well as alloys) inspired by their metal oxides and aluminum.

Aluminum oxide Al 2 O 3 (alumina) - the most important part of aluminum. In a clean look - there was an arc of refractory speech, there are few modifications, from some of the most crystallized - Al 2 O 3 and amorphous in - Al 2 O 3. In nature, it looks like different rocks and minerals.

Three important powers of Al 2 O 3 are as follows:

1) the speech is hard (only a diamond and some half-boron can be delivered);

2) amorphous Al 2 O 3 has a high surface activity and water-absorbing power - an effective adsorbent;

3) high catalytic activity, especially widely vicorous in organic synthesis;

4) vikoristovuetsya as a wear catalyst - nickel, platinum and other.

For chemical powers Al 2 O 3 is a typical amphoteric oxide.

The water does not differ and does not interact with it.

I. Occurs in acids and meadows:

1) Al 2 O 3 + 6HCl = 2AlCl 3 + ZN 2 O

Al 2 O 3 + 6Н + = 2Al 3+ + ЗН 2 O

2) Al 2 O 3 + 2NaOH + ZN 2 O \u003d 2Na

Al 2 O 3 + 20H - + ZH 2 O \u003d 2 [Al (OH) 4] -

II. Alloys with solid meadows and metal oxides, facilitating anhydrous metaaluminum:

A 2 O 3 + 2KOH \u003d 2KAlO 2 + H 2 O

A 2 O 3 + MgO \u003d Mg (AlO) 2

Methods of keeping Al 2 O 3

1. Study of natural bauxites.

2. Burning Al powder in a streak of sour.

3. Thermal expansion of Al(OH) 3 .

4. Thermal distribution of active salts.

4Al(NO 3) 3 \u003d 2Al 2 O 3 + 12NO 2 + 3O 2

5. Aluminothermy, for example: Fe 2 O 3 + 2Al = Al 2 O 3 + 2Fe

Aluminum hydroxide Al(OH) 3 is a hard, barrelless speech, non-staining in water. When heated, it expands:

2Al(OH) 3 \u003d Al 2 O 3 + ZN 2 O

The removal of cym by the Al 2 O 3 method is called aluminogel.

Behind the chemical dominance is a typical amphoteric hydroxide, which varies both in acids and in meadows:

Al(OH) 3 + 3HCl \u003d AlCl 3 + ZH 2 R

Al(OH) 3 + NaOH = Na sodium tetrahydroxoaluminate

When Al (OH) 3 is fused with solid meadows, metaaluminates are dissolved - salts of metahydroxide AlO (OH), which can be seen as salts of metaaluminum acid HAlO 2:

Al (OH) 3 + NaOH \u003d NaAlO 2 + 2H 2 O

Aluminum salts

Due to the amphotericity of aluminum hydroxide and the possibility of using yoga in ortho- and metaform, there are different types of salts. Since Al(OH) 3 exhibits even weakly acidic and even weakly basic power, all types of salts in water varieties are strongly hydrolyzed, as a result of which insoluble Al(OH)3 settles into the terminal bag. The presence of aluminum salts in an aqueous variety of other types of salts is determined by the pH value of this variety.

1. Salts of Al 3+ with anions of strong acids (AlCl 3 , Al 2 (SO 4) 3 , Al(NO 3) 3 , AlBr 3) are used in acidification. In the neutral medium of metaaluminum, which should be replaced by aluminum in the warehouse of the AlO 2 anion, it should be in a solid steel. Widen in nature. When separated near water, they are converted to hydroxoaluminum.

2. Hydroxoaluminum, which can be used to remove aluminum from anion warehouses, is used in puddles. In a neutral medium, they are strongly hydrolyzed.

3. Metaaluminum to replace aluminum in storage for AlO 2 anion. Іsnuyut at a firm stand. Widen in nature. When separated near water, they are converted to hydroxoaluminum.

Mutual conversion of aluminum salts is described by the scheme:

Methods of sedimentation (obtainment) of Al (OH) 3 from iodine salts

I. Settlement of rozchinіv, scho vengeance of Al 3+ salts:

Al 3+ + ZONE - \u003d Al (OH) 3 ↓

a) to give strong meadows, dodanih without too much

AlCl 3 + 3NaOH \u003d Al (OH) 3 ↓ + ZN 2 O

b) diya water distributions of ammonia (weak base)

AlCl 3 + 3NH 3 + ZN 2 O \u003d Al (OH) 3 ↓ + 3NH 4 Cl

c) diya salts of even weak acids, the occurrence of such hydrolysis causes a puddle of the middle (too much BIN -)

2AlCl 3 + 3Na 2 CO 3 + 3H 2 O \u003d Al (OH) 3 ↓ + ZSO 2 + 6NaCl

Al 2 (SO 4) 3 + 3K 2 S + 6H 2 O \u003d 2Al (OH) 3 ↓ + 3K 2 SO 4 + 3H 2 S

II. Settlement of the reasons why hydroxoaluminum should be avenged:

[Al(OH) 4] - + H + = Al(OH) 3 ↓+ H 2 O

a) diyu strong acids, added without excess

Na [Al (OH) 4] + HCl \u003d Al (OH) 3 ↓ + NaCl + H 2 O

2[Al (OH) 4] + H 2 SO 4 \u003d 2Al (OH) 3 ↓ + Na 2 SO 4 + 2H 2 O

b) diya weak acids, for example, passing CO 2

Na [Al (OH) 4] + CO 2 \u003d Al (OH) 3 ↓ + NaHCO 3

III. Precipitation as a result of reverse or non-reversible hydrolysis of Al 3+ salts

a) reverse hydrolysis

Al 3+ + H 2 O \u003d Al (OH) 2+ + H +

Al 3+ + 2H 2 O \u003d Al (OH) 2 + + 2H +

Al 3+ + 3H 2 O \u003d Al (OH) 3 + + 3H +

b) irreversible hydrolysis

Al 2 S 3 + 6H 2 O \u003d 2Al (OH) 3 ↓ + 3H 2 S