68. Iron compounds
Iron (II) oxide FeO– a black crystalline substance, insoluble in water and alkalis. FeO matches the base Fe(OH)2.
Receipt. Iron (II) oxide can be obtained by incomplete reduction of magnetic iron ore with carbon (II) oxide:
Chemical properties. It is the main oxide. Reacting with acids, it forms salts:
Iron (II) hydroxide Fe(OH)2- white crystalline substance.
Receipt. Iron (II) hydroxide is obtained from divalent iron salts under the action of alkali solutions:
Chemical properties. Basic hydroxide. Reacts with acids:
In air, Fe(OH)2 is oxidized to Fe(OH)3:
Iron(III) oxide Fe2O3– a brown substance, found in nature in the form of red iron ore, insoluble in water.
Receipt. When firing pyrite:
Chemical properties. Exhibits weak amphoteric properties. When interacting with alkalis, it forms salts:
Iron (III) hydroxide Fe(OH)3– a red-brown substance, insoluble in water and excess alkali.
Receipt. Obtained by the oxidation of iron (III) oxide and iron (II) hydroxide.
Chemical properties. It is an amphoteric compound (with a predominance of basic properties). Precipitates under the action of alkalis on ferric iron salts:
Ferrous salts obtained by reacting metallic iron with appropriate acids. They are highly hydrolyzed, which is why their aqueous solutions are energetic reducing agents:
When heated above 480 °C, it decomposes, forming oxides:
When alkalis act on iron (II) sulfate, iron (II) hydroxide is formed:
Forms crystalline hydrate - FeSO4?7Н2О (iron sulfate). Iron (III) chloride FeCl3 – dark brown crystalline substance.
Chemical properties. Let's dissolve in water. FeCl3 exhibits oxidizing properties.
Reducing agents - magnesium, zinc, hydrogen sulfide, oxidize without heating.
Chemical properties
Chemical properties
Fe(II) salts
Chemical properties
Chemical properties
FeO - Fe(II) oxide.
Refractory black pyrophoric powder, insoluble in water.
In terms of chemical properties, FeO is a basic oxide. Reacts with acids to form salts:
FeO + 2HCl = FeCl 2 + H 2 O
4FeO + O 2 = 2Fe 2 O 3
3FeO + 10HNO 3 = 3Fe(NO 3) 3 + NO + 5H 2 O
Fe(OH) 2 – Fe(II) hydroxide– a white solid, insoluble in water.
In terms of chemical properties, it is a weak base, easily reacts with acids and does not react with alkalis. Fe(OH) 2 is an unstable substance: when heated without access to air, it decomposes, and in air it spontaneously oxidizes:
Fe(OH) 2 = FeO + H 2 O (t)
4Fe(OH) 2 + O 2 + 2H 2 O = 4Fe(OH) 3
pale green brown
The most practically important are: FeSO 4, FeCl 2, Fe(NO 3) 3, FeS, FeS 2.
The formation of complex and double salts with alkali metal and ammonium salts is characteristic:
Fe(CN) 2 + 4KCN = K 4 (yellow blood salt)
FeCl 2 + 2KCl = K 2
Mora's Salt
(NH 4) 2 SO 4 FeSO 4 6H 2 O
inkstone
The hydrated Fe 2+ ion is pale green in color.
1. Soluble Fe 2+ salts in aqueous solutions undergo hydrolysis with the formation of an acidic environment:
Fe 2+ + H 2 O ↔ FeOH + + H +
2. Exhibit general properties of typical salts (ion-exchange interactions):
FeS + 2HCl = FeCl 2 + H 2 S
FeCl 2 + 2NaOH = Fe(OH) 2 ↓ + 2NaCl
FeSO 4 + BaCl 2 = FeCl 2 + BaSO 4 ↓
3. Easily oxidized by strong oxidizing agents
Fe 2+ - 1ē → Fe 3+
10Fe +2 SO 4 + 2KMnO 4 + 8H 2 SO 4 = 5Fe +3 (SO 4) 3 + K 2 SO 4 + 2MnSO 4 + 8H 2 O
4. Qualitative reactions for the detection of Fe 2+ cations:
a) 3Fe 2+ + 2 3- = Fe 3 2 ↓
red blood salt turnbull's blue
(dark blue precipitate)
b) under the influence of alkali, a pale green precipitate of Fe(OH) 2 precipitates, which gradually turns green in air and then turns into brown Fe(OH) 3.
Fe(III) compounds
Fe 2 O 3 - iron (III) oxide
Red-brown powder, insoluble in water. In nature - “red iron ore”.
Fe 2 O 3 is a basic oxide with signs of amphotericity.
1. The main properties are manifested in the ability to react with acids:
Fe 2 O 3 + 6HCl = 2FeCl 3 + 3H 2 O
Fe 2 O 3 + 6HNO 3 = 2Fe(NO 3) 3 + 3H 2 O
2. Fe 2 O 3 does not dissolve in aqueous solutions of alkalis, but when fused with solid oxides, alkalis and carbonates, ferrites form:
Fe 2 O 3 + CaO = Ca(FeO 2) 2 (t)
Fe 2 O 3 + 2NaOH = 2NaFeO 2 + H 2 O (t)
Fe 2 O 3 + MgCO 3 = Mg(FeO 2) 2 + CO 2 (t)
3. Fe 2 O 3 – feedstock for the production of iron in metallurgy:
Fe 2 O 3 + 3C = 2Fe + 3CO or Fe 2 O 3 + 3CO = 2Fe + 3CO 2
Fe(OH) 3 – iron (III) hydroxide
Fe(OH) 3 is a very weak base (much weaker than Fe(OH) 2). Fe(OH) 3 is amphoteric in nature:
1) Reactions with acids occur easily:
Fe(OH) 3 + 3HCl = FeCl 3 + 3H 2 O
2) Fresh precipitate Fe(OH) 3 dissolves in hot concentrated solutions of KOH or NaOH to form hydroxo complexes:
Fe(OH) 3 + 2KOH = K 3
In an alkaline solution, Fe(OH) 3 can be oxidized to ferrates (salts of iron acid H 2 FeO 4 not released in the free state):
2Fe(OH) 3 + 10KOH + 3Br 2 = 2K 2 FeO 4 + 6KBr + 8H 2 O
Fe 3+ salts
The most practically important are:
Fe 2 (SO 4) 3, FeCl 3, Fe(NO 3) 3, Fe(SCN) 3, K 3
The formation of double salts - iron alum is characteristic:
(NH 4)Fe(SO 4) 2 12H 2 O
KFe(SO 4) 2 12H 2 O
Fe 3+ salts are often colored both in the solid state and in aqueous solution. This is due to the presence of hydrated forms or hydrolysis products.
Iron oxides are compounds of iron and oxygen.
The most famous are three iron oxides: iron oxide (II) - FeO, iron (III) oxide – Fe 2 O 3 and iron (II, III) oxide – Fe 3 O 4.
Iron(II) oxide
The chemical formula of ferrous oxide is FeO . This connection is black in color.
FeO Reacts easily with dilute hydrochloric acid and concentrated nitric acid.
FeO + 2HCl → FeCl 2 + H 2 O
FeO + 4HNO 3 → Fe(NO 3) 3 + NO 2 + 2H 2 O
It does not react with water or salts.
When interacting with hydrogen at a temperature of 350 o C and coke at a temperature above 1000 o C, it is reduced to pure iron.
FeO +H 2 → Fe + H 2 O
FeO +C → Fe + CO
Iron (II) oxide is obtained in different ways:
1. As a result of the reduction reaction of ferric oxide with carbon monoxide.
Fe 2 O 3 + CO → 2 FeO + CO 2
2. Heating iron with low oxygen pressure
2Fe + O 2 → 2 FeO
3. Decomposing ferrous oxalate in vacuum
FeC 2 O 4 → FeO +CO + CO 2
4. Interaction of iron with iron oxides at a temperature of 900-1000 o
Fe + Fe 2 O 3 → 3 FeO
Fe + Fe 3 O 4 → 4 FeO
In nature, ferrous oxide exists as the mineral wustite.
In industry it is used in the smelting of cast iron in blast furnaces, in the process of blackening (bluing) of steel. It is found in dyes and ceramics.
Iron(III) oxide
Chemical formula Fe2O3 . This is a compound of ferric iron with oxygen. It is a red-brown powder. Hematite is found in nature as a mineral.
Fe2O3 has other names: iron oxide, red lead, crocus, pigment red 101, food coloringE172 .
Does not react with water. Can interact with both acids and alkalis.
Fe 2 O 3 + 6HCl → 2 FeCl 3 + 3H 2 O
Fe 2 O 3 + 2NaOH → 2NaFeO 2 + H 2 O
Iron (III) oxide is used for painting building materials: brick, cement, ceramics, concrete, paving slabs, linoleum. It is added as a dye to paints and enamels, and to printing inks. Iron oxide is used as a catalyst in the production of ammonia. In the food industry it is known as E172.
Iron (II, III) oxide
Chemical formula Fe3O4 . This formula can be written in another way: FeO Fe 2 O 3.
It is found in nature as the mineral magnetite, or magnetic iron ore. It is a good conductor of electric current and has magnetic properties. Formed when iron burns and when superheated steam acts on iron.
3Fe + 2 O 2 → Fe 3 O 4
3Fe + 4H 2 O → Fe 3 O 4 + 4H 2
Heating at a temperature of 1538 o C leads to its disintegration
2Fe 3 O 4 → 6FeO + O 2
Reacts with acids
Fe 3 O 4 + 8HCl → FeCl 2 + 2FeCl 3 + 4H 2 O
Fe 3 O 4 + 10HNO 3 → 3Fe(NO 3) 3 + NO 2 + 5H 2 O
Reacts with alkalis upon fusion
Fe 3 O 4 + 14NaOH → Na 3 FeO 3 + 2Na 5 FeO 4 + 7H 2 O
Reacts with oxygen in the air
4 Fe 3 O 4 + O 2 → 6Fe 2 O 3
Reduction occurs by reaction with hydrogen and carbon monoxide
Fe 3 O 4 + 4H 2 → 3Fe + 4H 2 O
Fe 3 O 4 + 4CO → 3Fe +4CO 2
Magnetic nanoparticles of Fe 3 O 4 oxide have found application in magnetic resonance imaging. They are also used in the production of magnetic media. Iron oxide Fe 3 O 4 is included in paints that are produced specifically for warships, submarines and other equipment. Electrodes are made from fused magnetite for some electrochemical processes.
Iron(II) oxide
TU 6-09-1404-76
Fe2O3
Iron(III) oxide- a complex inorganic substance, a compound of iron and oxygen with the chemical formula Fe 2 O 3.
Iron(III) oxide is an amphoteric oxide with a high predominance of basic properties. Red-brown color. Thermally resistant to high temperatures. Formed when iron burns in air. Does not react with water. Reacts slowly with acids and alkalis. Reduced by carbon monoxide, molten iron. It fuses with oxides of other metals and forms double oxides - spinels.
Hematite is found in nature as a widespread mineral, the impurities of which cause the reddish color of laterite, red soils, and also the surface of Mars; another crystalline modification occurs as the mineral maghemite.
Iron oxide Fe 2 O 3 is crystals from red-brown to black-violet. The chemical is thermally stable. No reaction with water. Slow reaction with alkalis and acids.
Iron oxide Fe 2 O 3 is used as a raw material for the production of cast iron in the blast furnace process. This chemical is a catalyst in the ammonia manufacturing process. It is included in ceramics as one of the components; it is used in the manufacture of mineral paints and colored cements. Iron oxide Fe2O3 is effective for thermal welding of steel structural elements. This substance is associated with recording sound and images on magnetic media. Fe2O3 is a quality polishing agent for polishing steel and glass parts.
It is the main component of red lead. Fe 2 O 3 in the food industry is a fairly common food additive E172.
|
Physical properties |
|
|---|---|
|
State |
hard |
|
Molar mass |
159.69 g/mol |
|
Density |
5.242 g/cm³ |
|
Thermal properties |
|
|
T. float. |
1566 °C |
|
T. kip. |
1987 °C |
|
Steam pressure |
0 ± 1 mmHg |
Fe 2 O 3 is used in the smelting of cast iron in the blast furnace process, a catalyst in the production of ammonia, a component of ceramics, colored cements and mineral paints, in thermite welding of steel structures, as a carrier of analog and digital information (for example, sound and image) on magnetic tapes (ferrimagnetic γ -Fe 2 O 3), as a polishing agent (red crocus) for steel and glass.
In the food industry it is used as a food coloring (E172).
In rocket modeling it is used to produce catalyzed caramel fuel, which has a burning rate 80% higher than conventional fuel.
It is the main component of red lead (kolkotar).
In the petrochemical industry it is used as a main component of a dehydrogenation catalyst in the synthesis of diene monomers.
FeO(l): 251 kJ/mol
Iron(II) oxide (ferrous oxide) - a complex inorganic compound of divalent iron and oxygen.
Physical properties
The connection is black. Crystal lattice like rock salt. It has a non-stoichiometric structure with a homogeneity range from Fe 0.84 O to Fe 0.95 O. This is due to the fact that its crystal lattice is stable only when not all of its nodes are occupied by iron atoms. Iron (II) oxide becomes stable only with increasing temperature.
Being in nature
Iron(II) oxide occurs naturally as the mineral wustite.
Receipt
- Heating iron at low oxygen partial pressure:
- Decomposition of iron (II) oxalate in vacuum:
- Interaction of iron with iron (III) oxide or iron (II,III) oxide:
- Reduction of iron(III) oxide by carbon monoxide:
- Thermal decomposition of iron (II,III) oxide:
- Thermal decomposition of iron (II) hydroxide without air access:
- Thermal decomposition of iron (II) carbonate without air access:
Chemical properties
- Interaction with dilute hydrochloric acid:
- Reaction with concentrated nitric acid:
- Fusion with sodium hydroxide:
- Interaction with oxygen:
- Interaction with hydrogen sulfide:
- Reduction with hydrogen and coke:
Application
- Participates in the blast furnace process of iron smelting.
- It is used as a component of ceramics and mineral paints.
- In the food industry it is widely used as a food coloring under the number E172.
The formation of a durable, thin layer of iron(II) oxide on the surface of steel is the result of a process called bluing. By adjusting the thickness of this layer, in addition to black, you can achieve any tarnish color. The technology for producing color patterns on steel is based on this property of iron(II) oxide.
Toxicity
Aerosols (dust, smoke) of iron (II) oxide with prolonged exposure are deposited in the lungs and cause siderosis, a type of pneumoconiosis with a relatively benign course.
see also
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Literature
- Lidin R. A. “Handbook for schoolchildren. Chemistry" M.: Asterel, 2003.
- Volkov A.I., Zharsky I.M. Large chemical reference book / A.I. Volkov, I.M. Zharsky. - Mn.: Modern School, 2005. - 608 p.
- Lidin R.A. and others. Chemical properties of inorganic substances: Textbook. manual for universities. 3rd ed., revised/R.A. Lidin, V.A. Molochko, L.L. Andreeva; Ed. R.A.Lidina. - M.: Chemistry, 200. 480 pp.: ill.
- Greenwood N. Chemistry of elements: in 2 volumes.
- .Greenwood, A.Earnshaw; lane from English - M.: BINOM. Knowledge Laboratory, 2011. - (Best foreign textbook)
- Harmful chemicals. Inorganic compounds of groups V-VIII: Reference. ed./ A.L. Bandman, N.V. Volkova, T.D. Grekhova, etc.; Ed. V.A. Filova and others - L.: Chemistry, 1989. 592 p.
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Excerpt characterizing Iron(II) Oxide
Natasha blushed crimson hearing these words.- How she blushes, how she blushes, ma delicieuse! [my precious!] - said Helen. - Definitely come. Si vous aimez quelqu"un, ma delicieuse, ce n"est pas une raison pour se cloitrer. Si meme vous etes promise, je suis sure que votre promis aurait desire que vous alliez dans le monde en son absence plutot que de deperir d'ennui. [Just because you love someone, my lovely, you should not live like a nun. Even if you are a bride, I am sure that your groom would prefer that you go out into society in his absence than die of boredom.]
“So she knows that I’m a bride, so she and her husband, with Pierre, with this fair Pierre,” thought Natasha, talked and laughed about it. So it’s nothing.” And again, under the influence of Helen, what had previously seemed terrible seemed simple and natural. “And she is such a grande dame, [important lady,] so sweet and obviously loves me with all her heart,” Natasha thought. And why not have fun? thought Natasha, looking at Helen with surprised, wide-open eyes.
Marya Dmitrievna returned to dinner, silent and serious, obviously defeated by the old prince. She was still too excited from the collision to be able to calmly tell the story. To the count's question, she answered that everything was fine and that she would tell him tomorrow. Having learned about Countess Bezukhova’s visit and invitation to the evening, Marya Dmitrievna said:
“I don’t like hanging out with Bezukhova and wouldn’t recommend it; Well, if you promised, go, you’ll be distracted,” she added, turning to Natasha.
Count Ilya Andreich took his girls to Countess Bezukhova. There were quite a lot of people at the evening. But the whole society was almost unfamiliar to Natasha. Count Ilya Andreich noted with displeasure that this entire society consisted mainly of men and women, known for their freedom of treatment. M lle Georges, surrounded by young people, stood in the corner of the living room. There were several Frenchmen, and among them Metivier, who had been her housemate since Helene's arrival. Count Ilya Andreich decided not to play cards, not to leave his daughters, and to leave as soon as the Georges performance was over.
Anatole was obviously at the door waiting for the Rostovs to enter. He immediately greeted the count, approached Natasha and followed her. As soon as Natasha saw him, just like in the theater, a feeling of vain pleasure that he liked her and fear from the absence of moral barriers between her and him overwhelmed her. Helen joyfully received Natasha and loudly admired her beauty and dress. Soon after their arrival, M lle Georges left the room to get dressed. In the living room they began to arrange chairs and sit down. Anatole pulled out a chair for Natasha and wanted to sit next to her, but the count, who had not taken his eyes off Natasha, sat down next to her. Anatole sat in the back.
M lle Georges, with bare, dimpled, thick arms, wearing a red shawl worn over one shoulder, walked out into the empty space left for her between the chairs and stopped in an unnatural pose. An enthusiastic whisper was heard. M lle Georges looked sternly and gloomily at the audience and began to speak some poems in French, which dealt with her criminal love for her son. In some places she raised her voice, in others she whispered, raising her head solemnly, in others she stopped and wheezed, rolling her eyes.
- Adorable, divin, delicieux! [Delightful, divine, wonderful!] - was heard from all sides. Natasha looked at fat Georges, but did not hear anything, did not see and did not understand anything of what was happening in front of her; she only felt again completely irrevocably in that strange, crazy world, so far from the previous one, in that world in which it was impossible to know what was good, what was bad, what was reasonable and what was crazy. Anatole was sitting behind her, and she, feeling his closeness, fearfully waited for something.
After the first monologue, the whole company stood up and surrounded m lle Georges, expressing their delight to her.
- How good she is! - Natasha said to her father, who, along with others, stood up and moved through the crowd towards the actress.
“I don’t find it, looking at you,” said Anatole, following Natasha. He said this at a time when she alone could hear him. “You are lovely... from the moment I saw you, I haven’t stopped....”
“Come on, let’s go, Natasha,” said the count, returning for his daughter. - How good!
Natasha, without saying anything, walked up to her father and looked at him with questioning, surprised eyes.
After several receptions of recitation, M lle Georges left and Countess Bezukhaya asked for company in the hall.
The Count wanted to leave, but Helen begged him not to ruin her impromptu ball. The Rostovs remained. Anatole invited Natasha to a waltz and during the waltz he, shaking her waist and hand, told her that she was ravissante [charming] and that he loved her. During the eco-session, which she again danced with Kuragin, when they were left alone, Anatole did not say anything to her and only looked at her. Natasha was in doubt whether she had seen what he said to her during the waltz in a dream. At the end of the first figure he shook her hand again. Natasha raised her frightened eyes to him, but there was such a self-confidently tender expression in his affectionate gaze and smile that she could not look at him and say what she had to say to him. She lowered her eyes.
“Don’t tell me such things, I’m engaged and love someone else,” she said quickly... “She looked at him. Anatole was not embarrassed or upset by what she said.
- Don't tell me about this. What do I care? - he said. “I’m saying that I’m madly, madly in love with you.” Is it my fault that you are amazing? Let's start.
Natasha, animated and anxious, looked around her with wide, frightened eyes and seemed more cheerful than usual. She remembered almost nothing of what happened that evening. They danced the Ecossaise and Gros Vater, her father invited her to leave, she asked to stay. Wherever she was, no matter who she spoke to, she felt his gaze on her. Then she remembered that she asked her father for permission to go to the dressing room to straighten her dress, that Helen followed her, told her laughing about her brother’s love, and that in the small sofa room she again met Anatole, that Helen disappeared somewhere, they were left alone and Anatole, Taking her hand, he said in a gentle voice:
- I can’t go to you, but will I really never see you? I love you madly. Really never?...” and he, blocking her path, brought his face closer to hers.
His brilliant, large, masculine eyes were so close to her eyes that she saw nothing but these eyes.
- Natalie?! – his voice whispered questioningly, and someone painfully squeezed her hands.
- Natalie?!
“I don’t understand anything, I have nothing to say,” said her look.
Hot lips pressed against hers and at that very moment she felt free again, and the noise of Helen’s steps and dress was heard in the room. Natasha looked back at Helen, then, red and trembling, looked at him with frightened questioning and went to the door.
“Un mot, un seul, au nom de Dieu, [One word, only one, for God’s sake,” said Anatole.
She stopped. She really needed him to say this word, which would explain to her what had happened and to which she would answer him.
“Nathalie, un mot, un seul,” he kept repeating, apparently not knowing what to say, and he repeated it until Helen approached them.
Helen and Natasha went out into the living room again. Without staying for dinner, the Rostovs left.
Returning home, Natasha did not sleep all night: she was tormented by the insoluble question of who she loved, Anatole or Prince Andrei. She loved Prince Andrei - she remembered clearly how much she loved him. But she loved Anatole too, that was certain. “Otherwise, how could all this have happened?” she thought. “If after that, when I said goodbye to him, I could answer his smile with a smile, if I could allow this to happen, then it means that I fell in love with him from the first minute. This means that he is kind, noble and beautiful, and it was impossible not to love him. What should I do when I love him and love another? she told herself, not finding answers to these terrible questions.