Iron is a well-known chemical element. It belongs to metals of average chemical activity. We will look at the properties and uses of iron in this article.

Prevalence in nature

There are quite a large number of minerals that contain ferrum. First of all, it is magnetite. It is seventy-two percent iron. Its chemical formula is Fe 3 O 4. This mineral is also called magnetic iron ore. It has a light gray color, sometimes with dark gray, even black, with a metallic sheen. Its largest deposit among the CIS countries is located in the Urals.

The next mineral with a high iron content is hematite - it consists of seventy percent of this element. Its chemical formula is Fe 2 O 3. It is also called red iron ore. It has a color ranging from red-brown to red-gray. The largest deposit in the CIS countries is located in Krivoy Rog.

The third mineral containing ferrum is limonite. Here iron is sixty percent of the total mass. This is a crystalline hydrate, that is, water molecules are woven into its crystal lattice, its chemical formula is Fe 2 O 3 .H 2 O. As the name implies, this mineral has a yellow-brownish color, sometimes brown. It is one of the main components of natural ocher and is used as a pigment. It is also called brown iron ore. The largest locations are Crimea and the Urals.

Siderite, the so-called spar iron ore, contains forty-eight percent ferrum. Its chemical formula is FeCO 3. Its structure is heterogeneous and consists of crystals of different colors connected together: gray, pale green, gray-yellow, brown-yellow, etc.

The last commonly occurring mineral with high ferrum content in nature is pyrite. It has the following chemical formula: FeS 2. It contains iron forty-six percent of the total mass. Thanks to sulfur atoms, this mineral has a golden-yellow color.

Many of the minerals discussed are used to obtain pure iron. In addition, hematite is used in the manufacture of jewelry from natural stones. Pyrite inclusions may be present in lapis lazuli jewelry. In addition, iron is found in nature in living organisms - it is one of the most important components of cells. This microelement must be supplied to the human body in sufficient quantities. The healing properties of iron are largely due to the fact that this chemical element is the basis of hemoglobin. Therefore, the use of ferrum has a good effect on the condition of the blood, and therefore the entire body as a whole.

Iron: physical and chemical properties

Let's look at these two large sections in order. iron is its appearance, density, melting point, etc. That is, all the distinctive features of a substance that are associated with physics. The chemical properties of iron are its ability to react with other compounds. Let's start with the first ones.

Physical properties of iron

In its pure form under normal conditions it is a solid. It has a silver-gray color and a pronounced metallic luster. The mechanical properties of iron include a hardness level of four (medium). Iron has good electrical and thermal conductivity. The last feature can be felt by touching an iron object in a cold room. Because this material conducts heat quickly, it removes most of it from your skin in a short period of time, which is why you feel cold.

If you touch, for example, wood, you will notice that its thermal conductivity is much lower. The physical properties of iron include its melting and boiling points. The first is 1539 degrees Celsius, the second is 2860 degrees Celsius. We can conclude that the characteristic properties of iron are good ductility and fusibility. But that's not all.

Also, the physical properties of iron include its ferromagnetism. What is it? Iron, whose magnetic properties we can observe in practical examples every day, is the only metal that has such a unique distinctive feature. This is explained by the fact that this material is capable of magnetization under the influence of a magnetic field. And after the end of the action of the latter, the iron, the magnetic properties of which have just been formed, remains a magnet for a long time. This phenomenon can be explained by the fact that in the structure of this metal there are many free electrons that are able to move.

From a chemical point of view

This element belongs to the metals of medium activity. But the chemical properties of iron are typical for all other metals (except those that are to the right of hydrogen in the electrochemical series). It is capable of reacting with many classes of substances.

Let's start with simple ones

Ferrum interacts with oxygen, nitrogen, halogens (iodine, bromine, chlorine, fluorine), phosphorus, and carbon. The first thing to consider is reactions with oxygen. When ferrum is burned, its oxides are formed. Depending on the reaction conditions and the proportions between the two participants, they can be varied. As an example of this kind of interaction, the following reaction equations can be given: 2Fe + O 2 = 2FeO; 4Fe + 3O 2 = 2Fe 2 O 3; 3Fe + 2O 2 = Fe 3 O 4. And the properties of iron oxide (both physical and chemical) can be varied, depending on its type. These types of reactions occur at high temperatures.

The next thing is interaction with nitrogen. It can also only occur under the condition of heating. If we take six moles of iron and one mole of nitrogen, we get two moles of iron nitride. The reaction equation will look like this: 6Fe + N 2 = 2Fe 3 N.

When interacting with phosphorus, phosphide is formed. To carry out the reaction, the following components are needed: for three moles of ferrum - one mole of phosphorus, as a result, one mole of phosphide is formed. The equation can be written as follows: 3Fe + P = Fe 3 P.

In addition, among reactions with simple substances, interaction with sulfur can also be distinguished. In this case, sulfide can be obtained. The principle by which the process of formation of this substance occurs is similar to those described above. Namely, an addition reaction occurs. All chemical interactions of this kind require special conditions, mainly high temperatures, less often catalysts.

Reactions between iron and halogens are also common in the chemical industry. These are chlorination, bromination, iodination, fluoridation. As is clear from the names of the reactions themselves, this is the process of adding chlorine/bromine/iodine/fluorine atoms to ferrum atoms to form chloride/bromide/iodide/fluoride, respectively. These substances are widely used in various industries. In addition, ferrum is able to combine with silicon at high temperatures. Due to the varied chemical properties of iron, it is often used in the chemical industry.

Ferrum and complex substances

From simple substances we move on to those whose molecules consist of two or more different chemical elements. The first thing to mention is the reaction of ferrum with water. This is where the basic properties of iron appear. When water is heated, it forms together with iron (it is so called because when it interacts with the same water it forms a hydroxide, in other words, a base). So, if you take one mole of both components, substances such as ferrum dioxide and hydrogen are formed in the form of a gas with a pungent odor - also in one to one molar proportions. The equation for this type of reaction can be written as follows: Fe + H 2 O = FeO + H 2. Depending on the proportions in which these two components are mixed, iron di- or trioxide can be obtained. Both of these substances are very common in the chemical industry and are also used in many other industries.

With acids and salts

Since ferrum is located to the left of hydrogen in the electrochemical activity series of metals, it is capable of displacing this element from compounds. An example of this is the displacement reaction that can be observed when iron is added to an acid. For example, if you mix iron and sulfate acid (also known as sulfuric acid) of medium concentration in equal molar proportions, the result is iron (II) sulfate and hydrogen in equal molar proportions. The equation for such a reaction will look like this: Fe + H 2 SO 4 = FeSO 4 + H 2.

When interacting with salts, the reducing properties of iron appear. That is, it can be used to isolate a less active metal from salt. For example, if you take one mole and the same amount of ferrum, you can get iron (II) sulfate and pure copper in the same molar proportions.

Importance for the body

One of the most common chemical elements in the earth's crust is iron. We have already looked at it, now let’s approach it from a biological point of view. Ferrum performs very important functions both at the cellular level and at the level of the whole organism. First of all, iron is the basis of such a protein as hemoglobin. It is necessary for the transport of oxygen through the blood from the lungs to all tissues, organs, to every cell of the body, primarily to the neurons of the brain. Therefore, the beneficial properties of iron cannot be overestimated.

In addition to affecting blood formation, ferrum is also important for the full functioning of the thyroid gland (this requires not only iodine, as some believe). Iron also takes part in intracellular metabolism and regulates immunity. Ferrum is also found in particularly large quantities in liver cells, as it helps neutralize harmful substances. It is also one of the main components of many types of enzymes in our body. A person’s daily diet should contain from ten to twenty milligrams of this microelement.

Iron-rich foods

There are many of them. They are of both plant and animal origin. The first are cereals, legumes, cereals (especially buckwheat), apples, mushrooms (white), dried fruits, rose hips, pears, peaches, avocados, pumpkin, almonds, dates, tomatoes, broccoli, cabbage, blueberries, blackberries, celery, etc. The second ones are liver and meat. Consumption of foods high in iron is especially important during pregnancy, since the body of the developing fetus requires large amounts of this trace element for full growth and development.

Signs of iron deficiency in the body

Symptoms of too little ferrum entering the body are fatigue, constant freezing of hands and feet, depression, brittle hair and nails, decreased intellectual activity, digestive disorders, low performance, and thyroid dysfunction. If you notice several of these symptoms, it may be worth increasing the amount of iron-containing foods in your diet or purchasing vitamins or dietary supplements that contain ferrum. You should also consult a doctor if you feel any of these symptoms too acutely.

Use of ferrum in industry

The uses and properties of iron are closely related. Due to its ferromagnetic nature, it is used to make magnets - both weaker ones for household purposes (souvenir refrigerator magnets, etc.) and stronger ones for industrial purposes. Due to the fact that the metal in question has high strength and hardness, it has been used since ancient times for the manufacture of weapons, armor and other military and household tools. By the way, even in Ancient Egypt, meteorite iron was known, the properties of which were superior to those of ordinary metal. This special iron was also used in Ancient Rome. Elite weapons were made from it. A shield or sword made of meteorite metal could only be owned by a very rich and noble person.

In general, the metal that we are considering in this article is the most versatile among all the substances in this group. First of all, steel and cast iron are made from it, which are used to produce all kinds of products needed both in industry and in everyday life.

Cast iron is an alloy of iron and carbon, in which the latter is present from 1.7 to 4.5 percent. If the second is less than 1.7 percent, then this kind of alloy is called steel. If about 0.02 percent of carbon is present in the composition, then this is already ordinary technical iron. The presence of carbon in the alloy is necessary to give it greater strength, heat resistance, and rust resistance.

In addition, steel may contain many other chemical elements as impurities. This includes manganese, phosphorus, and silicon. Also, chromium, nickel, molybdenum, tungsten and many other chemical elements can be added to this kind of alloy to give it certain qualities. Types of steel containing a large amount of silicon (about four percent) are used as transformer steels. Those containing a lot of manganese (up to twelve to fourteen percent) are used in the manufacture of parts for railways, mills, crushers and other tools, parts of which are subject to rapid abrasion.

Molybdenum is added to the alloy to make it more heat-resistant; such steels are used as tool steels. In addition, to obtain stainless steels, which are well-known and often used in everyday life in the form of knives and other household tools, it is necessary to add chromium, nickel and titanium to the alloy. And in order to obtain impact-resistant, high-strength, ductile steel, it is enough to add vanadium to it. By adding niobium to the composition, high resistance to corrosion and chemically aggressive substances can be achieved.

The mineral magnetite, which was mentioned at the beginning of the article, is needed for the manufacture of hard drives, memory cards and other devices of this type. Due to its magnetic properties, iron can be found in transformers, motors, electronic products, etc. In addition, ferrum can be added to alloys of other metals to give them greater strength and mechanical stability. The sulfate of this element is used in gardening for pest control (along with copper sulfate).

They are indispensable for water purification. In addition, magnetite powder is used in black and white printers. The main use of pyrite is to obtain sulfuric acid from it. This process occurs in laboratory conditions in three stages. In the first stage, ferrum pyrite is burned to produce iron oxide and sulfur dioxide. At the second stage, the conversion of sulfur dioxide into its trioxide occurs with the participation of oxygen. And at the final stage, the resulting substance is passed through in the presence of catalysts, thereby producing sulfuric acid.

Getting iron

This metal is mainly mined from its two main minerals: magnetite and hematite. This is done by reducing iron from its compounds with carbon in the form of coke. This is done in blast furnaces, the temperature in which reaches two thousand degrees Celsius. In addition, there is a method for reducing ferrum with hydrogen. To do this, it is not necessary to have a blast furnace. To implement this method, they take special clay, mix it with crushed ore and treat it with hydrogen in a shaft furnace.

Conclusion

The properties and uses of iron are varied. This is perhaps the most important metal in our lives. Having become known to mankind, it took the place of bronze, which at that time was the main material for the manufacture of all tools, as well as weapons. Steel and cast iron are in many ways superior to the alloy of copper and tin in terms of their physical properties and resistance to mechanical stress.

In addition, iron is more abundant on our planet than many other metals. it is almost five percent in the earth's crust. It is the fourth most abundant chemical element in nature. Also, this chemical element is very important for the normal functioning of the body of animals and plants, primarily because hemoglobin is built on its basis. Iron is an essential trace element, the consumption of which is important for maintaining health and normal functioning of organs. In addition to the above, this is the only metal that has unique magnetic properties. It is impossible to imagine our life without ferrum.

DEFINITION

Iron- element of the eighth group of the fourth period of the Periodic Table of Chemical Elements by D. I. Mendeleev.

And the volume number is 26. The symbol is Fe (Latin “ferrum”). One of the most common metals in the earth's crust (second place after aluminum).

Physical properties of iron

Iron is a gray metal. In its pure form it is quite soft, malleable and viscous. The electronic configuration of the outer energy level is 3d 6 4s 2. In its compounds, iron exhibits oxidation states “+2” and “+3”. The melting point of iron is 1539C. Iron forms two crystalline modifications: α- and γ-iron. The first of them has a body-centered cubic lattice, the second has a face-centered cubic lattice. α-Iron is thermodynamically stable in two temperature ranges: below 912 and from 1394C to the melting point. Between 912 and 1394C γ-iron is stable.

The mechanical properties of iron depend on its purity - the content of even very small quantities of other elements in it. Solid iron has the ability to dissolve many elements in itself.

Chemical properties of iron

In humid air, iron quickly rusts, i.e. covered with a brown coating of hydrated iron oxide, which, due to its friability, does not protect iron from further oxidation. In water, iron corrodes intensely; with abundant access to oxygen, hydrate forms of iron (III) oxide are formed:

2Fe + 3/2O 2 + nH 2 O = Fe 2 O 3 ×H 2 O.

With a lack of oxygen or difficult access, mixed oxide (II, III) Fe 3 O 4 is formed:

3Fe + 4H 2 O (v) ↔ Fe 3 O 4 + 4H 2.

Iron dissolves in hydrochloric acid of any concentration:

Fe + 2HCl = FeCl 2 + H 2.

Dissolution in dilute sulfuric acid occurs similarly:

Fe + H 2 SO 4 = FeSO 4 + H 2.

In concentrated solutions of sulfuric acid, iron is oxidized to iron (III):

2Fe + 6H 2 SO 4 = Fe 2 (SO 4) 3 + 3SO 2 + 6H 2 O.

However, in sulfuric acid, the concentration of which is close to 100%, iron becomes passive and practically no interaction occurs. Iron dissolves in dilute and moderately concentrated solutions of nitric acid:

Fe + 4HNO 3 = Fe(NO 3) 3 + NO + 2H 2 O.

At high concentrations of nitric acid, dissolution slows down and iron becomes passive.

Like other metals, iron reacts with simple substances. Reactions between iron and halogens (regardless of the type of halogen) occur when heated. The interaction of iron with bromine occurs at increased vapor pressure of the latter:

2Fe + 3Cl 2 = 2FeCl 3;

3Fe + 4I 2 = Fe 3 I 8.

The interaction of iron with sulfur (powder), nitrogen and phosphorus also occurs when heated:

6Fe + N 2 = 2Fe 3 N;

2Fe + P = Fe 2 P;

3Fe + P = Fe 3 P.

Iron is capable of reacting with non-metals such as carbon and silicon:

3Fe + C = Fe 3 C;

Among the reactions of interaction of iron with complex substances, the following reactions play a special role - iron is capable of reducing metals that are in the activity series to the right of it from salt solutions (1), reducing iron (III) compounds (2):

Fe + CuSO 4 = FeSO 4 + Cu (1);

Fe + 2FeCl 3 = 3FeCl 2 (2).

Iron, at elevated pressure, reacts with a non-salt-forming oxide - CO to form substances of complex composition - carbonyls - Fe (CO) 5, Fe 2 (CO) 9 and Fe 3 (CO) 12.

Iron, in the absence of impurities, is stable in water and in dilute alkali solutions.

Getting iron

The main method of obtaining iron is from iron ore (hematite, magnetite) or electrolysis of solutions of its salts (in this case, “pure” iron is obtained, i.e. iron without impurities).

Examples of problem solving

EXAMPLE 1

Exercise

Iron scale Fe 3 O 4 weighing 10 g was first treated with 150 ml of hydrochloric acid solution (density 1.1 g/ml) with a mass fraction of hydrogen chloride of 20%, and then excess iron was added to the resulting solution. Determine the composition of the solution (in % by weight).

Solution

Let us write the reaction equations according to the conditions of the problem: 8HCl + Fe 3 O 4 = FeCl 2 + 2FeCl 3 + 4H 2 O (1); 2FeCl 3 + Fe = 3FeCl 2 (2). Knowing the density and volume of a hydrochloric acid solution, you can find its mass: m sol (HCl) = V(HCl) × ρ (HCl); m sol (HCl) = 150×1.1 = 165 g. Let's calculate the mass of hydrogen chloride: m(HCl) = m sol (HCl) ×ω(HCl)/100%; m(HCl) = 165×20%/100% = 33 g. Molar mass (mass of one mole) of hydrochloric acid, calculated using the table of chemical elements by D.I. Mendeleev – 36.5 g/mol. Let's find the amount of hydrogen chloride: v(HCl) = m(HCl)/M(HCl); v(HCl) = 33/36.5 = 0.904 mol. Molar mass (mass of one mole) of scale, calculated using the table of chemical elements by D.I. Mendeleev – 232 g/mol. Let's find the amount of scale substance: v(Fe 3 O 4) = 10/232 = 0.043 mol. According to equation 1, v(HCl): v(Fe 3 O 4) = 1:8, therefore, v(HCl) = 8 v(Fe 3 O 4) = 0.344 mol. Then, the amount of hydrogen chloride calculated by the equation (0.344 mol) will be less than that indicated in the problem statement (0.904 mol). Therefore, hydrochloric acid is in excess and another reaction will occur: Fe + 2HCl = FeCl 2 + H 2 (3). Let us determine the amount of ferric chloride substance formed as a result of the first reaction (we use indices to denote a specific reaction): v 1 (FeCl 2):v(Fe 2 O 3) = 1:1 = 0.043 mol; v 1 (FeCl 3):v(Fe 2 O 3) = 2:1; v 1 (FeCl 3) = 2 × v (Fe 2 O 3) = 0.086 mol. Let us determine the amount of hydrogen chloride that did not react in reaction 1 and the amount of iron (II) chloride formed during reaction 3: v rem (HCl) = v(HCl) – v 1 (HCl) = 0.904 – 0.344 = 0.56 mol; v 3 (FeCl 2): ​​v rem (HCl) = 1:2; v 3 (FeCl 2) = 1/2 × v rem (HCl) = 0.28 mol. Let us determine the amount of FeCl 2 substance formed during reaction 2, the total amount of FeCl 2 substance and its mass: v 2 (FeCl 3) = v 1 (FeCl 3) = 0.086 mol; v 2 (FeCl 2): ​​v 2 (FeCl 3) = 3:2; v 2 (FeCl 2) = 3/2× v 2 (FeCl 3) = 0.129 mol; v sum (FeCl 2) = v 1 (FeCl 2) + v 2 (FeCl 2) + v 3 (FeCl 2) = 0.043 + 0.129 + 0.28 = 0.452 mol; m(FeCl 2) = v sum (FeCl 2) × M(FeCl 2) = 0.452 × 127 = 57.404 g. Let us determine the amount of substance and the mass of iron that entered into reactions 2 and 3: v 2 (Fe): v 2 (FeCl 3) = 1:2; v 2 (Fe) = 1/2× v 2 (FeCl 3) = 0.043 mol; v 3 (Fe): v rem (HCl) = 1:2; v 3 (Fe) = 1/2×v rem (HCl) = 0.28 mol; v sum (Fe) = v 2 (Fe) + v 3 (Fe) = 0.043+0.28 = 0.323 mol; m(Fe) = v sum (Fe) ×M(Fe) = 0.323 ×56 = 18.088 g. Let's calculate the amount of substance and the mass of hydrogen released in reaction 3: v(H 2) = 1/2×v rem (HCl) = 0.28 mol; m(H 2) = v(H 2) ×M(H 2) = 0.28 × 2 = 0.56 g. We determine the mass of the resulting solution m’ sol and the mass fraction of FeCl 2 in it: m’ sol = m sol (HCl) + m(Fe 3 O 4) + m(Fe) – m(H 2);

The human body contains about 5 g of iron, most of it (70%) is part of blood hemoglobin.

Physical properties

In its free state, iron is a silvery-white metal with a grayish tint. Pure iron is ductile and has ferromagnetic properties. In practice, iron alloys - cast iron and steel - are usually used.

Fe is the most important and most abundant element of the nine d-metals of the Group VIII subgroup. Together with cobalt and nickel it forms the “iron family”.

When forming compounds with other elements, it often uses 2 or 3 electrons (B = II, III).

Iron, like almost all d-elements of group VIII, does not exhibit a higher valency equal to the group number. Its maximum valency reaches VI and appears extremely rarely.

The most typical compounds are those in which the Fe atoms are in oxidation states +2 and +3.

Methods for obtaining iron

1. Technical iron (alloyed with carbon and other impurities) is obtained by carbothermic reduction of its natural compounds according to the following scheme:

Recovery occurs gradually, in 3 stages:

1) 3Fe 2 O 3 + CO = 2Fe 3 O 4 + CO 2

2) Fe 3 O 4 + CO = 3FeO + CO 2

3) FeO + CO = Fe + CO 2

The cast iron resulting from this process contains more than 2% carbon. Subsequently, cast iron is used to produce steel - iron alloys containing less than 1.5% carbon.

2. Very pure iron is obtained in one of the following ways:

a) decomposition of Fe pentacarbonyl

Fe(CO) 5 = Fe + 5СО

b) reduction of pure FeO with hydrogen

FeO + H 2 = Fe + H 2 O

c) electrolysis of aqueous solutions of Fe +2 salts

FeC 2 O 4 = Fe + 2CO 2

iron(II) oxalate

Chemical properties

Fe is a metal of medium activity and exhibits general properties characteristic of metals.

A unique feature is the ability to “rust” in humid air:

In the absence of moisture with dry air, iron begins to react noticeably only at T > 150°C; upon calcination, “iron scale” Fe 3 O 4 is formed:

3Fe + 2O 2 = Fe 3 O 4

Iron does not dissolve in water in the absence of oxygen. At very high temperatures, Fe reacts with water vapor, displacing hydrogen from water molecules:

3 Fe + 4H 2 O(g) = 4H 2

The mechanism of rusting is electrochemical corrosion. The rust product is presented in a simplified form. In fact, a loose layer of a mixture of oxides and hydroxides of variable composition is formed. Unlike the Al 2 O 3 film, this layer does not protect iron from further destruction.

Types of corrosion

Protecting iron from corrosion

1. Interaction with halogens and sulfur at high temperatures.

2Fe + 3Cl 2 = 2FeCl 3

2Fe + 3F 2 = 2FeF 3

Fe + I 2 = FeI 2

Compounds are formed in which the ionic type of bond predominates.

2. Interaction with phosphorus, carbon, silicon (iron does not directly combine with N2 and H2, but dissolves them).

Fe + P = Fe x P y

Fe + C = Fe x C y

Fe + Si = Fe x Si y

Substances of variable composition are formed, such as berthollides (the covalent nature of the bond predominates in the compounds)

3. Interaction with “non-oxidizing” acids (HCl, H 2 SO 4 dil.)

Fe 0 + 2H + → Fe 2+ + H 2

Since Fe is located in the activity series to the left of hydrogen (E° Fe/Fe 2+ = -0.44 V), it is capable of displacing H 2 from ordinary acids.

Fe + 2HCl = FeCl 2 + H 2

Fe + H 2 SO 4 = FeSO 4 + H 2

4. Interaction with “oxidizing” acids (HNO 3, H 2 SO 4 conc.)

Fe 0 - 3e - → Fe 3+

Concentrated HNO 3 and H 2 SO 4 “passivate” iron, so at ordinary temperatures the metal does not dissolve in them. With strong heating, slow dissolution occurs (without releasing H 2).

In the section HNO 3 iron dissolves, goes into solution in the form of Fe 3+ cations and the acid anion is reduced to NO*:

Fe + 4HNO 3 = Fe(NO 3) 3 + NO + 2H 2 O

Very soluble in a mixture of HCl and HNO 3

5. Relation to alkalis

Fe does not dissolve in aqueous solutions of alkalis. It reacts with molten alkalis only at very high temperatures.

6. Interaction with salts of less active metals

Fe + CuSO 4 = FeSO 4 + Cu

Fe 0 + Cu 2+ = Fe 2+ + Cu 0

7. Interaction with gaseous carbon monoxide (t = 200°C, P)

Fe (powder) + 5CO (g) = Fe 0 (CO) 5 iron pentacarbonyl

Fe(III) compounds

Fe 2 O 3 - iron (III) oxide.

Red-brown powder, n. r. in H 2 O. In nature - “red iron ore”.

Methods of obtaining:

1) decomposition of iron (III) hydroxide

2Fe(OH) 3 = Fe 2 O 3 + 3H 2 O

2) pyrite firing

4FeS 2 + 11O 2 = 8SO 2 + 2Fe 2 O 3

3) nitrate decomposition

Chemical properties

Fe 2 O 3 is a basic oxide with signs of amphotericity.

I. The main properties are manifested in the ability to react with acids:

Fe 2 O 3 + 6H + = 2Fe 3+ + ZN 2 O

Fe 2 O 3 + 6HCI = 2FeCI 3 + 3H 2 O

Fe 2 O 3 + 6HNO 3 = 2Fe(NO 3) 3 + 3H 2 O

II. Weak acid properties. 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

Fe 2 O 3 + 2NaOH = 2NaFeO 2 + H 2 O

Fe 2 O 3 + MgCO 3 = Mg(FeO 2) 2 + CO 2

III. Fe 2 O 3 - feedstock for the production of iron in metallurgy:

Fe 2 O 3 + ZS = 2Fe + ZSO or Fe 2 O 3 + ZSO = 2Fe + ZSO 2

Fe(OH) 3 - iron (III) hydroxide

Methods of obtaining:

Obtained by the action of alkalis on soluble Fe 3+ salts:

FeCl 3 + 3NaOH = Fe(OH) 3 + 3NaCl

At the time of preparation, Fe(OH) 3 is a red-brown mucous-amorphous sediment.

Fe(III) hydroxide is also formed during the oxidation of Fe and Fe(OH) 2 in moist air:

4Fe + 6H 2 O + 3O 2 = 4Fe(OH) 3

4Fe(OH) 2 + 2H 2 O + O 2 = 4Fe(OH) 3

Fe(III) hydroxide is the end product of the hydrolysis of Fe 3+ salts.

Chemical properties

Fe(OH) 3 is a very weak base (much weaker than Fe(OH) 2). Shows noticeable acidic properties. Thus, Fe(OH) 3 has an amphoteric character:

1) reactions with acids occur easily:

2) fresh precipitate of Fe(OH) 3 dissolves in hot conc. solutions of KOH or NaOH with the formation of hydroxo complexes:

Fe(OH) 3 + 3KOH = 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 4 - yellow blood salt = Fe 4 3 Prussian blue (dark blue precipitate)

b) Fe 3+ + 3SCN - = Fe(SCN) 3 thiocyanate Fe(III) (blood red solution)

Iron in its pure form is obtained by various methods: electrolysis of aqueous solutions of its salts, thermal decomposition in vacuum of pentocarbonyl Zh., etc. Technically pure iron - “Armco iron”, “Vit” and other brands are produced in open-hearth furnaces. Table 2 shows the content of impurities in some. grades of iron obtained by the above methods. All these methods, with the exception of the open-hearth method, are very expensive.

The main industrial method for obtaining iron is its production in the form of various alloys with carbon—cast iron and carbon steel. When iron is reduced in blast furnaces, cast iron is formed; in mechanical engineering, steel is mainly used. Cast iron is produced by the blast furnace process.

The chemistry of the blast furnace process is as follows:

3Fe2O3 + CO = 2Fe3O4 + CO2,

Fe3O4 + CO = 3FeO + CO2,

FeO + CO = Fe + CO2.

According to their intended purpose, cast iron is divided into pig iron and cast iron. Pig iron is used for further processing into carbon and other steels. Foundry – for the production of cast iron castings. Chromium-nickel cast irons for further extraction of nickel from them or the production of low-alloyed nickel and chromium-nickel steels.

Open-hearth, converter and electric melting boil down to removing excess carbon and harmful compounds by burning them and adjusting the content of alloying elements to the specified level.

The maximum carbon content in cast iron is 4.4%, silicon 1.75%, manganese 1.75%, phosphorus 0.30%, sulfur 0.07%. In a steel melting furnace, the content of carbon, silicon and manganese must be reduced to tenths of a percent. The conversion of cast iron is carried out through oxidation reactions carried out at high temperatures. Iron, the content of which in cast iron is much higher than other substances, is partially oxidized:

2Fe + O2 = 2FeO + Q

Iron (II) oxide, mixing with the melt, oxidizes silicon, manganese, phosphorus and carbon:

Si + 2FeO = SiO2 + 2Fe + Q

Mn + FeO = MnO + Fe + Q

2P + 5FeO = P2O5 + 5Fe + Q

C + FeO = CO + Fe – Q

After the completion of oxidative reactions, the alloy contains iron (II) oxide, which must be disposed of. In addition, it is necessary to bring the content of carbon, silicon and manganese in steel to the established standards. This is achieved by adding deoxidizing agents, for example ferromanganese. Manganese reacts with iron (II) oxide:

Mn + FeO = MnO + Fe

Carbon steels are classified as: way:

basic open hearth steel

acid open hearth steel

converter steel

Elektrostal

The complexity of the metallurgical process for producing iron and steel, including the blast furnace process and the processing of cast iron, is the reason for the constant development and improvement of the method of direct production of iron from iron ores.

Synthesis of 2,2-diethoxyindanedione
Amino acids, peptides and proteins, or proteins, form a group of chemically and biologically related compounds that play a very important role in life processes. With complete hydrolysis...

Feroxide catalysts for raspberry powder, igniter composition, kramel fuel.

Method 1. Obtaining iron oxide Fe 2 O 3 from ferrous sulfate

Iron oxides are very often used as catalysts in pyrotechnic compounds. Previously, they could be purchased in stores. For example, iron oxide monohydrate FeOOH was found as the “yellow iron oxide pigment” dye. Iron oxide Fe 2 O 3 was sold in the form of red lead. Currently, it turns out that it is not easy to buy all this. I had to worry about getting it at home. I'm not much of a chemist, but life forced me. I researched recommendations online. Alas, normal, i.e. It turned out to be difficult to find a simple and safe recipe for home use. There was only one recipe that looked quite suitable, but I couldn’t find it again. I have a list of acceptable components in my head. I decided to use my own method. Oddly enough, the result turned out to be very acceptable. The result was a compound with obvious signs of iron oxide, very homogeneous and finely dispersed. Its use in raspberry powder and a secondary igniter completely confirmed that what was needed was obtained.

So, we buy it at the gardening store. iron sulfate FeSO 4, we buy pills at the pharmacy hydroperite, three packs, and stocking up in the kitchen baking soda NaHCO 3. We have all the ingredients, let's start cooking. Instead of hydroperite tablets, you can use a solution hydrogen peroxide H 2 0 2, also available in pharmacies.

In a glass container with a volume of 0.5 liters, dissolve about 80 g (a third of a pack) of iron sulfate in hot water. Add baking soda in small portions while stirring. Some kind of rubbish of a very nasty color is formed, which foams a lot.

FeSO 4 +2NaHCO 3 =FeCO 3 +Na 2 SO 4 +H 2 O+CO 2

Therefore, everything must be done in the sink. Add baking soda until foaming almost stops. After settling the mixture slightly, we begin to slowly pour in the crushed hydroperite tablets. The reaction again occurs quite rapidly with the formation of foam. The mixture acquires a characteristic color and the familiar smell of rust appears.

2FeCO 3 +H 2 O 2 =2FeOOH+2CO 2

We continue filling the hydroperite again until the foaming, that is, the reaction, almost completely stops.

We leave our chemical vessel alone and see how a red precipitate falls out - this is our oxide, more precisely the monohydrate of FeOOH oxide, or hydroxide. All that remains is to neutralize the connection. Let the sediment settle and drain off the excess liquid. Then add clean water, let it sit and drain again. We repeat this 3-4 times. Finally, dump the sediment onto a paper towel and dry. The resulting powder is an excellent catalyst and can already be used in the manufacture of stopins and secondary igniter composition, “raspberry” gunpowder and for catalyzing caramel rocket fuels. /25.01.2008, kia-soft/

However, the original recipe for “raspberry” gunpowder specifies the use of pure red oxide Fe 2 O 3. As experiments with the catalysis of caramel have shown, Fe 2 O 3 is indeed a slightly more active catalyst than FeOOH. To obtain ferric oxide, it is enough to calcinate the resulting hydroxide on a hot iron sheet, or simply in a tin can. As a result, red Fe 2 O 3 powder is formed.

After making the muffle furnace, I calcinate it for 1-1.5 hours at a temperature of 300-350°C. Very convenient. /kia-soft 06.12.2007/

P.S.
Independent research by the vega rocket scientist has shown that the catalyst obtained by this method has increased activity compared to industrial feroxides, which is especially noticeable in sugar caramel fuel obtained by evaporation.

Method 2. Obtaining iron oxide Fe 2 O 3 from ferric chloride

There is information about this possibility on the Internet, for example, on the forum of Bulgarian rocket scientists, oxide was obtained using bicarbonate, on the forum of chemists this method was mentioned, but I did not pay much attention, since I did not have ferric chloride. I was recently reminded of this option by a guest on my site RubberBigPepper. Very timely, since I was actively involved in electronics and purchased chloride. I decided to test this option for producing iron hydroxide. The method is somewhat more expensive financially, and the main component ferric chloride is more difficult to obtain, but in terms of preparation it is easier.

So we need ferric chloride FeCl 3 And baking soda NaHCO 3. Ferric chloride is commonly used for etching printed circuit boards and is sold in radio stores.

Pour two teaspoons of FeCl3 powder into a glass of hot water and stir until dissolved. Now slowly add baking soda while stirring constantly. The reaction proceeds quickly with bubbling and foaming, so there is no need to rush.

FeCl 3 +3NaHCO 3 =FeOOH+3NaCl+3CO 2 +H 2 O

Stir until the bubbling stops. We stand and get the same hydroxide FeOOH in the sediment. Next, we neutralize the compound, as in the first method, by draining the solution several times, adding water and settling. Finally, we dry the precipitate and use it as a catalyst or to obtain iron oxide Fe 2 O 3 by calcination (see method 1).

Here's a simple way. The yield is very good, from two teaspoons (~15g) of chloride you get 10g of hydroxide. The catalysts obtained by this method have been tested and are fully compliant. /kia-soft 03/11/2010/

P.S.
I cannot guarantee the 100% reliability of the chemical reaction equations, but in essence they correspond to ongoing chemical processes. The case with Fe(III) hydroxide is especially murky. According to all canons, Fe(OH) 3 should precipitate. But in the presence of peroxide (method 1) and at elevated temperatures (method 2), in theory, dehydration of the trihydroxide to FeOOH monohydrate occurs. From outward appearances, this is exactly what is happening. The resulting hydroxide powder looks like rust, and the main component of rust is FeOOH. ***