All possible obtaining oxides. Methods for obtaining oxides

1. Oxidation of simple substances with oxygen (combustion of simple substances):

2Mg + O 2 \u003d 2MgO

4P + 5O 2 \u003d 2P 2 O 5.

The method is not applicable for the production of alkali metal oxides, since when oxidized, alkali metals usually give not oxides, but peroxides (Na 2 O 2 , K 2 O 2).

Noble metals are not oxidized by atmospheric oxygen, for example, Au, Ag, Pt.

2. Oxidation of complex substances (salts of certain acids and hydrogen compounds of non-metals):

2ZnS + 3O 2 = 2ZnO + 2SO 2

2H 2 S + 3O 2 \u003d 2SO 2 + 2H 2 O

3.Decomposition upon heating of hydroxides (bases and oxygen-containing acids):

Cu (OH) 2 CuO + H 2 O

H 2 SO 3 SO 2 + H 2 O

This method cannot be used to obtain oxides of alkali metals, since the decomposition of alkalis occurs at too high temperatures.

4.Decomposition of some salts of oxygen-containing acids:

CaCO 3 CaO + CO 2

2Рb (NO 3) 2 2РbО + 4NO 2 + O 2

It should be borne in mind that alkali metal salts do not decompose when heated to form oxides.

1.1.7. Applications of oxides.

A number of natural minerals are oxides (see Table 7) and are used as ore raw materials to obtain the corresponding metals.

For example:

Bauxite A1 2 O 3 nH 2 O.

Hematite Fe 2 O 3 .

Magnetite FeO · Fe 2 O 3 .

Cassiterite SnO 2 .

Pyrolusite МnO 2 .

Rutile TiO 2 .

mineral corundum (A1 2 O 3) having great hardness, is used as an abrasive material. Its transparent, red and blue colored crystals are precious stones - ruby and sapphire.

Quicklime (CaO) obtained by roasting limestone (CaCO 3), is widely used in construction, agriculture and as a reagent for drilling fluids.

iron oxides (Fe 2 O 3, Fe 3 O 4) used in drilling oil and gas wells as weighting agents and hydrogen sulfide neutralizing agents.

Silicon(IV) oxide (SiO2) in the form of quartz sand, it is widely used for the production of glass, cement and enamels, for sandblasting the surface of metals, for hydrosandblasting perforation and hydraulic fracturing in oil and gas wells. In the form of the smallest spherical particles (aerosol), it is used as an effective defoamer for drilling fluids and as a filler in the production of rubber products (white rubber).

A number of oxides (A1 2 O 3, Cr 2 O 3, V 2 O 5, CuO, NO) are used as catalysts in modern chemical industries.

Being one of the main combustion products of coal, oil and oil products, carbon dioxide (CO 2 ), when injected into productive formations, enhances their oil recovery. CO 2 is also used to fill fire extinguishers and carbonate drinks.

The oxides formed during the violation of the combustion regimes of fuel (NO, CO) or during the combustion of sulfurous fuel (SO 2) are products that pollute the atmosphere. Modern production, as well as transport, provides for strict control over the content of such oxides and their neutralization,

Oxides of nitrogen (NO, NO 2) and sulfur (SO 2 , SO 3) are intermediate products in large-scale production of nitric (HNO 3) and sulfuric (H 2 SO 4) acids.

Oxides of chromium (Cr 2 O 3) and lead (2РbО · РbО 2 - minium) are used for the production of anticorrosive paint compositions.

Questions for self-control on the topic of oxides

1. What main classes are all inorganic compounds divided into?

2. What are oxides?

3. What types of oxides do you know?

4. What oxides are non-salt-forming (indifferent)?

5. Give definitions: a) basic oxide, b) acid oxide,

c) amphoteric oxide.

6. What elements form basic oxides?

7. What elements form acid oxides?

8. Write the formulas of some amphoteric oxides.

9. How are the names of oxides oxides formed?

10. Name the following oxides: Cu 2 O, FeO, Al 2 O 3, Mn 2 O 7, SO 2.

11. Draw the formulas of the following oxides graphically: a) sodium oxide, b) calcium oxide, c) aluminum oxide, d) sulfur oxide (1V), e) manganese oxide (VII). State their nature.

12. Write the formulas for the higher oxides of the elements of periods II and III. Name them. How does the chemical character of oxides of periods II and III change?

13. What are the chemical properties of a) basic oxides, b) acid oxides, d) amphoteric oxides?

14. What oxides react with water? Give examples.

15. Prove the amphoteric properties of the following oxides: a) beryllium oxide, b) zinc oxide, c) tin (IV) oxide.

16. What methods of obtaining oxides do you know?

17. Write the reaction equations for obtaining the following oxides by all methods known to you: a) zinc oxide, b) copper (II) oxide, c) silicon oxide (1V).

18. Name some of the applications of oxides.

1.2. Foundations

Bases are chemical substances that decompose (dissociate) in an aqueous solution (or in a melt) into positively charged metal ions and negatively charged hydroxyl ions. (Arrhenius definition):

sodium hydroxide sodium cation hydroxide ion

Bases are complex substances formed during the hydration of basic oxides.

For example:

Na 2 O + H 2 O \u003d NaOH- sodium hydroxide

BaO + H 2 O \u003d Ba (OH) 2– barium hydroxide

Oxides are inorganic compounds consisting of two chemical elements, one of which is oxygen in the -2 oxidation state. the only the non-oxidizing element is fluorine, which combines with oxygen to form oxygen fluoride. This is because fluorine is a more electronegative element than oxygen.

This class of compounds is very common. Every day a person encounters a variety of oxides in everyday life. Water, sand, the carbon dioxide we exhale, car exhaust, rust are all examples of oxides.

Classification of oxides

All oxides, according to their ability to form salts, can be divided into two groups:

Salt-forming oxides (CO 2, N 2 O 5, Na 2 O, SO 3, etc.)
Non-salt-forming oxides (CO, N 2 O, SiO, NO, etc.)

In turn, salt-forming oxides are divided into 3 groups:

Basic oxides- (Metal oxides - Na 2 O, CaO, CuO, etc.)
Acid oxides- (Non-metal oxides, as well as metal oxides in the oxidation state V-VII - Mn 2 O 7, CO 2, N 2 O 5, SO 2, SO 3, etc.)
(Metal oxides with oxidation state III-IV as well as ZnO, BeO, SnO, PbO)

This classification is based on the manifestation of certain chemical properties by oxides. So, basic oxides correspond to bases, and acidic oxides correspond to acids. Acid oxides react with basic oxides to form the corresponding salt, as if the base and acid corresponding to these oxides had reacted: Likewise, amphoteric oxides correspond to amphoteric bases, which can exhibit both acidic and basic properties: Chemical elements exhibiting different oxidation states can form various oxides. In order to somehow distinguish between the oxides of such elements, after the name of the oxides, valency is indicated in brackets.

CO 2 - carbon monoxide (IV)

N 2 O 3 - nitric oxide (III)

Physical properties of oxides

Oxides are very diverse in their physical properties. They can be both liquids (H 2 O), and gases (CO 2, SO 3) or solids (Al 2 O 3, Fe 2 O 3). At the same time, basic oxides are, as a rule, solid substances. Oxides also have the most diverse color - from colorless (H 2 O, CO) and white (ZnO, TiO 2) to green (Cr 2 O 3) and even black (CuO).

Basic oxides

Some oxides react with water to form the corresponding hydroxides (bases): Basic oxides react with acidic oxides to form salts: They react similarly with acids, but with the release of water: Oxides of metals less active than aluminum can be reduced to metals:

Acid oxides

Acid oxides react with water to form acids: Some oxides (for example, silicon oxide SiO2) do not react with water, so acids are produced in other ways.

Acid oxides react with basic oxides to form salts: In the same way, with the formation of salts, acid oxides react with bases: If a given oxide corresponds to a polybasic acid, then an acid salt can also form: Non-volatile acid oxides can replace volatile oxides in salts:

As mentioned earlier, amphoteric oxides, depending on the conditions, can exhibit both acidic and basic properties. So they act as basic oxides in reactions with acids or acid oxides, with the formation of salts: And in reactions with bases or basic oxides, they exhibit acidic properties:

Obtaining oxides

Oxides can be obtained in a variety of ways, we will give the main ones.

Most oxides can be obtained by direct interaction of oxygen with a chemical element: When firing or burning various binary compounds: Thermal decomposition of salts, acids and bases: Interaction of some metals with water:

Application of oxides

Oxides are extremely common throughout the globe and are used both in everyday life and in industry. The most important oxide, hydrogen oxide, water, made life possible on Earth. Sulfur oxide SO 3 is used to produce sulfuric acid, as well as for food processing - this increases the shelf life, for example, of fruits.

Iron oxides are used to produce paints, the production of electrodes, although most iron oxides are reduced to metallic iron in metallurgy.

Calcium oxide, also known as quicklime, is used in construction. Oxides of zinc and titanium are white and insoluble in water, therefore they have become a good material for the production of paints - white.

Silicon oxide SiO 2 is the main component of glass. Chromium oxide Cr 2 O 3 is used for the production of colored green glasses and ceramics, and due to its high strength properties, for polishing products (in the form of GOI paste).

Carbon monoxide CO 2 , which all living organisms emit during respiration, is used for fire extinguishing, and also, in the form of dry ice, for cooling something.

The substances that form the basis of our physical world are composed of different types of chemical elements. Four of them are the most common. These are hydrogen, carbon, nitrogen and oxygen. The last element can bind with particles of metals or non-metals and form binary compounds - oxides. In our article, we will study the most important methods for obtaining oxides in the laboratory and industry. We also consider their basic physical and chemical properties.

State of aggregation

Oxides, or oxides, exist in three states: gaseous, liquid and solid. For example, the first group includes such well-known and widespread compounds in nature as carbon dioxide - CO 2, carbon monoxide - CO, sulfur dioxide - SO 2 and others. In the liquid phase, there are such oxides as water - H 2 O, sulfuric anhydride - SO 3, nitric oxide - N 2 O 3. Obtaining oxides, named by us, can be carried out in the laboratory, however, such of them, as well as sulfur trioxide, are also mined in industry. This is due to the use of these compounds in the technological cycles of iron smelting and sulfate acid production. Carbon monoxide is used to reduce iron from ore, and sulfuric anhydride is dissolved in sulfate acid and oleum is mined.

Classification of oxides

There are several types of oxygen-containing substances, consisting of two elements. The chemical properties and methods for obtaining oxides will depend on which of the listed groups the substance belongs to. carbon is obtained by direct combination of carbon with oxygen, carrying out a hard oxidation reaction. Carbon dioxide can also be isolated in the process of exchange and strong inorganic acids:

HCl + Na 2 CO 3 \u003d 2NaCl + H 2 O + CO 2

What reaction is the hallmark of acid oxides? This is their interaction with alkalis:

SO 2 + 2NaOH → Na 2 SO 3 + H 2 O

Amphoteric and non-salt-forming oxides

Indifferent oxides, such as CO or N 2 O, are not capable of reactions leading to the appearance of salts. On the other hand, most acidic oxides can react with water to form acids. However, this is not possible for silicon oxide. It is advisable to obtain silicate acid indirectly: from silicates that react with strong acids. Amphoteric will be such binary compounds with oxygen that are capable of reactions with both alkalis and acids. We include the following compounds in this group - these are the known oxides of aluminum and zinc.

Production of sulfur oxides

In its compounds with oxygen, sulfur exhibits different valencies. So, in sulfur dioxide, the formula of which is SO 2, it is tetravalent. In the laboratory, sulfur dioxide is produced in the reaction between sulfate acid and sodium hydrosulfite, the equation of which is

NaHSO 3 + H 2 SO 4 → NaHSO 4 + SO 2 + H 2 O

Another way to extract SO 2 is a redox process between copper and high concentration sulfate acid. The third laboratory method for obtaining sulfur oxides is the combustion under the hood of a sample of a simple sulfur substance:

Cu + 2H 2 SO 4 \u003d CuSO 4 + SO 2 + 2H 2 O

In industry, sulfur dioxide can be obtained by burning sulfur-containing minerals zinc or lead, as well as by burning pyrite FeS 2. The sulfur dioxide obtained by this method is used for the extraction of sulfur trioxide SO 3 and further - sulfate acid. Sulfur dioxide with other substances behaves like an oxide with acidic features. For example, its interaction with water leads to the formation of sulfite acid H 2 SO 3:

SO 2 + H 2 O \u003d H 2 SO 3

This reaction is reversible. The degree of acid dissociation is low, so the compound is classified as a weak electrolyte, and sulfurous acid itself can exist only in an aqueous solution. Sulfur dioxide molecules are always present in it, which give the substance a pungent odor. The reacting mixture is in a state of equal concentration of reactants and products, which can be shifted by changing the conditions. So, when alkali is added to a solution, the reaction will proceed from left to right. In the case of removing sulfur dioxide from the reaction sphere by heating or blowing through a mixture of gaseous nitrogen, the dynamic equilibrium will shift to the left.

Sulfuric anhydride

We continue to consider the properties and methods for obtaining sulfur oxides. If sulfur dioxide is burned, the result is an oxide in which sulfur has an oxidation state of +6. It's sulfur trioxide. The compound is in the liquid phase, quickly hardens in the form of crystals at temperatures below 16 °C. A crystalline substance can be represented by several allotropic modifications that differ in the structure of the crystal lattice and melting points. Sulfuric anhydride exhibits the properties of a reducing agent. Interacting with water, it forms an aerosol of sulfate acid, therefore, in industry, H 2 SO 4 is mined by dissolving sulfuric anhydride in concentrated oleum. As a result, oleum is formed. By adding water to it, a solution of sulfuric acid is obtained.

Basic oxides

Having studied the properties and production of sulfur oxides belonging to the group of acidic binary compounds with oxygen, we will consider oxygen compounds of metal elements.

Basic oxides can be determined by such a feature as the presence in the composition of the molecules of metal particles of the main subgroups of the first or second groups of the periodic system. They are classified as alkaline or alkaline earth. For example, sodium oxide - Na 2 O can react with water, resulting in the formation of chemically aggressive hydroxides - alkalis. However, the main chemical property of basic oxides is the interaction with organic or inorganic acids. It goes with the formation of salt and water. If hydrochloric acid is added to white powdered copper oxide, we will find a bluish-green solution of copper chloride:

CuO + 2HCl \u003d CuCl 2 + H 2 O

Heating solid insoluble hydroxides is another important way to obtain basic oxides:

Ca(OH) 2 → CaO + H 2 O

Conditions: 520-580°C.

In our article, we examined the most important properties of binary compounds with oxygen, as well as methods for obtaining oxides in the laboratory and industry.

Oxides.

These are complex substances consisting of TWO elements, one of which is oxygen. For example:

CuO– copper(II) oxide

AI 2 O 3 - aluminum oxide

SO 3 - sulfur oxide (VI)

Oxides are divided (they are classified) into 4 groups:

Na 2 O– Sodium oxide

CaO - calcium oxide

Fe 2 O 3 - iron oxide (III)

2). Acidic- These are oxides non-metals. And sometimes metals if the oxidation state of the metal> 4. For example:

CO 2 - Carbon monoxide (IV)

P 2 O 5 - Phosphorus oxide (V)

SO 3 - Sulfur oxide (VI)

3). Amphoteric- These are oxides that have the properties of both basic and acidic oxides. You need to know the five most common amphoteric oxides:

BeO-beryllium oxide

ZnO– Zinc Oxide

AI 2 O 3 - Aluminum oxide

Cr 2 O 3 - Chromium (III) oxide

Fe 2 O 3 - Iron oxide (III)

4). Non-salt-forming (indifferent)- These are oxides that do not exhibit the properties of either basic or acidic oxides. There are three oxides to remember:

CO - carbon monoxide (II) carbon monoxide

NO– nitric oxide (II)

N 2 O– nitric oxide (I) laughing gas, nitrous oxide

Methods for obtaining oxides.

one). Combustion, i.e. interaction with oxygen of a simple substance:

4Na + O 2 \u003d 2Na 2 O

4P + 5O 2 \u003d 2P 2 O 5

2). Combustion, i.e. interaction with oxygen of a complex substance (consisting of two elements) in this case, two oxides.

2ZnS + 3O 2 = 2ZnO + 2SO 2

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

3). Decomposition three weak acids. Others do not decompose. In this case, acid oxide and water are formed.

H 2 CO 3 \u003d H 2 O + CO 2

H 2 SO 3 \u003d H 2 O + SO 2

H 2 SiO 3 \u003d H 2 O + SiO 2

4). Decomposition insoluble grounds. Basic oxide and water are formed.

Mg(OH) 2 \u003d MgO + H 2 O

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

5). Decomposition insoluble salts. A basic oxide and an acidic oxide are formed.

CaCO 3 \u003d CaO + CO 2

MgSO 3 \u003d MgO + SO 2

Chemical properties.

I. basic oxides.

alkali.

Na 2 O + H 2 O \u003d 2NaOH

CaO + H 2 O \u003d Ca (OH) 2

СuO + H 2 O = the reaction does not proceed, because a possible base containing copper is insoluble

2). Reacts with acids to form salt and water. (Basic oxide and acids ALWAYS react)

K 2 O + 2HCI \u003d 2KCl + H 2 O

CaO + 2HNO 3 \u003d Ca (NO 3) 2 + H 2 O

3). Reaction with acidic oxides to form a salt.

Li 2 O + CO 2 \u003d Li 2 CO 3

3MgO + P 2 O 5 \u003d Mg 3 (PO 4) 2

4). Hydrogen reacts to form metal and water.

CuO + H 2 \u003d Cu + H 2 O

Fe 2 O 3 + 3H 2 \u003d 2Fe + 3H 2 O

II.Acid oxides.

one). Interaction with water, this should form acid.(OnlySiO 2 does not interact with water)

CO 2 + H 2 O \u003d H 2 CO 3

P 2 O 5 + 3H 2 O \u003d 2H 3 PO 4

2). Interaction with soluble bases (alkalis). This produces salt and water.

SO 3 + 2KOH \u003d K 2 SO 4 + H 2 O

N 2 O 5 + 2KOH \u003d 2KNO 3 + H 2 O

3). Interaction with basic oxides. In this case, only salt is formed.

N 2 O 5 + K 2 O \u003d 2KNO 3

Al 2 O 3 + 3SO 3 \u003d Al 2 (SO 4) 3

Basic exercises.

one). Complete the reaction equation. Determine its type.

K 2 O + P 2 O 5 \u003d

Decision.

To write down what is formed as a result - it is necessary to determine - which substances reacted - here it is potassium oxide (basic) and phosphorus oxide (acidic) according to the properties - the result should be SALT (see property No. 3) and the salt consists of atoms metals (in our case, potassium) and an acid residue which includes phosphorus (i.e. PO 4 -3 - phosphate) Therefore

3K 2 O + P 2 O 5 \u003d 2K 3 RO 4

type of reaction - compound (since two substances react, and one is formed)

2). Carry out transformations (chain).

Ca → CaO → Ca(OH) 2 → CaCO 3 → CaO

Decision

To complete this exercise, you must remember that each arrow is one equation (one chemical reaction). We number each arrow. Therefore, it is necessary to write down 4 equations. The substance written to the left of the arrow (the starting substance) enters into the reaction, and the substance written to the right is formed as a result of the reaction (the reaction product). Let's decipher the first part of the record:

Ca + ... .. → CaO We pay attention that a simple substance reacts, and an oxide is formed. Knowing the methods for obtaining oxides (No. 1), we come to the conclusion that in this reaction it is necessary to add -oxygen (O 2)

2Са + О 2 → 2СаО

Let's move on to transformation number 2

CaO → Ca(OH) 2

CaO + ... ... → Ca (OH) 2

We come to the conclusion that here it is necessary to apply the property of basic oxides - interaction with water, because only in this case a base is formed from the oxide.

CaO + H 2 O → Ca (OH) 2

Let's move on to transformation number 3

Ca (OH) 2 → CaCO 3

Сa(OH) 2 + ….. = CaCO 3 + …….

We come to the conclusion that here we are talking about carbon dioxide CO 2 since. only it, when interacting with alkalis, forms a salt (see property No. 2 of acid oxides)

Ca (OH) 2 + CO 2 \u003d CaCO 3 + H 2 O

Let's move on to transformation number 4

CaCO 3 → CaO

CaCO 3 \u003d ... .. CaO + ......

We come to the conclusion that more CO 2 is formed here, because. CaCO 3 is an insoluble salt, and it is during the decomposition of such substances that oxides are formed.

CaCO 3 \u003d CaO + CO 2

3). Which of the following substances interacts with CO 2 . Write reaction equations.

BUT). hydrochloric acid b. Sodium hydroxide B). Potassium oxide d. Water

D). Hydrogen E). Sulfur oxide (IV).

We determine that CO 2 is an acid oxide. And acidic oxides react with water, alkalis and basic oxides ... Therefore, from the list above, we select answers B, C, D And it is with them that we write down the reaction equations:

one). CO 2 + 2NaOH \u003d Na 2 CO 3 + H 2 O

2). CO 2 + K 2 O \u003d K 2 CO 3

Today we begin our acquaintance with the most important classes of inorganic compounds. Inorganic substances are divided by composition, as you already know, into simple and complex.

OXIDE

ACID

BASE

SALT

E x O y

HnA

A - acid residue

Me(OH)b

OH - hydroxyl group

Me n A b

Complex inorganic substances are divided into four classes: oxides, acids, bases, salts. We start with the oxide class.

OXIDES

oxides - these are complex substances consisting of two chemical elements, one of which is oxygen, with a valence equal to 2. Only one chemical element - fluorine, combining with oxygen, forms not an oxide, but oxygen fluoride OF 2.
They are called simply - "oxide + element name" (see table). If the valence of a chemical element is variable, then it is indicated by a Roman numeral enclosed in parentheses after the name of the chemical element.

Formula	Name	Formula	Name
	carbon monoxide (II)	Fe2O3	iron(III) oxide
	nitric oxide (II)	CrO3	chromium(VI) oxide
Al2O3	aluminium oxide		zinc oxide
N 2 O 5	nitric oxide (V)	Mn2O7	manganese(VII) oxide

Classification of oxides

All oxides can be divided into two groups: salt-forming (basic, acidic, amphoteric) and non-salt-forming or indifferent.

metal oxides Me x O y

Non-metal oxides neMe x O y

Main

Acidic

Amphoteric

Acidic

Indifferent

I, II

V-VII

ZnO, BeO, Al 2 O 3,

Fe 2 O 3 , Cr 2 O 3

> II

neMe

I, II

neMe

CO, NO, N 2 O

1). Basic oxides are oxides that correspond to bases. The main oxides are oxides metals 1 and 2 groups, as well as metals side subgroups with valency I and II (except ZnO - zinc oxide and BeO – beryllium oxide):

2). Acid oxides are oxides to which acids correspond. Acid oxides are non-metal oxides (except for non-salt-forming - indifferent), as well as metal oxides side subgroups with valence from V before VII (For example, CrO 3 is chromium (VI) oxide, Mn 2 O 7 is manganese (VII) oxide):

3). Amphoteric oxides are oxides, which correspond to bases and acids. These include metal oxides main and secondary subgroups with valency III , sometimes IV , as well as zinc and beryllium (For example, BeO, ZnO, Al 2 O 3, Cr 2 O 3).

4). Non-salt-forming oxides are oxides that are indifferent to acids and bases. These include non-metal oxides with valency I and II (For example, N 2 O, NO, CO).

Conclusion: the nature of the properties of oxides primarily depends on the valency of the element.

For example, chromium oxides:

CrO(II- main);

Cr 2 O 3 (III- amphoteric);

CrO 3 (VII- acid).

Classification of oxides

(by solubility in water)

Acid oxides

Basic oxides

Amphoteric oxides

Soluble in water.

Exception - SiO 2

(not soluble in water)

Only oxides of alkali and alkaline earth metals dissolve in water.

(these are metals

I "A" and II "A" groups,

exception Be , Mg )

They do not interact with water.

Insoluble in water

Complete the tasks:

1. Write out separately the chemical formulas of salt-forming acidic and basic oxides.

NaOH, AlCl 3 , K 2 O, H 2 SO 4 , SO 3 , P 2 O 5 , HNO 3 , CaO, CO.

2. Substances are given : CaO, NaOH, CO 2 , H 2 SO 3 , CaCl 2 , FeCl 3 , Zn(OH) 2 , N 2 O 5 , Al 2 O 3 , Ca(OH) 2 , CO 2 , N 2 O, FeO, SO 3 , Na 2 SO 4 , ZnO, CaCO 3 , Mn 2 O 7 , CuO, KOH, CO, Fe(OH) 3

Write down the oxides and classify them.

Obtaining oxides

Simulator "Interaction of oxygen with simple substances"

1. Combustion of substances (Oxidation by oxygen)	a) simple substances Training apparatus	2Mg + O 2 \u003d 2MgO
1. Combustion of substances (Oxidation by oxygen)	b) complex substances	2H 2 S + 3O 2 \u003d 2H 2 O + 2SO 2
2. Decomposition of complex substances (use table of acids, see appendices)	a) salt SALTt= BASIC OXIDE + ACID OXIDE	CaCO 3 \u003d CaO + CO 2
	b) Insoluble bases Me(OH)bt= Me x O y+ H 2 O	Cu (OH) 2 t \u003d CuO + H 2 O
	c) oxygen-containing acids HnA=ACID OXIDE + H 2 O	H 2 SO 3 \u003d H 2 O + SO 2

Physical properties of oxides

At room temperature, most oxides are solids (CaO, Fe 2 O 3, etc.), some are liquids (H 2 O, Cl 2 O 7, etc.) and gases (NO, SO 2, etc.).

Chemical properties of oxides

CHEMICAL PROPERTIES OF BASIC OXIDES

1. Basic oxide + Acid oxide \u003d Salt (r. compounds)

CaO + SO 2 \u003d CaSO 3

2. Basic oxide + Acid \u003d Salt + H 2 O (r. exchange)

3 K 2 O + 2 H 3 PO 4 = 2 K 3 PO 4 + 3 H 2 O

3. Basic oxide + Water \u003d Alkali (r. compounds)

Na 2 O + H 2 O \u003d 2 NaOH

CHEMICAL PROPERTIES OF ACID OXIDES

1. Acid oxide + Water \u003d Acid (p. Compounds)

With O 2 + H 2 O \u003d H 2 CO 3, SiO 2 - does not react

2. Acid oxide + Base \u003d Salt + H 2 O (r. exchange)

P 2 O 5 + 6 KOH \u003d 2 K 3 PO 4 + 3 H 2 O

3. Basic oxide + Acid oxide \u003d Salt (p. Compound)

CaO + SO 2 \u003d CaSO 3

4. Less volatiles displace more volatiles from their salts

CaCO 3 + SiO 2 \u003d CaSiO 3 + CO 2

CHEMICAL PROPERTIES OF AMPHOTERIC OXIDES

They interact with both acids and alkalis.

ZnO + 2 HCl = ZnCl 2 + H 2 O

ZnO + 2 NaOH + H 2 O \u003d Na 2 [Zn (OH) 4] (in solution)

ZnO + 2 NaOH = Na 2 ZnO 2 + H 2 O (when fused)

Application of oxides

Some oxides do not dissolve in water, but many react with water to combine:

SO 3 + H 2 O \u003d H 2 SO 4

CaO + H 2 O = Ca( Oh) 2

The result is often very desirable and useful compounds. For example, H 2 SO 4 is sulfuric acid, Ca (OH) 2 is slaked lime, etc.

If oxides are insoluble in water, then people skillfully use this property as well. For example, zinc oxide ZnO is a white substance, therefore it is used to prepare white oil paint (zinc white). Since ZnO is practically insoluble in water, any surface can be painted with zinc white, including those that are exposed to atmospheric precipitation. Insolubility and non-toxicity make it possible to use this oxide in the manufacture of cosmetic creams and powders. Pharmacists make it an astringent and drying powder for external use.

Titanium oxide (IV) - TiO 2 has the same valuable properties. It also has a beautiful white color and is used to make titanium white. TiO 2 is insoluble not only in water, but also in acids; therefore, coatings made of this oxide are particularly stable. This oxide is added to plastic to give it a white color. It is part of the enamels for metal and ceramic utensils.

Chromium oxide (III) - Cr 2 O 3 - very strong crystals of dark green color, insoluble in water. Cr 2 O 3 is used as a pigment (paint) in the manufacture of decorative green glass and ceramics. The well-known GOI paste (short for the name “State Optical Institute”) is used for grinding and polishing optics, metal products in jewelry.

Due to the insolubility and strength of chromium (III) oxide, it is also used in printing inks (for example, for coloring banknotes). In general, oxides of many metals are used as pigments for a wide variety of paints, although this is by no means their only application.

Tasks for fixing

1. Write out separately the chemical formulas of salt-forming acidic and basic oxides.

NaOH, AlCl 3 , K 2 O, H 2 SO 4 , SO 3 , P 2 O 5 , HNO 3 , CaO, CO.

Select from the list: basic oxides, acidic oxides, indifferent oxides, amphoteric oxides and give them names.

3. Finish UCR, indicate the type of reaction, name the reaction products

Na 2 O + H 2 O =

N 2 O 5 + H 2 O =

CaO + HNO 3 =

NaOH + P 2 O 5 \u003d

K 2 O + CO 2 \u003d

Cu (OH) 2 \u003d? +?

4. Carry out the transformations according to the scheme:

1) K → K 2 O → KOH → K 2 SO 4

2) S → SO 2 → H 2 SO 3 → Na 2 SO 3

3) P → P 2 O 5 → H 3 PO 4 → K 3 PO 4