Non-salt-forming (indifferent, indifferent) oxides CO, SiO, N 2 0, NO.

Salt-forming oxides:

Basic. Oxides whose hydrates are bases. Metal oxides with oxidation states +1 and +2 (less often +3). Examples: Na 2 O - sodium oxide, CaO - calcium oxide, CuO - copper (II) oxide, CoO - cobalt (II) oxide, Bi 2 O 3 - bismuth (III) oxide, Mn 2 O 3 - manganese (III) oxide ).

Amphoteric. Oxides whose hydrates are amphoteric hydroxides. Metal oxides with oxidation states +3 and +4 (less often +2). Examples: Al 2 O 3 - aluminum oxide, Cr 2 O 3 - chromium (III) oxide, SnO 2 - tin (IV) oxide, MnO 2 - manganese (IV) oxide, ZnO - zinc oxide, BeO - beryllium oxide.

Acidic. Oxides whose hydrates are oxygen-containing acids. Non-metal oxides. Examples: P 2 O 3 - phosphorus oxide (III), CO 2 - carbon oxide (IV), N 2 O 5 - nitrogen oxide (V), SO 3 - sulfur oxide (VI), Cl 2 O 7 - chlorine oxide ( VII). Metal oxides with oxidation states +5, +6 and +7. Examples: Sb 2 O 5 - antimony (V) oxide. CrOz - chromium (VI) oxide, MnOz - manganese (VI) oxide, Mn 2 O 7 - manganese (VII) oxide.

Change in the nature of oxides with increasing oxidation state of the metal

Physical properties

Oxides are solid, liquid and gaseous, of different colors. For example: copper (II) oxide CuO is black, calcium oxide CaO is white - solids. Sulfur oxide (VI) SO 3 is a colorless volatile liquid, and carbon monoxide (IV) CO 2 is a colorless gas under ordinary conditions.

State of aggregation

CaO, CuO, Li 2 O and other basic oxides; ZnO, Al 2 O 3, Cr 2 O 3 and other amphoteric oxides; SiO 2, P 2 O 5, CrO 3 and other acid oxides.

SO 3, Cl 2 O 7, Mn 2 O 7, etc.

Gaseous:

CO 2, SO 2, N 2 O, NO, NO 2, etc.

Solubility in water

Soluble:

a) basic oxides of alkali and alkaline earth metals;

b) almost all acid oxides (exception: SiO 2).

Insoluble:

a) all other basic oxides;

b) all amphoteric oxides

Chemical properties

1. Acid-base properties

Common properties of basic, acidic and amphoteric oxides are acid-base interactions, which are illustrated by the following diagram:

(only for oxides of alkali and alkaline earth metals) (except SiO 2).

Amphoteric oxides, having the properties of both basic and acidic oxides, interact with strong acids and alkalis:

2. Redox properties

If an element has a variable oxidation state (s.o.), then its oxides with low s. O. can exhibit reducing properties, and oxides with high c. O. - oxidative.

Examples of reactions in which oxides act as reducing agents:

Oxidation of oxides with low c. O. to oxides with high c. O. elements.

2C +2 O + O 2 = 2C +4 O 2

2S +4 O 2 + O 2 = 2S +6 O 3

2N +2 O + O 2 = 2N +4 O 2

Carbon (II) monoxide reduces metals from their oxides and hydrogen from water.

C +2 O + FeO = Fe + 2C +4 O 2

C +2 O + H 2 O = H 2 + 2C +4 O 2

Examples of reactions in which oxides act as oxidizing agents:

Reduction of oxides with high o. elements to oxides with low c. O. or to simple substances.

C +4 O 2 + C = 2C +2 O

2S +6 O 3 + H 2 S = 4S +4 O 2 + H 2 O

C +4 O 2 + Mg = C 0 + 2MgO

Cr +3 2 O 3 + 2Al = 2Cr 0 + 2Al 2 O 3

Cu +2 O + H 2 = Cu 0 + H 2 O

The use of oxides of low-active metals for the oxidation of organic substances.

Some oxides in which the element has an intermediate c. o., capable of disproportionation;

For example:

2NO 2 + 2NaOH = NaNO 2 + NaNO 3 + H 2 O

Methods of obtaining

1. Interaction of simple substances - metals and non-metals - with oxygen:

4Li + O 2 = 2Li 2 O;

2Cu + O 2 = 2CuO;

4P + 5O 2 = 2P 2 O 5

2. Dehydration of insoluble bases, amphoteric hydroxides and some acids:

Cu(OH) 2 = CuO + H 2 O

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

H 2 SO 3 = SO 2 + H 2 O

H 2 SiO 3 = SiO 2 + H 2 O

3. Decomposition of some salts:

2Cu(NO 3) 2 = 2CuO + 4NO 2 + O 2

CaCO 3 = CaO + CO 2

(CuOH) 2 CO 3 = 2CuO + CO 2 + H 2 O

4. Oxidation of complex substances with oxygen:

CH 4 + 2O 2 = CO 2 + H 2 O

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

4NH 3 + 5O 2 = 4NO + 6H 2 O

5. Reduction of oxidizing acids with metals and non-metals:

Cu + H 2 SO 4 (conc) = CuSO 4 + SO 2 + 2H 2 O

10HNO 3 (conc) + 4Ca = 4Ca(NO 3) 2 + N 2 O + 5H 2 O

2HNO 3 (diluted) + S = H 2 SO 4 + 2NO

6. Interconversions of oxides during redox reactions (see redox properties of oxides).

Oxides are complex substances consisting of two elements, one of which is oxygen. Oxides can be salt-forming and non-salt-forming: one type of salt-forming oxides is basic oxides. How do they differ from other species, and what are their chemical properties?

Salt-forming oxides are divided into basic, acidic and amphoteric oxides. If basic oxides correspond to bases, then acidic oxides correspond to acids, and amphoteric oxides correspond to amphoteric formations. Amphoteric oxides are those compounds that, depending on conditions, can exhibit either basic or acidic properties.

Rice. 1. Classification of oxides.

The physical properties of oxides are very diverse. They can be either gases (CO 2), solids (Fe 2 O 3) or liquid substances (H 2 O).

However, most basic oxides are solids of various colors.

oxides in which elements exhibit their highest activity are called higher oxides. The order of increase in the acidic properties of higher oxides of the corresponding elements in periods from left to right is explained by a gradual increase in the positive charge of the ions of these elements.

Chemical properties of basic oxides

Basic oxides are the oxides to which bases correspond. For example, the basic oxides K 2 O, CaO correspond to the bases KOH, Ca(OH) 2.

Rice. 2. Basic oxides and their corresponding bases.

Basic oxides are formed by typical metals, as well as metals of variable valency in the lowest oxidation state (for example, CaO, FeO), react with acids and acid oxides, forming salts:

CaO (basic oxide) + CO 2 (acid oxide) = CaCO 3 (salt)

FeO (basic oxide)+H 2 SO 4 (acid)=FeSO 4 (salt)+2H 2 O (water)

Basic oxides also react with amphoteric oxides, resulting in the formation of a salt, for example:

Only oxides of alkali and alkaline earth metals react with water:

BaO (basic oxide)+H 2 O (water)=Ba(OH) 2 (alkali earth metal base)

Many basic oxides tend to be reduced to substances consisting of atoms of one chemical element:

3CuO+2NH 3 =3Cu+3H 2 O+N 2

When heated, only oxides of mercury and noble metals decompose:

Rice. 3. Mercury oxide.

List of main oxides:

Oxide name	Chemical formula	Properties
Calcium oxide	CaO	quicklime, white crystalline substance
Magnesium oxide	MgO	white substance, slightly soluble in water
Barium oxide	BaO	colorless crystals with a cubic lattice
Copper oxide II	CuO	black substance practically insoluble in water
	HgO	red or yellow-orange solid
Potassium oxide	K2O	colorless or pale yellow substance
Sodium oxide	Na2O	substance consisting of colorless crystals
Lithium oxide	Li2O	a substance consisting of colorless crystals that have a cubic lattice structure

Modern chemical science represents many different branches, and each of them, in addition to its theoretical basis, has great applied and practical significance. Whatever you touch, everything around you is a chemical product. The main sections are inorganic and organic chemistry. Let's consider what main classes of substances are classified as inorganic and what properties they have.

Main categories of inorganic compounds

These include the following:

1. Oxides.
2. Salt.
3. Grounds.
4. Acids.

Each of the classes is represented by a wide variety of compounds of inorganic nature and is important in almost any structure of human economic and industrial activity. All the main properties characteristic of these compounds, their occurrence in nature and their production are studied in a school chemistry course without fail, in grades 8-11.

There is a general table of oxides, salts, bases, acids, which presents examples of each substance and their state of aggregation and occurrence in nature. Interactions that describe chemical properties are also shown. However, we will look at each of the classes separately and in more detail.

Group of compounds - oxides

4. Reactions as a result of which elements change CO

Me +n O + C = Me 0 + CO

1. Reagent water: formation of acids (SiO 2 exception)

CO + water = acid

2. Reactions with bases:

CO 2 + 2CsOH = Cs 2 CO 3 + H 2 O

3. Reactions with basic oxides: salt formation

P 2 O 5 + 3MnO = Mn 3 (PO 3) 2

4. OVR reactions:

CO 2 + 2Ca = C + 2CaO,

They exhibit dual properties and interact according to the principle of the acid-base method (with acids, alkalis, basic oxides, acid oxides). They do not interact with water.

1. With acids: formation of salts and water

AO + acid = salt + H 2 O

2. With bases (alkalis): formation of hydroxo complexes

Al 2 O 3 + LiOH + water = Li

3. Reactions with acid oxides: obtaining salts

FeO + SO 2 = FeSO 3

4. Reactions with OO: formation of salts, fusion

MnO + Rb 2 O = double salt Rb 2 MnO 2

5. Fusion reactions with alkalis and alkali metal carbonates: formation of salts

Al 2 O 3 + 2LiOH = 2LiAlO 2 + H 2 O

They do not form either acids or alkalis. They exhibit highly specific properties.

Each higher oxide, formed either by a metal or a non-metal, when dissolved in water, gives a strong acid or alkali.

Organic and inorganic acids

In the classical sense (based on the positions of ED - electrolytic dissociation - Svante Arrhenius), acids are compounds that dissociate in an aqueous environment into cations H + and anions of acid residues An -. However, today acids have also been extensively studied in anhydrous conditions, so there are many different theories for hydroxides.

Empirical formulas of oxides, bases, acids, salts consist only of symbols, elements and indices indicating their quantity in the substance. For example, inorganic acids are expressed by the formula H + acid residue n- . Organic substances have a different theoretical representation. In addition to the empirical one, you can write down a full and abbreviated structural formula for them, which will reflect not only the composition and quantity of the molecule, but also the order of the atoms, their connection with each other and the main functional group for carboxylic acids -COOH.

In inorganics, all acids are divided into two groups:

• oxygen-free - HBr, HCN, HCL and others;
• oxygen-containing (oxoacids) - HClO 3 and everything where there is oxygen.

Inorganic acids are also classified by stability (stable or stable - everything except carbonic and sulfurous, unstable or unstable - carbonic and sulfurous). In terms of strength, acids can be strong: sulfuric, hydrochloric, nitric, perchloric and others, as well as weak: hydrogen sulfide, hypochlorous and others.

Organic chemistry offers not the same variety. Acids that are organic in nature are classified as carboxylic acids. Their common feature is the presence of the -COOH functional group. For example, HCOOH (formic), CH 3 COOH (acetic), C 17 H 35 COOH (stearic) and others.

There are a number of acids that are especially carefully emphasized when considering this topic in a school chemistry course.

1. Solyanaya.
2. Nitrogen.
3. Orthophosphoric.
4. Hydrobromic.
5. Coal.
6. Hydrogen iodide.
7. Sulfuric.
8. Acetic or ethane.
9. Butane or oil.
10. Benzoin.

These 10 acids in chemistry are fundamental substances of the corresponding class both in the school course and in general in industry and syntheses.

Properties of inorganic acids

The main physical properties include, first of all, the different state of aggregation. After all, there are a number of acids that have the form of crystals or powders (boric, orthophosphoric) under normal conditions. The vast majority of known inorganic acids are different liquids. Boiling and melting points also vary.

Acids can cause severe burns, as they have the power to destroy organic tissue and skin. Indicators are used to detect acids:

• methyl orange (in normal environment - orange, in acids - red),
• litmus (in neutral - violet, in acids - red) or some others.

The most important chemical properties include the ability to interact with both simple and complex substances.

Chemical properties of inorganic acids

What do they interact with?	Example reaction
1. With simple substances - metals. Mandatory condition: the metal must be in the EHRNM before hydrogen, since metals standing after hydrogen are not able to displace it from the composition of acids. The reaction always produces hydrogen gas and salt.
2. With reasons. The result of the reaction is salt and water. Such reactions of strong acids with alkalis are called neutralization reactions.	Any acid (strong) + soluble base = salt and water
3. With amphoteric hydroxides. Bottom line: salt and water.	2HNO 2 + beryllium hydroxide = Be(NO 2) 2 (medium salt) + 2H 2 O
4. With basic oxides. Result: water, salt.	2HCL + FeO = iron (II) chloride + H 2 O
5. With amphoteric oxides. Final effect: salt and water.	2HI + ZnO = ZnI 2 + H 2 O
6. With salts formed by weaker acids. Final effect: salt and weak acid.	2HBr + MgCO 3 = magnesium bromide + H 2 O + CO 2

When interacting with metals, not all acids react equally. Chemistry (9th grade) at school involves a very shallow study of such reactions, however, even at this level the specific properties of concentrated nitric and sulfuric acid when interacting with metals are considered.

Hydroxides: alkalis, amphoteric and insoluble bases

Oxides, salts, bases, acids - all these classes of substances have a common chemical nature, explained by the structure of the crystal lattice, as well as the mutual influence of atoms in the molecules. However, if it was possible to give a very specific definition for oxides, then this is more difficult to do for acids and bases.

Just like acids, bases, according to the theory of ED, are substances that can decompose in an aqueous solution into metal cations Me n + and anions of hydroxyl groups OH - .

• Soluble or alkali (strong bases that change the color of indicators). Formed by metals of groups I and II. Example: KOH, NaOH, LiOH (that is, elements of only the main subgroups are taken into account);
• Slightly soluble or insoluble (medium strength, do not change the color of the indicators). Example: magnesium hydroxide, iron (II), (III) and others.
• Molecular (weak bases, in an aqueous environment they reversibly dissociate into ion molecules). Example: N 2 H 4, amines, ammonia.
• Amphoteric hydroxides (show dual basic-acid properties). Example: beryllium, zinc and so on.

Each group presented is studied in the school chemistry course in the “Fundamentals” section. Chemistry in grades 8-9 involves a detailed study of alkalis and poorly soluble compounds.

Main characteristic properties of bases

All alkalis and slightly soluble compounds are found in nature in a solid crystalline state. At the same time, their melting temperatures are usually low, and poorly soluble hydroxides decompose when heated. The color of the bases is different. If alkalis are white, then crystals of poorly soluble and molecular bases can be of very different colors. The solubility of most compounds of this class can be found in the table, which presents the formulas of oxides, bases, acids, salts, and shows their solubility.

Alkalies can change the color of indicators as follows: phenolphthalein - crimson, methyl orange - yellow. This is ensured by the free presence of hydroxo groups in the solution. That is why poorly soluble bases do not give such a reaction.

The chemical properties of each group of bases are different.

Chemical properties
Alkalis	Slightly soluble bases	Amphoteric hydroxides
I. Interact with CO (result - salt and water): 2LiOH + SO 3 = Li 2 SO 4 + water II. Interact with acids (salt and water): ordinary neutralization reactions (see acids) III. They interact with AO to form a hydroxo complex of salt and water: 2NaOH + Me +n O = Na 2 Me +n O 2 + H 2 O, or Na 2 IV. They interact with amphoteric hydroxides to form hydroxo complex salts: The same as with AO, only without water V. React with soluble salts to form insoluble hydroxides and salts: 3CsOH + iron (III) chloride = Fe(OH) 3 + 3CsCl VI. React with zinc and aluminum in an aqueous solution to form salts and hydrogen: 2RbOH + 2Al + water = complex with hydroxide ion 2Rb + 3H 2	I. When heated, they can decompose: insoluble hydroxide = oxide + water II. Reactions with acids (result: salt and water): Fe(OH) 2 + 2HBr = FeBr 2 + water III. Interact with KO: Me +n (OH) n + KO = salt + H 2 O	I. React with acids to form salt and water: (II) + 2HBr = CuBr 2 + water II. React with alkalis: result - salt and water (condition: fusion) Zn(OH) 2 + 2CsOH = salt + 2H 2 O III. React with strong hydroxides: the result is salts if the reaction occurs in an aqueous solution: Cr(OH) 3 + 3RbOH = Rb 3

These are most of the chemical properties that bases exhibit. The chemistry of bases is quite simple and follows the general laws of all inorganic compounds.

Class of inorganic salts. Classification, physical properties

Based on the provisions of the ED, salts can be called inorganic compounds that dissociate in an aqueous solution into metal cations Me +n and anions of acidic residues An n-. This is how you can imagine salts. Chemistry gives more than one definition, but this is the most accurate.

Moreover, according to their chemical nature, all salts are divided into:

• Acidic (containing a hydrogen cation). Example: NaHSO 4.
• Basic (containing a hydroxo group). Example: MgOHNO 3, FeOHCL 2.
• Medium (consist only of a metal cation and an acid residue). Example: NaCL, CaSO 4.
• Double (include two different metal cations). Example: NaAl(SO 4) 3.
• Complex (hydroxo complexes, aqua complexes and others). Example: K 2.

The formulas of salts reflect their chemical nature, and also indicate the qualitative and quantitative composition of the molecule.

Oxides, salts, bases, acids have different solubility properties, which can be viewed in the corresponding table.

If we talk about the state of aggregation of salts, then we need to notice their uniformity. They exist only in solid, crystalline or powdery states. The color range is quite varied. Solutions of complex salts, as a rule, have bright, saturated colors.

Chemical interactions for the class of medium salts

They have similar chemical properties as bases, acids, and salts. Oxides, as we have already examined, are somewhat different from them in this factor.

In total, 4 main types of interactions can be distinguished for medium salts.

I. Interaction with acids (only strong from the point of view of ED) with the formation of another salt and a weak acid:

KCNS + HCL = KCL + HCNS

II. Reactions with soluble hydroxides producing salts and insoluble bases:

CuSO 4 + 2LiOH = 2LiSO 4 soluble salt + Cu(OH) 2 insoluble base

III. Reaction with another soluble salt to form an insoluble salt and a soluble one:

PbCL 2 + Na 2 S = PbS + 2NaCL

IV. Reactions with metals located in the EHRNM to the left of the one that forms the salt. In this case, the reacting metal should not interact with water under normal conditions:

Mg + 2AgCL = MgCL 2 + 2Ag

These are the main types of interactions that are characteristic of medium salts. The formulas of complex, basic, double and acidic salts speak for themselves about the specificity of the chemical properties exhibited.

The formulas of oxides, bases, acids, salts reflect the chemical essence of all representatives of these classes of inorganic compounds, and in addition, give an idea of ​​the name of the substance and its physical properties. Therefore, special attention should be paid to their writing. A huge variety of compounds is offered to us by the generally amazing science of chemistry. Oxides, bases, acids, salts - this is only part of the immense diversity.

Oxides are called complex substances whose molecules include oxygen atoms in oxidation state - 2 and some other element.

can be obtained through the direct interaction of oxygen with another element, or indirectly (for example, during the decomposition of salts, bases, acids). Under normal conditions, oxides come in solid, liquid and gaseous states; this type of compound is very common in nature. Oxides are found in the Earth's crust. Rust, sand, water, carbon dioxide are oxides.

They are either salt-forming or non-salt-forming.

Salt-forming oxides- These are oxides that form salts as a result of chemical reactions. These are oxides of metals and non-metals, which, when interacting with water, form the corresponding acids, and when interacting with bases, the corresponding acidic and normal salts. For example, Copper oxide (CuO) is a salt-forming oxide, because, for example, when it reacts with hydrochloric acid (HCl), a salt is formed:

CuO + 2HCl → CuCl 2 + H 2 O.

As a result of chemical reactions, other salts can be obtained:

CuO + SO 3 → CuSO 4.

Non-salt-forming oxides These are oxides that do not form salts. Examples include CO, N 2 O, NO.

Salt-forming oxides, in turn, are of 3 types: basic (from the word « base » ), acidic and amphoteric.

Basic oxides These metal oxides are called those that correspond to hydroxides belonging to the class of bases. Basic oxides include, for example, Na 2 O, K 2 O, MgO, CaO, etc.

Chemical properties of basic oxides

1. Water-soluble basic oxides react with water to form bases:

Na 2 O + H 2 O → 2NaOH.

2. React with acid oxides, forming the corresponding salts

Na 2 O + SO 3 → Na 2 SO 4.

3. React with acids to form salt and water:

CuO + H 2 SO 4 → CuSO 4 + H 2 O.

4. React with amphoteric oxides:

Li 2 O + Al 2 O 3 → 2LiAlO 2.

If the composition of the oxides contains a non-metal or a metal exhibiting the highest valence (usually from IV to VII) as the second element, then such oxides will be acidic. Acidic oxides (acid anhydrides) are those oxides that correspond to hydroxides belonging to the class of acids. These are, for example, CO 2, SO 3, P 2 O 5, N 2 O 3, Cl 2 O 5, Mn 2 O 7, etc. Acidic oxides dissolve in water and alkalis, forming salt and water.

Chemical properties of acid oxides

1. React with water to form an acid:

SO 3 + H 2 O → H 2 SO 4.

But not all acidic oxides react directly with water (SiO 2, etc.).

2. React with based oxides to form a salt:

CO 2 + CaO → CaCO 3

3. React with alkalis, forming salt and water:

CO 2 + Ba(OH) 2 → BaCO 3 + H 2 O.

Part amphoteric oxide includes an element that has amphoteric properties. Amphotericity refers to the ability of compounds to exhibit acidic and basic properties depending on conditions. For example, zinc oxide ZnO can be either a base or an acid (Zn(OH) 2 and H 2 ZnO 2). Amphotericity is expressed in the fact that, depending on the conditions, amphoteric oxides exhibit either basic or acidic properties.

Chemical properties of amphoteric oxides

1. React with acids to form salt and water:

ZnO + 2HCl → ZnCl 2 + H 2 O.

2. React with solid alkalis (during fusion), forming as a result of the reaction salt - sodium zincate and water:

ZnO + 2NaOH → Na 2 ZnO 2 + H 2 O.

When zinc oxide interacts with an alkali solution (the same NaOH), another reaction occurs:

ZnO + 2 NaOH + H 2 O => Na 2.

Coordination number is a characteristic that determines the number of nearby particles: atoms or ions in a molecule or crystal. Each amphoteric metal has its own coordination number. For Be and Zn it is 4; For and Al it is 4 or 6; For and Cr it is 6 or (very rarely) 4;

Amphoteric oxides are usually insoluble in water and do not react with it.

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In lesson 32 " Chemical properties of oxides" from the course " Chemistry for dummies“We will learn about all the chemical properties of acidic and basic oxides, consider what they react with and what is formed.

Since the chemical composition of acidic and basic oxides is different, they differ in their chemical properties.

1. Chemical properties of acid oxides

a) Interaction with water
You already know that the products of the interaction of oxides with water are called “hydroxides”:

Since the oxides that enter into this reaction are divided into acidic and basic, the hydroxides formed from them are also divided into acidic and basic. Thus, acidic oxides (except SiO2) react with water to form acidic hydroxides, which are oxygen-containing acids:

Each acidic oxide corresponds to an oxygen-containing acid, which is classified as acidic hydroxides. Despite the fact that silicon oxide SiO 2 does not react with water, the acid H 2 SiO 3 also corresponds to it, but it is obtained by other methods.

b) Interaction with alkalis
All acid oxides react with alkalis according to the general scheme:

In the resulting salt, the valency of the metal atoms is the same as in the original alkali. Besides, the salt contains the remainder of the acid that corresponds to the given acid oxide.

For example, if the acidic oxide CO 2 reacts, which corresponds to the acid H 2 CO3 CO3, whose valence, as you already know, is II:

If the acidic oxide N 2 O 5 enters into the reaction, which corresponds to the acid H NO 3(indicated in square brackets), then the resulting salt will contain the remainder of this acid - NO 3 with valence equal to I:

Since all acidic oxides react with alkalis to form salts and water, these oxides can be given another definition.

Acidic are called oxides that react with alkalis to form salts and water.

c) Reactions with basic oxides

Acidic oxides react with basic oxides to form salts according to the general scheme:

In the resulting salt, the valency of the metal atoms is the same as in the original basic oxide. It should be remembered that the salt contains the remainder of the acid that corresponds to the acid oxide that enters into the reaction. For example, if the acidic oxide SO 3 reacts, which corresponds to the acid H 2 SO 4(indicated in square brackets), then the salt will include the remainder of this acid - SO 4, whose valency is II:

If the acidic oxide P 2 O 5 enters into the reaction, which corresponds to the acid H 3 RO 4, then the resulting salt will contain the remainder of this acid - PO 4 with a valence of III.

2. Chemical properties of basic oxides

a) Interaction with water

You already know that as a result of the interaction of basic oxides with water, basic hydroxides are formed, which are otherwise called bases:

These basic oxides include the following oxides: Li 2 O, Na 2 O, K 2 O, CaO, BaO.

When writing equations for the corresponding reactions, it should be remembered that the valence of metal atoms in the resulting base is equal to its valency in the original oxide.

Basic oxides formed by metals such as Cu, Fe, Cr do not react with water. The corresponding bases are obtained in other ways.

b) Interaction with acids

Almost all basic oxides react with acids to form salts according to the general scheme:

It should be remembered that in the resulting salt, the valency of the metal atoms is the same as in the original oxide, and the valency of the acid residue is the same as in the original acid.

Since all basic oxides react with acids to form salts and water, these oxides can be given another definition.

Main are called oxides that react with acids to form salts and water.

c) Interaction with acid oxides

Basic oxides react with acidic oxides to form salts according to the general scheme:

In the resulting salt, the valency of the metal atoms is the same as in the original basic oxide. In addition, you should remember that the salt contains the remainder of the acid that corresponds to the acid oxide that reacts. For example, if the acidic oxide N2O5 reacts, which corresponds to the acid H NO 3, then the salt will contain the remainder of this acid - NO 3, whose valency, as you already know, is I.

Since the acidic and basic oxides we have considered form salts as a result of various reactions, they are called salt-forming. There is, however, a small group of oxides that do not form salts in similar reactions, which is why they are called non-salt-forming.

Brief conclusions of the lesson:

1. All acidic oxides react with alkalis to form salts and water.
2. All basic oxides react with acids to form salts and water.
3. Acidic and basic oxides are salt-forming. Non-salt-forming oxides - CO, N 2 O, NO.
4. Bases and oxygen-containing acids are hydroxides.

Hope lesson 32" Chemical properties of oxides"was clear and informative. If you have any questions, write them in the comments.