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Oxides composition obtaining properties application briefly. What are oxides? Task

Formula of oxides necessary for the possibility of solving problems and understanding the possible options for compounds of chemical elements. General formula of oxides- E x O w. Oxygen has the second largest electronegativity value after fluorine, which is the reason why most compounds of chemical elements with oxygen are oxides.

By oxide classification, salt-forming oxides are those oxides that can interact with acids or bases to form the corresponding salt and water. Salt-forming oxides are called:

basic oxides, often formed from metals with an oxidation state of +1, +2. May react with acids, acid oxides, amphoteric oxides, water (alkali and alkaline earth metal oxides only). The basic oxide element becomes a cation in the resulting salt. Na 2 O, CaO, MgO, CuO.

Basic oxide + strong acid → salt + water: CuO + H 2 SO 4 → CuSO 4 + H 2 O
Strong base oxide + water → hydroxide: CaO + H 2 O → Ca(OH) 2
Strong base oxide + acid oxide → salt: CaO + Mn 2 O 7 → Ca(MnO 4) 2
Basic oxide + hydrogen → metal + water: CuO + H 2 → Cu + H 2 O

Note: metal is less active than aluminium.

Acid oxides- oxides of non-metals and metals in the oxidation state +5 - +7. They can react with water, alkalis, basic oxides, amphoteric oxides. The acid oxide element is part of the anion of the resulting salt. Mn 2 O 7, CrO 3, SO 3, N 2 O 5.

Acid oxide + water → acid: SO 3 + H 2 O → H 2 SO 4. Some oxides, such as SiO 2 , cannot react with water, so their acids are obtained indirectly.
Acid oxide + basic oxide → salt: CO 2 + CaO → CaCO 3
Acid oxide + base → salt + water: SO 2 + 2NaOH → Na 2 SO 3 + H 2 O. If the acid oxide is an anhydride of a polybasic acid, the formation of acid or medium salts is possible: Ca (OH) 2 + CO 2 → CaCO 3 ↓ + H 2 O, CaCO 3 + H 2 O + CO 2 → Ca (HCO 3) 2
Non-volatile oxide + salt 1 → salt 2 + volatile oxide: SiO 2 + Na 2 CO 3 → Na 2 SiO 3 + CO 2
Acid anhydride 1 + anhydrous oxygen-containing acid 2 → Acid anhydride 2 + anhydrous oxygen-containing acid 1: 2P 2 O 5 + 4HClO 4 → 4HPO 3 + 2Cl 2 O 7

Amphoteric oxides, form metals with an oxidation state of +3 to +5 (amphoteric oxides also include BeO, ZnO, PbO, SnO). React with acids, alkalis, acidic and basic oxides.

When interacting with a strong acid or acid oxide, they exhibit basic properties: ZnO + 2HCl → ZnCl 2 + H 2 O

When interacting with a strong base or basic oxide, they exhibit acid properties:

ZnO + 2KOH + H 2 O → K 2 (in aqueous solution).
ZnO + 2KOH → K 2 ZnO 2 (during fusion).

Non-salt-forming oxides do not react with either acids or bases, which means that they do not form salts. N 2 O, NO, CO, SiO.

In accordance with the IUPAC nomenclature, the names of oxides are made up of the word oxide and the name of the second chemical element (with less electronegativity) in the genitive case:

Calcium oxide - CaO.

If an element can form several oxides, then the oxidation state of the element should be indicated in their names:

Fe 2 O 3 - iron oxide (III);
MnO 2 - manganese (IV) oxide.

You can use Latin prefixes to denote the number of elemental atoms that make up an oxide molecule:

Na 2 O - disodium oxide;
CO - carbon monoxide;
CO 2 - carbon dioxide.

The trivial names of some oxides are also often used:

Names of oxides.

Oxide Formula	Systematic name	Trivial name
		Carbon monoxide
		Carbon dioxide
	magnesium oxide	Magnesia
	calcium oxide	Quicklime
	Iron(II) oxide	ferrous oxide
Fe2O3	Iron(III) oxide	iron oxide
	Phosphorus(V) oxide	Phosphoric anhydride
H 2 O 2	Hydrogen peroxide
SO2	Sulfur(IV) oxide
Ag2O	Silver(I) oxide
Cu 2 O 3	Copper(III) oxide	dimedium trioxide
CuO	Copper(II) oxide	copper oxide
Cu2O	Copper(I) oxide	Cuprous oxide, copper hemoxide, dimedium oxide

Write a formula for oxides.

At formulating oxide the first element is the element whose oxidation state is +, and the second is the element with a negative oxidation state. For oxides, it is always oxygen.

The next steps for formulating the oxide formula are:

1. Arrange the oxidation states (oxidation state) for each atom. Oxygen in oxides always has an oxidation state of -2 (minus two).

2. In order to correctly find out the oxidation state of the second element, you need to look at the table of possible oxidation states of some elements.

When composing the names of substances, I most often use the Russian names of the elements, for example, dioxygen, xenon difluoride, potassium selenate. Sometimes, for some elements, the roots of their Latin names are introduced into derivative terms:

Names of elements in formulating oxides.

Ag - argent
As - ars, arsene	Ni - nikkol
	O - ox, oxygen
C - carb, carbon


H - hydr, hydrogen	Si - sil, silic, silic
Hg - mercur
Mn - manganese

For example: carbonate, manganate, oxide, sulfide, silicate.

The names of simple substances consist of one word - the name of a chemical element with a numerical prefix, for example:

The following numeric prefixes are used:

Numerical prefixes in formulating oxides.

An indefinite number is indicated by a numerical prefix n- poly.

The names of common acid hydroxides consist of two words: their own name with the ending "aya" and the group word "acid". Here are the formulas and proper names of common acid hydroxides and their acid residues (a dash means that the hydroxide is not known in free form or in an acidic aqueous solution):

Formulas and proper names of common acid hydroxides and their acid residues.

acid hydroxide	acid residue
HAsO 2 - metaarsenous	AsO 2 - - metaarsenite
H 3 AsO 3 - orthoarsenic	AsO 3 3- - orthoarsenite
H 3 AsO 4 - arsenic	AsO 4 3- - arsenate
	B 4 O 7 2- - tetraborate
	ВiО 3 - - bismuthate
HBrO - bromine	BrO - - hypobromite
HBrO 3 - bromine	BrO 3 - - bromate
H 2 CO 3 - coal	CO 3 2- - carbonate
HClO - hypochlorous	ClO- - hypochlorite
HClO 2 - chloride	ClO 2 - - chlorite
HClO 3 - chlorine	ClO 3 - - chlorate
HClO 4 - chlorine	ClO 4 - - perchlorate
H 2 CrO 4 - chrome	CrO 4 2- - chromate
	НCrO 4 - - hydrochromate
H 2 Cr 2 O 7 - dichromic	Cr 2 O 7 2- - dichromate
	FeO 4 2- - ferrate
HIO 3 - iodine	IO3- - iodate
HIO 4 - metaiodine	IO 4 - - metaperiodate
H 5 IO 6 - orthoiodic	IO 6 5- - orthoperiodate
HMnO 4 - manganese	MnO4- - permanganate
	MnO 4 2- - manganate
	MoO 4 2- - molybdate
HNO 2 - nitrogenous	NO 2 - - nitrite
HNO 3 - nitrogen	NO 3 - - nitrate
HPO 3 - metaphosphoric	PO 3 - - metaphosphate
H 3 PO 4 - orthophosphoric	PO 4 3- - orthophosphate
	HPO 4 2- - hydrogen orthophosphate
	H 2 PO 4 - - dihydrootophosphate
H 4 P 2 O 7 - diphosphoric	P 2 O 7 4- - diphosphate
	ReO 4 - - perrhenate
	SO 3 2- - sulfite
	HSO 3 - - hydrosulfite
H 2 SO 4 - sulfuric	SO 4 2- - sulfate
	НSO 4 - - hydrosulphate
H 2 S 2 O 7 - dispersed	S 2 O 7 2- - disulfate
H 2 S 2 O 6 (O 2) - peroxodisulfur	S 2 O 6 (O 2) 2- - peroxodisulfate
H 2 SO 3 S - thiosulfuric	SO 3 S 2- - thiosulfate
H 2 SeO 3 - selenium	SeO 3 2- - selenite
H 2 SeO 4 - selenium	SeO 4 2- - selenate
H 2 SiO 3 - metasilicon	SiO 3 2- - metasilicate
H 4 SiO 4 - orthosilicon	SiO 4 4- - orthosilicate
H 2 TeO 3 - telluric	TeO 3 2- - tellurite
H 2 TeO 4 - metatellurium	TeO 4 2- - metatellurate
H 6 TeO 6 - orthotelluric	TeO 6 6- - orthotellurate
	VO3- - metavanadate
	VO 4 3- - orthovanadate
	WO 4 3- - tungstate

Less common acid hydroxides are named according to the nomenclature rules for complex compounds, for example.

If you were not fond of chemistry at school, you are unlikely to immediately remember what oxides are and what their role is in the environment. It is actually a fairly common type of compound that occurs most frequently in the environment in the form of water, rust, carbon dioxide, and sand. Oxides also include minerals - a type of rock that has a crystalline structure.

Definition

Oxides are chemical compounds whose formula contains at least one oxygen atom and atoms of other chemical elements. Metal oxides generally contain oxygen anions in the -2 oxidation state. A significant part of the Earth's crust consists of solid oxides, which arose in the process of oxidation of elements with oxygen from air or water. In the process of burning hydrocarbons, two main oxides of carbon are formed: carbon monoxide (carbon monoxide, CO) and carbon dioxide (carbon dioxide, CO 2).

Classification of oxides

All oxides are usually divided into two large groups:

salt-forming oxides;
non-salt-forming oxides.

Salt-forming oxides are chemicals that, in addition to oxygen, contain metal and non-metal elements that form acids when in contact with water, and when combined with bases, salts.

Salt-forming oxides, in turn, are divided into:

basic oxides, in which, upon oxidation, the second element (1, 2 and sometimes 3-valent metal) becomes a cation (Li 2 O, Na 2 O, K 2 O, CuO, Ag 2 O, MgO, CaO, SrO, BaO, HgO , MnO, CrO, NiO, Fr 2 O, Cs 2 O, Rb 2 O, FeO);
acid oxides, in which, during the formation of a salt, the second element is attached to a negatively charged oxygen atom (CO 2, SO 2, SO 3, SiO 2, P 2 O 5, CrO 3, Mn 2 O 7, NO 2, Cl 2 O 5, Cl2O3);
amphoteric oxides, in which the second element (3 and 4-valent metals or such exceptions as zinc oxide, beryllium oxide, tin oxide and lead oxide) can become both a cation and join an anion (ZnO, Cr 2 O 3, Al 2 O 3 , SnO, SnO 2 , PbO, PbO 2 , TiO 2 , MnO 2 , Fe 2 O 3 , BeO).

Non-salt-forming oxides exhibit neither acidic nor basic nor amphoteric properties and, as the name suggests, do not form salts (CO, NO, NO 2 , (FeFe 2)O 4).

Properties of oxides

Oxygen atoms in oxides are highly reactive. Due to the fact that the oxygen atom is always negatively charged, it forms stable chemical bonds with almost all elements, which leads to a wide variety of oxides.
Noble metals such as gold and platinum are valued because they do not oxidize naturally. Corrosion of metals is formed as a result of hydrolysis or oxidation by oxygen. The combination of water and oxygen only speeds up the rate of the reaction.
In the presence of water and oxygen (or simply air), the oxidation reaction of some elements, such as sodium, occurs rapidly and can be dangerous to humans.
Oxides create a protective oxide film on the surface. An example is aluminum foil, which, due to the coating of a thin film of aluminum oxide, corrodes much more slowly.
The oxides of most metals have a polymeric structure, due to which they are not destroyed by the action of solvents.
Oxides dissolve under the action of acids and bases. Oxides that can react with both acids and bases are called amphoteric. Metals, as a rule, form basic oxides, non-metals - acidic oxides, and amphoteric oxides are obtained from alkali metals (metalloids).
The amount of metal oxide can be reduced by the action of some organic compounds. Such redox reactions underlie many important chemical transformations, such as the detoxification of drugs by P450 enzymes and the production of ethylene oxide, which is then used to make antifreeze.

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August 6, 2018

Each student met with the concept of "oxide" in chemistry lessons. From this word alone, the object began to seem something indescribably terrible. But there is nothing wrong here. Higher oxides are substances that contain compounds of simple substances with oxygen (in the -2 oxidation state). It is worth noting that they react with:

O 2 (oxygen), in the event that the element is not in the highest CO. For example, SO 2 reacts with oxygen (because CO is +4), but SO 3 does not (because it is in the highest oxidation state +6).
H 2 (hydrogen) and C (carbon). Only some oxides react.
Water in the event that a soluble alkali or acid is obtained.

All oxides react with salts and non-metals (with the exception of the above substances).

It is worth noting that some substances (for example, nitric oxide, iron oxide and chlorine oxide) have their own characteristics, i.e. their chemical characteristics may differ from other substances.

Classification of oxides

They are divided into two branches: those who can form salt, and those who cannot form it.

Examples of formulas for higher oxides that do not form salts: NO (bivalent nitric oxide; colorless gas formed during thunderstorms), CO (carbon monoxide), N 2 O (univalent nitric oxide), SiO (silicon oxide), S 2 O (sulfur oxide), water.

These compounds can react with bases, acids and salt-forming oxides. But when these substances react, salts are never formed. For example:

CO (carbon monoxide) + NaOH (sodium hydroxide) = HCOONa (sodium formate)

Salt-forming oxides are divided into three types: acidic, base and amphoteric oxides.

Acid oxides

An acidic higher oxide is a salt-forming oxide that corresponds to an acid. For example, hexavalent sulfur oxide (SO 3) has a corresponding chemical compound - H 2 SO 4. These elements react with basic and amphoteric oxides, bases and water. A salt or acid is formed.

With alkaline oxides: CO 2 (carbon dioxide) + MgO (magnesium oxide) = MgCO 3 (bitter salt).
With amphoteric oxides: P 2 O 5 (phosphorus oxide) + Al 2 O 3 (aluminum oxide) \u003d 2AlPO 4 (aluminum phosphate or orthophosphate).
With bases (alkalis): CO 2 (carbon dioxide) + 2NaOH (caustic soda) \u003d Na 2 CO 3 (sodium carbonate or soda ash) + H 2 O (water).
With water: CO 2 (carbon dioxide) + H 2 O \u003d H 2 CO 3 (carbonic acid, after the reaction it instantly decomposes into carbon dioxide and water).

Oxides of acids do not react with each other.

Basic oxides

The basic higher oxide is the salt-forming oxide of the metal to which the base corresponds. Calcium oxide (CaO) corresponds to calcium hydroxide (Ca(OH) 2). These substances interact with oxides of an acidic and amphoteric nature, acids (with the exception of H 2 SiO 3, since silicic acid is insoluble) and water.

With acidic oxides: CaO (calcium oxide) + CO 2 (carbon dioxide) = CaCO 3 (calcium carbonate or ordinary chalk).
With amphoteric oxide: CaO (calcium oxide) + Al 2 O 3 (aluminum oxide) = Ca (AlO 2) 2 (calcium aluminate).
With acids: CaO (calcium oxide) + H 2 SO 4 (sulfuric acid) = CaSO 4 (calcium sulfate or gypsum) + H 2 O.
With water: CaO (calcium oxide) + H 2 O = Ca (OH) 2 (calcium hydroxide or lime slaking reaction).

They don't interact with each other.

Amphoteric oxides

Amphoteric higher oxide is the oxide of an amphoteric metal. Depending on the conditions, it can show basic or acidic properties. For example, the formulas of higher oxides that exhibit amphoteric properties: ZnO (zinc oxide), Al 2 O 3 (alumina). Amphoteric oxides react with alkalis, acids (also with the exception of silicic acid), basic and acidic oxides.

With bases: ZnO (zinc oxide) + 2NaOH (sodium base) = Na 2 ZnO 2 (zinc and sodium double salt) + H 2 O.
With acids: Al 2 O 3 (aluminum oxide) + 6HCl (hydrochloric acid) = 2AlCl 3 (aluminum chloride or aluminum chloride) + 3H 2 O.
With acid oxides: Al 2 O 3 (aluminum oxide) + 3SO 3 (hexavalent sulfur oxide) = Al 2 (SO 4) 3 (aluminum alum).
With basic oxides: Al 2 O 3 (aluminum oxide) + Na 2 O (sodium oxide) = 2NaAlO 2 (sodium aluminate).

Elements of higher oxides of an amphoteric nature do not interact with each other and with water.

Source: fb.ru

Actual

Miscellaneous
Miscellaneous

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 (rarely +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 (rarely +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.

Acid. Oxides whose hydrates are oxygen-containing acids. Oxides of non-metals. Examples: P 2 O 3 - phosphorus oxide (III), CO 2 - carbon monoxide (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 an increase in the degree of oxidation of the metal

Physical Properties

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

State of aggregation

CaO, СuО, 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 and others.

Gaseous:

CO 2 , SO 2 , N 2 O, NO, NO 2 and others.

Solubility in water

Soluble:

a) basic oxides of alkali and alkaline earth metals;

b) almost all acidic 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 scheme:

(only for oxides of alkali and alkaline earth metals) (except for 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 s. O. to oxides with high s. O. elements.

2C +2 O + O 2 \u003d 2C +4 O 2

2S +4 O 2 + O 2 \u003d 2S +6 O 3

2N +2 O + O 2 \u003d 2N +4 O 2

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

C +2 O + FeO \u003d Fe + 2C +4 O 2

C +2 O + H 2 O \u003d H 2 + 2C +4 O 2

Examples of reactions in which oxides act as oxidizing agents:

Recovery of oxides with high o.d. elements to oxides with low s. O. or down to simple substances.

C +4 O 2 + C \u003d 2C +2 O

2S +6 O 3 + H 2 S \u003d 4S +4 O 2 + H 2 O

C +4 O 2 + Mg \u003d C 0 + 2MgO

Cr +3 2 O 3 + 2Al \u003d 2Cr 0 + 2Al 2 O 3

Cu +2 O + H 2 \u003d Cu 0 + H 2 O

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 \u003d NaNO 2 + NaNO 3 + H 2 O

How to get

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

4Li + O 2 = 2Li 2 O;

2Cu + O 2 \u003d 2CuO;

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

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

Cu(OH) 2 \u003d CuO + H 2 O

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

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

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

3. Decomposition of some salts:

2Cu(NO 3) 2 \u003d 2CuO + 4NO 2 + O 2

CaCO 3 \u003d CaO + CO 2

(CuOH) 2 CO 3 \u003d 2CuO + CO 2 + H 2 O

4. Oxidation of complex substances with oxygen:

CH 4 + 2O 2 \u003d CO 2 + H 2 O

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

4NH 3 + 5O 2 \u003d 4NO + 6H 2 O

5. Recovery of oxidizing acids by 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 (razb) + S \u003d H 2 SO 4 + 2NO

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

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 valency 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 valence I And II (except ZnO - zinc oxide and BeO – beryllium oxide):

2). Acid oxides are oxides, which correspond to acids. 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 valence 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 valence 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 down 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 (p. Compound)

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 down 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 name them.

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: