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A chemical formula reflects information about the composition and structure of substances using chemical symbols, numbers and dividing symbols of brackets. Currently, the following types of chemical formulas are distinguished: The simplest formula. Can be obtained by experienced... ... Wikipedia
A chemical formula reflects information about the composition and structure of substances using chemical symbols, numbers and dividing symbols of brackets. Currently, the following types of chemical formulas are distinguished: The simplest formula. Can be obtained by experienced... ... Wikipedia
A chemical formula reflects information about the composition and structure of substances using chemical symbols, numbers and dividing symbols of brackets. Currently, the following types of chemical formulas are distinguished: The simplest formula. Can be obtained by experienced... ... Wikipedia
A chemical formula reflects information about the composition and structure of substances using chemical symbols, numbers and dividing symbols of brackets. Currently, the following types of chemical formulas are distinguished: The simplest formula. Can be obtained by experienced... ... Wikipedia
Main article: Inorganic compounds List of inorganic compounds by element informational list of inorganic compounds presented in alphabetical order (by formula) for each substance, hydrogen acids of the elements (if ... ... Wikipedia
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8.1. What is chemical nomenclature
Chemical nomenclature developed gradually over several centuries. As chemical knowledge accumulated, it changed several times. It is being refined and developed even now, which is connected not only with the imperfection of some nomenclature rules, but also with the fact that scientists are constantly discovering new and new compounds, which sometimes turn out to be named (and sometimes even made formulas), using existing rules impossible. The nomenclature rules currently accepted by the scientific community around the world are contained in a multi-volume publication: “IUPAC Nomenclature Rules for Chemistry”, the number of volumes in which is continuously increasing.
You are already familiar with the types of chemical formulas, as well as some of the rules for their composition. What are the names of chemical substances?
Using nomenclature rules, you can create systematic Name substances.
For many substances, in addition to systematic ones, traditional, so-called trivial titles. When they appeared, these names reflected certain properties of substances, methods of preparation, or contained the name of what the substance was isolated from. Compare the systematic and trivial names of the substances given in Table 25.
All names of minerals (natural substances that make up rocks) are also trivial, for example: quartz (SiO 2); rock salt, or halite (NaCl); zinc blende, or sphalerite (ZnS); magnetic iron ore, or magnetite (Fe 3 O 4); pyrolusite (MnO 2); fluorspar, or fluorite (CaF 2) and many others.
Table 25. Systematic and trivial names of some substances
Systematic name |
Trivial name |
|
NaCl | Sodium chloride | Salt |
Na 2 CO 3 | Sodium carbonate | Soda, soda ash |
NaHCO3 | Sodium bicarbonate | Baking soda |
CaO | Calcium oxide | Quicklime |
Ca(OH)2 | Calcium hydroxide | Slaked lime |
NaOH | Sodium hydroxide | Caustic soda, caustic soda, caustic |
KOH | Potassium hydroxide | Caustic potassium |
K2CO3 | Potassium carbonate | Potash |
CO2 | Carbon dioxide | Carbon dioxide, carbon dioxide |
CO | Carbon monoxide | Carbon monoxide |
NH4NO3 | Ammonium nitrate | Ammonium nitrate |
KNO 3 | Potassium nitrate | Potassium nitrate |
KClO3 | Potassium chlorate | Bertholet's salt |
MgO | Magnesium oxide | Magnesia |
For some of the most well-known or widespread substances, only trivial names are used, for example: water, ammonia, methane, diamond, graphite and others. In this case, such trivial names are sometimes called special.
You will learn how the names of substances belonging to different classes are composed in the following paragraphs.
Sodium carbonate Na 2 CO 3 . The technical (trivial) name is soda ash (that is, calcined) or simply “soda.” The white substance, thermally very stable (melts without decomposition), dissolves well in water, partially reacting with it, and an alkaline environment is created in the solution. Sodium carbonate is an ionic compound with a complex anion, the atoms of which are linked together by covalent bonds. Soda was previously widely used in everyday life for washing clothes, but has now been completely replaced by modern washing powders. Sodium carbonate is obtained using a rather complex technology from sodium chloride, and is used mainly in the production of glass. Potassium carbonate K 2 CO 3. The technical (trivial) name is potash. In structure, properties and use, potassium carbonate is very similar to sodium carbonate. Previously, it was obtained from plant ash, and the ash itself was used in washing. Currently, most potassium carbonate is obtained as a by-product of the production of alumina (Al 2 O 3), used to make aluminum. Due to its hygroscopicity, potash is used as a drying agent. It is also used in the production of glass, pigments, and liquid soap. In addition, potassium carbonate is a convenient reagent for obtaining other potassium compounds. |
CHEMICAL NOMENCLATURE, SYSTEMATIC NAME, TRIVIAL NAME, SPECIAL NAME.
1. Write down ten trivial names of any compounds (not in the table) from the previous chapters of the textbook, write down the formulas of these substances and give their systematic names.
2. What do the trivial names “table salt”, “soda ash”, “carbon monoxide”, “burnt magnesia” mean?
8.2. Names and formulas of simple substances
The names of most simple substances coincide with the names of the corresponding elements. Only all allotropic modifications of carbon have their own special names: diamond, graphite, carbyne and others. In addition, one of the allotropic modifications of oxygen has its own special name - ozone.
The simplest formula of a simple non-molecular substance consists only of the symbol of the corresponding element, for example: Na - sodium, Fe - iron, Si - silicon.
Allotropic modifications are designated using alphabetic indices or letters of the Greek alphabet:
C (a) – diamond; -
Sn – gray tin;
C (gr) – graphite; -
Sn – white tin.
In the molecular formulas of molecular simple substances, the index, as you know, shows the number of atoms in the molecule of the substance:
H 2 – hydrogen; O 2 – oxygen; Cl 2 – chlorine; O 3 – ozone.
In accordance with nomenclature rules, the systematic name of such a substance must contain a prefix indicating the number of atoms in the molecule:
H 2 – dihydrogen;
O 3 – trioxygen;
P 4 – tetraphosphorus;
S 8 - octasulfur, etc., but at present this rule has not yet become generally accepted.
Table 26.Numeric prefixes
Factor | Console | Factor | Console | Factor | Console |
mono | penta | nona | |||
di | hexa | soundboard | |||
three | hepta | Undeka | |||
tetra | Octa | dodeca |
Ozone O3– a light blue gas with a characteristic odor, in a liquid state it is dark blue, in a solid state it is dark purple. This is the second allotropic modification of oxygen. Ozone is much more soluble in water than oxygen. O 3 is unstable and even at room temperature slowly turns into oxygen. Very reactive, destroys organic substances, reacts with many metals, including gold and platinum. You can smell ozone during a thunderstorm, since in nature ozone is formed as a result of the action of lightning and ultraviolet radiation on atmospheric oxygen. Above the Earth there is an ozone layer located at an altitude of about 40 km, which traps the bulk of the ultraviolet radiation of the Sun, which is destructive for all living things. Ozone has bleaching and disinfecting properties. In some countries it is used to disinfect water. In medical institutions, ozone produced in special devices - ozonizers - is used to disinfect premises. |
8.3. Formulas and names of binary substances
In accordance with the general rule, in the formula of a binary substance, the symbol of an element with a lower electronegativity of atoms is placed in the first place, and in the second place - with a higher one, for example: NaF, BaCl 2, CO 2, OF 2 (and not FNa, Cl 2 Ba, O 2 C or F 2 O!).
Since electronegativity values for atoms of different elements are constantly being refined, two rules of thumb are usually used:
1. If a binary compound is a compound of a metal-forming element with
element forming a non-metal, then the symbol of the element forming the metal is always placed in first place (on the left).
2. If both elements included in the compound are elements that form non-metals, then their symbols are arranged in the following sequence:
B, Si, C, Sb, As, P, N, H, Te, Se, S, At, I, Br, Cl, O, F.
Note: It should be remembered that nitrogen's place in this practical series does not correspond to its electronegativity; as a general rule it should be placed between chlorine and oxygen.
Examples: Al 2 O 3, FeO, Na 3 P, PbCl 2, Cr 2 S 3, UO 2 (according to the first rule);
BF 3, CCl 4, As 2 S 3, NH 3, SO 3, I 2 O 5, OF 2 (according to the second rule).
The systematic name of a binary compound can be given in two ways. For example, CO 2 can be called carbon dioxide - you already know this name - and carbon monoxide (IV). In the second name, the Stock number (oxidation state) of carbon is indicated in parentheses. This is done in order to distinguish this compound from CO - carbon monoxide (II).
You can use either type of name, depending on which one is more convenient in this case.
Examples (more convenient names are highlighted):
MnO | manganese monoxide | manganese(II) oxide |
Mn2O3 | dimanganese trioxide | manganese oxide(III) |
MnO2 | manganese dioxide | manganese(IV) oxide |
Mn2O7 | dimanganese heptoxide | manganese oxide(VII) |
Other examples:
If the atoms of the element that comes first in the formula of a substance exhibit only one positive oxidation state, then neither numerical prefixes nor the designation of this oxidation state in the name of the substance are usually used, for example:
Na 2 O – sodium oxide; KCl – potassium chloride;
Cs 2 S – cesium sulfide; BaCl 2 – barium chloride;
BCl 3 – boron chloride; HCl – hydrogen chloride (hydrogen chloride);
Al 2 O 3 – aluminum oxide; H 2 S – hydrogen sulfide (hydrogen sulfide).
1. Make up systematic names of substances (for binary substances - in two ways):
a) O 2, FeBr 2, BF 3, CuO, HI;
b) N 2, FeCl 2, Al 2 S 3, CuI, H 2 Te;
c) I 2, PCl 5, MnBr 2, BeH 2, Cu 2 O.
2.Name each of the nitrogen oxides in two ways: N 2 O, NO, N 2 O 3, NO 2, N 2 O 4, N 2 O 5. Emphasize more user-friendly names.
3. Write down the formulas of the following substances:
a) sodium fluoride, barium sulfide, strontium hydride, lithium oxide;
b) carbon(IV) fluoride, copper(II) sulfide, phosphorus(III) oxide, phosphorus(V) oxide;
c) silicon dioxide, diiodine pentoxide, diphosphorus trioxide, carbon disulfide;
d) hydrogen selenide, hydrogen bromide, hydrogen iodide, hydrogen telluride;
e) methane, silane, ammonia, phosphine.
4. Formulate the rules for compiling formulas for binary substances according to the position of the elements that make up this substance in the system of elements.
8.4. Formulas and names of more complex substances
As you have already noticed, in the formula of a binary compound, the first place is the symbol of a cation or atom with a partial positive charge, and the second is the symbol of an anion or an atom with a partial negative charge. Formulas for more complex substances are compiled in the same way, but the places of atoms or simple ions in them are taken by groups of atoms or complex ions.
As an example, consider the compound (NH 4) 2 CO 3. In it, the formula of a complex cation (NH 4) is in first place, and the formula of a complex anion (CO 3 2) is in second place.
In the formula of the most complex ion, the symbol of the central atom, that is, the atom to which the remaining atoms (or groups of atoms) of this ion are associated, is placed first, and the oxidation state of the central atom is indicated in the name.
Examples of systematic names:
Na 2 SO 4 sodium tetraoxosulfate(VI),
K 2 SO 3 potassium(II) trioxosulfate(IV),
CaCO 3 calcium(II) trioxocarbonate(IV),
(NH 4) 3 PO 4 ammonium tetraoxophosphate(V),
PH 4 Cl phosphonium chloride,
Mg(OH) 2 magnesium(II) hydroxide.
Such names accurately reflect the composition of the compound, but are very cumbersome. Therefore, abbreviated ones ( semi-systematic) names of these compounds:
Na 2 SO 4 sodium sulfate,
K 2 SO 3 potassium sulfite,
CaCO 3 calcium carbonate,
(NH 4) 3 PO 4 ammonium phosphate,
Mg(OH) 2 magnesium hydroxide.
The systematic names of acids are composed as if the acid is a hydrogen salt:
H 2 SO 4 hydrogen tetraoxosulfate(VI),
H 2 CO 3 hydrogen trioxocarbonate (IV),
H 2 hydrogen hexafluorosilicate (IV). (You will learn about the reasons for using square brackets in the formula of this compound later)
But for the most well-known acids, nomenclature rules allow the use of their trivial names, which, together with the names of the corresponding anions, are given in Table 27.
Table 27.Names of some acids and their anions
Name |
Formula
SEMI-SYSTEMATIC NAMES OF ACIDS AND SALTS. |
Chemical formula is an image using symbols.
Chemical element signs
Chemical sign or chemical element symbol– this is the first or two first letters of the Latin name of this element.
For example: FerrumFe , Cuprum –Cu , OxygeniumO etc.
Table 1: Information provided by a chemical sign
Intelligence | Using the example of Cl |
Item name | Chlorine |
Non-metal, halogen | |
One element | 1 chlorine atom |
(Ar) of this element | Ar(Cl) = 35.5 |
Absolute atomic mass of a chemical element
m = Ar 1.66 10 -24 g = Ar 1.66 10 -27 kg |
M (Cl) = 35.5 1.66 10 -24 = 58.9 10 -24 g |
The name of a chemical symbol in most cases is read as the name of a chemical element. For example, K – potassium, Ca – calcium, Mg – magnesium, Mn – manganese.
Cases when the name of a chemical symbol is read differently are given in Table 2:
Chemical element name | Chemical sign | Chemical symbol name
(pronunciation) |
Nitrogen | N | En |
Hydrogen | H | Ash |
Iron | Fe | Ferrum |
Gold | Au | Aurum |
Oxygen | O | ABOUT |
Silicon | Si | Silicium |
Copper | Cu | Cuprum |
Tin | Sn | Stanum |
Mercury | Hg | Hydrargium |
Lead | Pb | Plumbum |
Sulfur | S | Es |
Silver | Ag | Argentum |
Carbon | C | Tse |
Phosphorus | P | Pe |
Chemical formulas of simple substances
The chemical formulas of most simple substances (all metals and many non-metals) are the signs of the corresponding chemical elements.
So iron substance And chemical element iron are designated the same - Fe .
If it has a molecular structure (exists in the form , then its formula is the chemical sign of the element with index bottom right indicating number of atoms in a molecule: H 2, O2, O 3, N 2, F 2, Cl2, BR 2, P 4, S 8.
Table 3: Information provided by a chemical sign
Intelligence | Using C as an example |
Substance name | Carbon (diamond, graphite, graphene, carbyne) |
Belonging of an element to a given class of chemical elements | Non-metal |
One atom of an element | 1 carbon atom |
Relative atomic mass (Ar) element that forms a substance | Ar(C) = 12 |
Absolute atomic mass | M(C) = 12 1.66 10-24 = 19.93 10 -24 g |
One substance | 1 mole of carbon, i.e. 6.02 10 23 carbon atoms |
M (C) = Ar (C) = 12 g/mol |
Chemical formulas of complex substances
The formula of a complex substance is prepared by writing down the signs of the chemical elements of which the substance is composed, indicating the number of atoms of each element in the molecule. In this case, as a rule, chemical elements are written in order of increasing electronegativity in accordance with the following practical series:
Me, Si, B, Te, H, P, As, I, Se, C, S, Br, Cl, N, O, F
For example, H2O , CaSO4 , Al2O3 , CS 2 , OF 2 , NaH.
The exceptions are:
- some compounds of nitrogen with hydrogen (for example, ammonia NH 3 , hydrazine N 2H 4 );
- salts of organic acids (for example, sodium formate HCOONa , calcium acetate (CH 3COO) 2Ca) ;
- hydrocarbons ( CH 4 , C2H4 , C2H2 ).
Chemical formulas of substances existing in the form dimers (NO 2 , P2O 3 , P2O5, salts of monovalent mercury, for example: HgCl , HgNO3 etc.), written in the form N 2 O4,P 4 O6,P 4 O 10Hg 2 Cl2,Hg 2 ( NO 3) 2 .
The number of atoms of a chemical element in a molecule and a complex ion is determined based on the concept valency or oxidation states and is recorded index lower right from the sign of each element (index 1 is omitted). In this case, they proceed from the rule:
the algebraic sum of the oxidation states of all atoms in a molecule must be equal to zero (the molecules are electrically neutral), and in a complex ion - the charge of the ion.
For example:
2Al 3 + +3SO 4 2- =Al 2 (SO 4) 3
The same rule is used when determining the oxidation state of a chemical element using the formula of a substance or complex. It is usually an element that has several oxidation states. The oxidation states of the remaining elements forming the molecule or ion must be known.
The charge of a complex ion is the algebraic sum of the oxidation states of all the atoms that form the ion. Therefore, when determining the oxidation state of a chemical element in a complex ion, the ion itself is placed in brackets, and its charge is taken out of brackets.
When compiling formulas for valency a substance is represented as a compound consisting of two particles of different types, the valencies of which are known. Next they use rule:
in a molecule, the product of valence by the number of particles of one type must be equal to the product of valence by the number of particles of another type.
For example:
The number before the formula in a reaction equation is called coefficient. She indicates either number of molecules, or number of moles of substance.
The coefficient before the chemical symbol, indicates number of atoms of a given chemical element, and in the case when the sign is the formula of a simple substance, the coefficient indicates either number of atoms, or the number of moles of this substance.
For example:
- 3 Fe– three iron atoms, 3 moles of iron atoms,
- 2 H– two hydrogen atoms, 2 moles of hydrogen atoms,
- H 2– one molecule of hydrogen, 1 mole of hydrogen.
The chemical formulas of many substances have been determined experimentally, which is why they are called "empirical".
Table 4: Information provided by the chemical formula of a complex substance
Intelligence | For example C aCO3 |
Substance name | Calcium carbonate |
Belonging of an element to a certain class of substances | Medium (normal) salt |
One molecule of substance | 1 molecule calcium carbonate |
One mole of substance | 6.02 10 23 molecules CaCO3 |
Relative molecular mass of the substance (Mr) | Мr (CaCO3) = Ar (Ca) +Ar (C) +3Ar (O) =100 |
Molar mass of the substance (M) | M (CaCO3) = 100 g/mol |
Absolute molecular mass of the substance (m) | M (CaCO3) = Mr (CaCO3) 1.66 10 -24 g = 1.66 10 -22 g |
Qualitative composition (what chemical elements form the substance) | calcium, carbon, oxygen |
Quantitative composition of the substance: | |
The number of atoms of each element in one molecule of a substance: | a calcium carbonate molecule is made up of 1 atom calcium, 1 atom carbon and 3 atoms oxygen. |
The number of moles of each element in 1 mole of the substance: | In 1 mole CaCO 3(6.02 · 10 23 molecules) contained 1 mole(6.02 · 10 23 atoms) calcium, 1 mole(6.02 10 23 atoms) of carbon and 3 mol(3 6.02 10 23 atoms) of the chemical element oxygen) |
Mass composition of the substance: | |
Mass of each element in 1 mole of substance: | 1 mole of calcium carbonate (100g) contains the following chemical elements: 40g calcium, 12g carbon, 48g oxygen. |
Mass fractions of chemical elements in the substance (composition of the substance as a percentage by weight):
|
Composition of calcium carbonate by weight:
W (Ca) = (n (Ca) Ar (Ca))/Mr (CaCO3) = (1·40)/100= 0.4 (40%) W (C) = (n (Ca) Ar (Ca))/Mr (CaCO3) = (1 12)/100 = 0.12 (12%) W (O) = (n (Ca) Ar (Ca))/Mr (CaCO3) = (3 16)/100 = 0.48 (48%) |
For a substance with an ionic structure (salt, acid, base), the formula of the substance provides information about the number of ions of each type in the molecule, their quantity and the mass of ions per 1 mole of the substance:
|
Molecule CaCO 3 consists of an ion Ca 2+ and ion CO 3 2-
1 mol ( 6.02 10 23 molecules) CaCO 3 contains 1 mol Ca 2+ ions And 1 mole ions CO 3 2-; 1 mole (100g) of calcium carbonate contains 40g ions Ca 2+ And 60g ions CO 3 2- |
Molar volume of a substance at standard conditions (for gases only) |
Graphic formulas
To obtain more complete information about a substance, use graphic formulas , which indicate order of connection of atoms in a molecule And valence of each element.
Graphic formulas of substances consisting of molecules sometimes, to one degree or another, reflect the structure (structure) of these molecules; in these cases they can be called structural .
To compile a graphical (structural) formula of a substance, you must:
- Determine the valence of all chemical elements that form the substance.
- Write down the signs of all chemical elements that form the substance, each in an amount equal to the number of atoms of a given element in the molecule.
- Connect the signs of chemical elements with dashes. Each dash denotes a pair that communicates between chemical elements and therefore belongs equally to both elements.
- The number of lines surrounding the sign of a chemical element must correspond to the valence of this chemical element.
- When formulating oxygen-containing acids and their salts, hydrogen atoms and metal atoms are bonded to the acid-forming element through an oxygen atom.
- Oxygen atoms are combined with each other only when formulating peroxides.
Examples of graphic formulas:
The classification of inorganic substances and their nomenclature are based on the simplest and most constant characteristic over time -chemical composition, which shows the atoms of the elements that form a given substance in their numerical ratio. If a substance is made up of atoms of one chemical element, i.e. is the form of existence of this element in free form, then it is called simple substance ; if the substance is made up of atoms of two or more elements, then it is calledcomplex substance. All simple substances (except monatomic ones) and all complex substances are usually calledchemical compounds, since in them atoms of one or different elements are connected to each other by chemical bonds.
The nomenclature of inorganic substances consists of formulas and names.Chemical formula- depiction of the composition of a substance using symbols of chemical elements, numerical indices and some other signs.Chemical name- image of the composition of a substance using a word or group of words. The construction of chemical formulas and names is determined by the systemnomenclature rules.
The symbols and names of chemical elements are given in the Periodic Table of Elements by D.I. Mendeleev. The elements are conventionally divided into metals and non-metals . Non-metals include all elements of group VIIIA (noble gases) and group VIIA (halogens), elements of group VIA (except polonium), elements nitrogen, phosphorus, arsenic (VA group); carbon, silicon (IVA group); boron (IIIA group), as well as hydrogen. The remaining elements are classified as metals.
When compiling the names of substances, Russian names of elements are usually used, for example, dioxygen, xenon difluoride, potassium selenate. Traditionally, for some elements, the roots of their Latin names are introduced into derivative terms:
The following are usednumerical prefixes:
1 - mono | 7 - hepta |
2 - di |
3 - three | 9 - nona |
4 - tetra |
5 - penta |
6 - hex |
An indefinite number is indicated by a numeric prefix n - poly.
For some simple substances they also use special names such as O 3 - ozone, P 4 - white phosphorus.
Chemical formulas complex substances made up of the designationelectropositive(conditional and real cations) andelectronegative(conditional and real anions) components, for example, CuSO 4 (here Cu 2+ - real cation, SO 4
2-
- real anion) and PCl 3 (here P +III - conditional cation, Cl-I - conditional anion).
Names of complex substances composed according to chemical formulas from right to left. They are made up of two words - the names of electronegative components (in the nominative case) and electropositive components (in the genitive case), for example:
CuSO4 - copper(II) sulfate
PCl 3
- phosphorus trichloride
LaCl 3
- lanthanum(III) chloride
CO - carbon monoxide
The number of electropositive and electronegative components in the names is indicated by the numerical prefixes given above (universal method), or by oxidation states (if they can be determined by the formula) using Roman numerals in parentheses (the plus sign is omitted). In some cases, the charge of ions is given (for cations and anions of complex composition), using Arabic numerals with the appropriate sign.
The following special names are used for common multielement cations and anions:
NH 4 + - ammonium | HF 2 - - hydrodifluoride |
For a small number of well-known substances it is also used special names:
AsH 3 - arsine | HN 3 - hydrogen azide |
B 2 H 6 - borane | H 2 S - hydrogen sulfide |
1. Acidic and basic hydroxides. Salts
Hydroxides are a type of complex substances that contain atoms of some element E (except fluorine and oxygen) and hydroxyl groups OH; general formula of hydroxides E(OH) n, where n = 1÷6. Form of hydroxides E(OH) n is called ortho -form; at n > 2 hydroxide can also be found in meta -form, which includes, in addition to E atoms and OH groups, oxygen atoms O, for example E(OH) 3 and EO(OH), E(OH) 4 and E(OH) 6 and EO 2 (OH) 2.
Hydroxides are divided into two groups with opposite chemical properties: acidic and basic hydroxides.
Acidic hydroxidescontain hydrogen atoms, which can be replaced by metal atoms subject to the rule of stoichiometric valency. Most acid hydroxides are found in meta -form, and hydrogen atoms in the formulas of acidic hydroxides are placed in first place, for example H 2 SO 4, HNO 3 and H 2 CO 3, not SO 2 (OH) 2, NO 2 (OH) and CO (OH) 2 . The general formula of acid hydroxides is H x EO y , where the electronegative component EO y x- called an acid residue. If not all hydrogen atoms are replaced by a metal, then they remain as part of the acid residue.
The names of common acid hydroxides consist of two words: the proper name with the ending “aya” and the group word “acid”. Here are the formulas and proper names of common acid hydroxides and their acidic residues (a dash means that the hydroxide is not known in free form or in an acidic aqueous solution):
HAsO2 - metaarsenic | AsO 2 - - metaarsenite |
H3AsO3 - orthoarsenic | AsO 3 3- - orthoarsenite |
H 3 AsO 4 - arsenic | AsO 4 3- - arsenate |
-
| B 4 O 7 2- - tetraborate |
-
| ВiО 3 - - bismuthate |
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 | IO 3 - - iodate |
HIO 4 - metaiodine | IO 4 - - metaperiodate |
H 5 IO 6 - orthoiodine | IO 6 5- - orthoperiodate |
HMnO 4 - manganese | MnO 4 - - permanganate |
HNO 2 - nitrogenous | NO 2 - - nitrite |
HNO 3 - nitrogen | NO 3 - - nitrate |
HPO 3 - metaphosphoric | PO 3 - - metaphosphate |
H3PO4 - orthophosphoric | PO 4 3- - orthophosphate |
| НPO 4 2- - hydroorthophosphate |
| H 2 PO 4 - - dihydroothophosphate |
H 4 P 2 O 7 - diphosphoric | P 2 O 7 4- - diphosphate |
Less common acid hydroxides are named according to nomenclature rules for complex compounds, for example:
The names of acid residues are used to construct the names of salts.
Basic hydroxidescontain hydroxide ions, which can be replaced by acid residues subject to the rule of stoichiometric valency. All basic hydroxides are found in ortho -shape; their general formula is M(OH) n, where n = 1.2 (less often 3.4) and M n +- metal cation. Examples of formulas and names of basic hydroxides:
The most important chemical property of basic and acidic hydroxides is their interaction with each other to form salts (salt formation reaction), For example:
Ca(OH) 2 + H 2 SO 4 = CaSO 4 + 2H 2 O
Ca(OH) 2 + 2H 2 SO 4 = Ca(HSO 4 ) 2 + 2H 2 O
2Ca(OH)2 + H2SO4 = Ca2SO4(OH)2 + 2H2O
Salts are a type of complex substances that contain M cations n+ and acid residues*.
Salts with general formula M x (EO y) n are called average salts, and salts with unsubstituted hydrogen atoms - sour salts. Sometimes salts also contain hydroxide and/or oxide ions; such salts are called main salts. Here are examples and names of salts:
CuCO3 | Copper(II) carbonate |
Ti(NO3)2O | Titanium oxide dinitrate |
Acid and basic salts can be converted to middle salts by reaction with the appropriate basic and acidic hydroxide, for example:
Ca(HSO 4 ) 2 + Ca(OH) = CaSO 4
+ 2H2
O
Ca2
SO4
(OH)2
+H2
SO4
=Ca2
SO4
+ 2H2
O
There are also salts containing two different cations: they are often calleddouble salts, For example:
2. Acidic and basic oxides
Oxides EXABOUTat- products of complete dehydration of hydroxides:
Acid hydroxides (H2
SO4
,
H2
CO3
)
acid oxides answer(SO3
, CO2
), and basic hydroxides (NaOH, Ca(OH)2
) -
basic oxides(Na2
O, CaO), and the oxidation state of element E does not change when moving from hydroxide to oxide. Example of formulas and names of oxides:
SO3
- sulfur trioxide | Na2
O - sodium oxide |
P4
O10
- tetraphosphorus decaoxide | ThO2
- thorium(IV) oxide |
Acidic and basic oxides retain the salt-forming properties of the corresponding hydroxides when interacting with hydroxides of opposite properties or with each other:
N2
O5
+ 2NaOH = 2NaNO3
+H2
O
3CaO + 2H3
P.O.4
=Ca3
(P.O.4
)
2
+ 3H2
O
La2
O3
+3SO3
=La2
(SO4
)
3
3.
Amphoteric oxides and hydroxides
Amphotericityhydroxides and oxides - a chemical property consisting in the formation of two rows of salts by them, for example, for aluminum hydroxide and aluminum oxide:
(a) 2Al(OH)3
+3SO3
= Al2
(SO4
)
3
+ 3H2
O
Al2
O3
+ 3H2
SO4
= Al2
(SO4
)
3
+ 3H2
O
(b) 2Al(OH)3
+Na2
O = 2NaAlO2
+ 3H2
O
Al2
O3
+ 2NaOH = 2NaAlO2
+H2
O
Thus, aluminum hydroxide and oxide in reactions (a) exhibit the propertiesmainhydroxides and oxides, i.e. react with acidic hydroxides and oxide, forming the corresponding salt - aluminum sulfate Al2
(SO4
)
3
, whereas in reactions (b) they also exhibit propertiesacidichydroxides and oxides, i.e. react with basic hydroxide and oxide, forming a salt - sodium dioxoaluminate (III) NaAlO2
. In the first case, the element aluminum exhibits the properties of a metal and is part of the electropositive component (Al3+
), in the second - the property of a non-metal and is part of the electronegative component of the salt formula (AlO2
-
).
If these reactions occur in an aqueous solution, then the composition of the resulting salts changes, but the presence of aluminum in the cation and anion remains:
2Al(OH)3
+ 3H2
SO4
=
2
(SO4
)
3
Al(OH)3
+ NaOH = Na
Here complex ions are highlighted in square brackets3+
- hexaaqua aluminum(III) cation,-
- tetrahydroxoaluminate(III) ion.
Elements that exhibit metallic and non-metallic properties in compounds are called amphoteric, these include elements of the A-groups of the Periodic Table - Be, Al, Ga, Ge, Sn, Pb, Sb, Bi, Po, etc., as well as most elements of the B- groups - Cr, Mn, Fe, Zn, Cd, Au, etc. Amphoteric oxides are called the same as basic ones, for example:
If an amphoteric element in a compound has several oxidation states, then the amphotericity of the corresponding oxides and hydroxides (and, consequently, the amphotericity of the element itself) will be expressed differently. For low oxidation states, hydroxides and oxides have a predominance of basic properties, and the element itself has metallic properties, so it is almost always included in the composition of cations. For high oxidation states, on the contrary, hydroxides and oxides have a predominance of acidic properties, and the element itself has non-metallic properties, so it is almost always included in the composition of anions. Thus, manganese(II) oxide and hydroxide have dominant basic properties, and manganese itself is part of cations of the type2+
, while manganese(VII) oxide and hydroxide have dominant acidic properties, and manganese itself is part of the MnO type anion4
-
. Amphoteric hydroxides with a high predominance of acidic properties are assigned formulas and names modeled after acidic hydroxides, for example HMnVIIO4
- permanganic acid.
Thus, the division of elements into metals and non-metals is conditional; Between the elements (Na, K, Ca, Ba, etc.) with purely metallic properties and the elements (F, O, N, Cl, S, C, etc.) with purely non-metallic properties, there is a large group of elements with amphoteric properties.
4. Binary compounds
A broad type of inorganic complex substances are binary compounds. These include, first of all, all two-element compounds (except basic, acidic and amphoteric oxides), for example H2
O, KBr, H2
S, Cs2
(S2
), N2
O,NH3
,HN3
,CaC2
, SiH4
. The electropositive and electronegative components of the formulas of these compounds include individual atoms or bonded groups of atoms of the same element.
Multielement substances, in the formulas of which one of the components contains unrelated atoms of several elements, as well as single-element or multi-element groups of atoms (except hydroxides and salts), are considered as binary compounds, for example CSO, IO2 F3 , SBrO2 F, CrO(O2 ) 2 , PSI3 , (CaTi)O3 , (FeCu)S2
Pb(N3
)
2
- lead(II) azide
For some binary compounds, special names are used, a list of which was given earlier.
The chemical properties of binary compounds are quite diverse, so they are often divided into groups by the name of anions, i.e. halides, chalcogenides, nitrides, carbides, hydrides, etc. are considered separately. Among the binary compounds there are also those that have some characteristics of other types of inorganic substances. Thus, compounds CO, NO, NO2
, and (FeIIFe2
III)O4
oxides whose names are constructed using the word oxide cannot be classified as oxides (acidic, basic, amphoteric). Carbon monoxide CO, nitrogen monoxide NO and nitrogen dioxide NO2
do not have corresponding acid hydroxides (although these oxides are formed by non-metals C and N), and they do not form salts whose anions would include C atomsII, NIIand NIV. Double oxide (FeIIFe2
III)O4
- diiron(III)-iron(II) oxide, although it contains atoms of the amphoteric element - iron in the electropositive component, but in two different oxidation states, as a result of which, when interacting with acidic hydroxides, it forms not one, but two different salts.
Binary compounds such as AgF, KBr, Na2 S, Ba(HS)2 ,NaCN,NH4 Cl, and Pb(N3 ) 2 , are built, like salts, from real cations and anions, which is why they are calledsalt-likebinary compounds (or simply salts). They can be considered as products of the replacement of hydrogen atoms in the compounds HF, HCl, HBr, H2 S, НCN and НN3 . The latter in an aqueous solution have an acidic function, and therefore their solutions are called acids, for example HF (aqua) - hydrofluoric acid, H2 S(aqua) - hydrosulfide acid. However, they do not belong to the type of acid hydroxides, and their derivatives do not belong to the salts within the classification of inorganic substances.
TRIVIAL NAMES OF SUBSTANCES. For many centuries and millennia, people have used a wide variety of substances in their practical activities. Quite a few of them are mentioned in the Bible (these include precious stones, dyes, and various incense). Of course, each of them was given a name. Of course, it had nothing to do with the composition of the substance. Sometimes the name reflected an appearance or a special property, real or fictitious. A typical example is a diamond. In Greek damasma - subjugation, taming, damao - crushing; accordingly, adamas means indestructible (it’s interesting that in Arabic “al-mas” means the hardest, the hardest). In ancient times, miraculous properties were attributed to this stone, for example, this: if you put a diamond crystal between a hammer and an anvil, they would sooner shatter into pieces than the “king of stones” would be damaged. In fact, diamond is very fragile and cannot withstand impacts at all. But the word “diamond” actually reflects the property of a cut diamond: in French brilliant means brilliant.
Alchemists came up with many names for substances. Some of them have survived to this day. Thus, the name of the element zinc (it was introduced into the Russian language by M.V. Lomonosov) probably comes from the ancient German tinka - “white”; Indeed, the most common zinc preparation, ZnO oxide, is white. At the same time, alchemists came up with many of the most fantastic names - partly due to their philosophical views, partly - to classify the results of their experiments. For example, they called the same zinc oxide “philosophical wool” (alchemists obtained this substance in the form of a loose powder). Other names were based on how the substance was obtained. For example, methyl alcohol was called wood alcohol, and calcium acetate was called “burnt wood salt” (to obtain both substances, dry distillation of wood was used, which, of course, led to its charring - “burning”). Very often the same substance received several names. For example, even by the end of the 18th century. there were four names for copper sulfate, ten for copper carbonate, and twelve for carbon dioxide!
The description of chemical procedures was also ambiguous. Thus, in the works of M.V. Lomonosov one can find references to “dissolved scum,” which may confuse the modern reader (although cookbooks sometimes contain recipes that require “dissolving a kilogram of sugar in a liter of water,” and “scum” simply means "sediment")
Currently, the names of substances are regulated by the rules of chemical nomenclature (from the Latin nomenclatura - list of names). In chemistry, nomenclature is a system of rules, using which you can give each substance a “name” and, conversely, knowing the “name” of the substance, write down its chemical formula. Developing a unified, unambiguous, simple and convenient nomenclature is not an easy task: suffice it to say that even today there is no complete unity among chemists on this matter. Issues of nomenclature are dealt with by a special commission of the International Union of Pure and Applied Chemistry - IUPAC (according to the initial letters of the English name International Union of Pure and Applied Chemistry). And national commissions develop rules for applying IUPAC recommendations to the language of their country. Thus, in the Russian language, the ancient term “oxide” was replaced by the international “oxide”, which was also reflected in school textbooks.
Anecdotal stories are also associated with the development of a system of national names for chemical compounds. For example, in 1870, the commission on chemical nomenclature of the Russian Physicochemical Society discussed the proposal of one chemist to name compounds according to the same principle by which first names, patronymics and surnames are built in the Russian language. For example: Potassium Khlorovich (KCl), Potassium Khlorovich Trikislov (KClO 3), Chlorine Vodorodovich (HCl), Hydrogen Kislorodovich (H 2 O). After a long debate, the commission decided to postpone discussion of this issue until January, without specifying what year. Since then, the commission has not returned to this issue.
Modern chemical nomenclature is more than two centuries old. In 1787, the famous French chemist Antoine Laurent Lavoisier presented the results of the work of the commission he headed to create a new chemical nomenclature to the Academy of Sciences in Paris. In accordance with the proposals of the commission, new names were given to chemical elements, as well as complex substances, taking into account their composition. The names of the elements were selected so that they reflected the characteristics of their chemical properties. Thus, the element that Priestley previously called “dephlogisticated air”, Scheele - “fiery air”, and Lavoisier himself - “vital air”, according to the new nomenclature, received the name oxygen (at that time it was believed that acids necessarily included this element). Acids are named after their corresponding elements; as a result, “nitrate fumed acid” turned into nitric acid, and “oil of vitriol” into sulfuric acid. To designate salts, the names of acids and corresponding metals (or ammonium) began to be used.
The adoption of a new chemical nomenclature made it possible to systematize extensive factual material and greatly facilitated the study of chemistry. Despite all the changes, the basic principles laid down by Lavoisier have been preserved to this day. Nevertheless, among chemists, and especially among laymen, many so-called trivial (from Latin trivialis - ordinary) names have been preserved, which are sometimes used incorrectly. For example, a person who feels unwell is offered to “smell ammonia.” For a chemist, this is nonsense, since ammonia (ammonium chloride) is an odorless salt. In this case, ammonia is confused with ammonia, which really has a pungent odor and stimulates the respiratory center.
A lot of trivial names for chemical compounds are still used by artists, technologists, and builders (ochre, mummy, red lead, cinnabar, litharge, fluff, etc.). Even more trivial names among medicines. In reference books you can find up to a dozen or more different synonyms for the same drug, which is mainly due to brand names adopted in different countries (for example, domestic piracetam and imported nootropil, Hungarian Seduxen and Polish Relanium, etc.).
Chemists also often use trivial names for substances, sometimes quite interesting ones. For example, 1,2,4,5-tetramethylbenzene has the trivial name "durol", and 1,2,3,5-tetramethylbenzene - "isodurol". A trivial name is much more convenient if it is obvious to everyone what we are talking about. For example, even a chemist will never call ordinary sugar “alpha-D-glucopyranosyl-beta-D-fructofuranoside”, but uses the trivial name for this substance - sucrose. And even in inorganic chemistry, the systematic, strictly nomenclature, name of many compounds can be cumbersome and inconvenient, for example: O 2 - dioxygen, O 3 - trioxygen, P 4 O 10 - tetraphosphorus decaoxide, H 3 PO 4 - hydrogen tetraoxophosphate (V) , BaSO 3 – barium trioxosulfate, Cs 2 Fe(SO 4) 2 – iron(II)-dicesium tetraoxosulfate(VI), etc. And although the systematic name fully reflects the composition of the substance, in practice trivial names are used: ozone, phosphoric acid, etc.
Among chemists, the names of many compounds are also common, especially complex salts, such as Zeise's salt K.H 2 O - named after the Danish chemist William Zeise. Such short names are very convenient. For example, instead of “potassium nitrodisulfonate” the chemist will say “Fremy’s salt”, instead of “crystalline hydrate of double ammonium iron(II) sulfate” - Mohr’s salt, etc.
The table shows the most common trivial (everyday) names of some chemical compounds, with the exception of highly specialized, outdated, medical terms, and names of minerals, as well as their traditional chemical names.
Table 1. TRIVIAL (HOUSEHOLD) NAMES OF SOME CHEMICAL COMPOUNDS | ||
Trivial name | Chemical name | Formula |
Alabaster | Calcium sulfate hydrate (2/1) | 2CaSO4 . H2O |
Anhydrite | Calcium sulfate | CaSO4 |
Orpiment | Arsenic sulfide | As 2 S 3 |
White lead | Basic lead carbonate | 2PbCO3 . Pb(OH)2 |
Titanium white | Titanium(IV) oxide | TiO2 |
Zinc whitewash | Zinc oxide | ZnO |
Prussian blue | Iron(III)-potassium hexacyanoferrate(II) | KFe |
Bertholet's salt | Potassium chlorate | KClO3 |
Marsh gas | Methane | CH 4 |
Borax | Sodium tetraborate tetrahydrate | Na2B4O7 . 10H2O |
Laughing gas | Nitric oxide(I) | N2O |
Hyposulfite (photo) | Sodium thiosulfate pentahydrate | Na2S2O3 . 5H 2 O |
Glauber's salt | Sodium sulfate decahydrate | Na2SO4 . 10H2O |
Lead litharge | Lead(II) oxide | PbO |
Alumina | Aluminium oxide | Al2O3 |
Epsom salt | Magnesium sulfate heptahydrate | MgSO4 . 7H2O |
Caustic soda (caustic) | Sodium hydroxide | NaOH |
Caustic potassium | Potassium hydroxide | CON |
Yellow blood salt | Potassium hexacyanoferrate(III) trihydrate | K4Fe(CN)6 . 3H2O |
Cadmium yellow | Cadmium sulfide | CdS |
Magnesia | Magnesium oxide | MgO |
Slaked lime (fluff) | Calcium hydroxide | Ca(OH) 2 |
Burnt lime (quicklime, boiling water) | Calcium oxide | Sao |
Calomel | Mercury(I) chloride | Hg2Cl2 |
Carborundum | Silicon carbide | SiC |
Alum | Dodecahydrates of double sulfates of 3- and 1-valent metals or ammonium (for example, potassium alum) | M I M III (SO 4) 2 . 12H 2 O (M I – Na, K, Rb, Cs, Tl, NH 4 cations; M III – Al, Ga, In, Tl, Ti, V, Cr, Fe, Co, Mn, Rh, Ir cations) |
Cinnabar | Mercury sulfide | HgS |
Red blood salt | Potassium hexacyanoferrate(II) | K 3 Fe(CN) 6 |
Silica | Silicon oxide | SiO2 |
Vitriol oil (battery acid) | Sulfuric acid | H 2 SO4 |
Vitriol | Crystal hydrates of sulfates of a number of divalent metals | M II SO 4 . 7H 2 O (M II – Fe, Co, Ni, Zn, Mn cations) |
Lapis | Silver nitrate | AgNO3 |
Urea | Urea | CO(NH 2) 2 |
Ammonia | Aqueous ammonia solution | NH 3 . x H2O |
Ammonia | Ammonium chloride | NH4Cl |
Oleum | A solution of sulfur(III) oxide in sulfuric acid | H2SO4 . x SO 3 |
Perhydrol | 30% aqueous hydrogen peroxide solution | H 2 O 2 |
Hydrofluoric acid | Aqueous hydrogen fluoride solution | HF |
Table (rock) salt | Sodium chloride | NaCl |
Potash | Potassium carbonate | K 2 CO 3 |
Soluble glass | Sodium silicate nonahydrate | Na 2 SiO 3 . 9H2O |
Lead sugar | Lead acetate trihydrate | Pb(CH3COO)2 . 3H2O |
Seignet salt | Potassium sodium tartrate tetrahydrate | KNaC4H4O6 . 4H2O |
Ammonium nitrate | Ammonium nitrate | NH4NO3 |
Potassium nitrate (Indian) | Potassium nitrate | KNO 3 |
Norwegian saltpeter | Calcium nitrate | Ca(NO3)2 |
Chilean saltpeter | Sodium nitrate | NaNO3 |
Sulfur liver | Sodium polysulfides | Na2S x |
Sulphur dioxide | Sulfur(IV) oxide | SO 2 |
Sulfuric anhydride | Sulfur(VI) oxide | SO 3 |
Sulfur color | Fine sulfur powder | S |
Silica gel | Dried silicic acid gel | SiO2 . x H2O |
Hydrocyanic acid | Hydrogen cyanide | HCN |
Soda ash | Sodium carbonate | Na 2 CO 3 |
Caustic soda (see Caustic soda) | ||
Drinking soda | Sodium bicarbonate | NaHCO3 |
Foil | Tin foil | Sn |
Corrosive sublimate | Mercury(II) chloride | HgCl2 |
Double superphosphate | Calcium Dihydrogen Phosphate Hydrate | Ca(H 2 PO 4) 2 . H 2 O |
Simple superphosphate | The same mixed with CaSO 4 | |
Gold leaf | Tin(IV) sulfide or gold foil | SnS2, Au |
Lead minium | Lead(IV) oxide - dislead(II) | Pb 3 O 4 (Pb 2 II Pb IV O 4) |
Iron minium | Diiron(III)-iron(II) oxide | Fe 3 O 4 (Fe II Fe 2 III) O 4 |
Dry ice | Solid carbon monoxide(IV) | CO2 |
Bleaching powder | Mixed chloride-calcium hypochlorite | Ca(OCl)Cl |
Carbon monoxide | Carbon(II) monoxide | CO |
Carbon dioxide | Carbon monoxide | CO 2 |
Phosgene | Carbonyl dichloride | COCl2 |
Chrome green | Chromium(III) oxide | Cr2O3 |
Chrompic (potassium) | Potassium dichromate | K2Cr2O7 |
verdigris | Basic copper acetate | Cu(OH)2 . x Cu(CH3COO)2 |
Ilya Leenson