Cheat sheet - chemical names and formulas of substances. Chemical formulas of substances So4 2 name of substance

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 notationelectropositive(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 corresponding 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.

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 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.

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 called complex substance. All simple substances (except monatomic ones) and all complex substances are usually called chemical 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 system nomenclature 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 nonmetals . 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.

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

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

The following are used numerical prefixes:

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 notation electropositive(conditional and real cations) and electronegative(conditional and real anions) components, for example, CuSO 4 (here Cu 2+ is a real cation, SO 4 2 - is a real anion) and PCl 3 (here P +III is a conditional cation, Cl -I is a conditional anion).

Titles 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:

CuSO 4 - copper(II) sulfate
PCl 3 - phosphorus trichloride
LaCl 3 - lanthanum(III) chloride
CO - carbon monoxide

The following special names are used for common multielement cations and anions:

H 2 F + - fluoronium	C 2 2 - - acetylenide
H 3 O + - oxonium	CN - - cyanide
H 3 S + - sulfonium	CNO - - fulminate
NH 4 + - ammonium	HF 2 - - hydrodifluoride
N 2 H 5 + - hydrazinium(1+)	HO 2 - - hydroperoxide
N 2 H 6 + - hydrazinium(2+)	HS - - hydrosulfide
NH 3 OH + - hydroxylamine	N 3 - - azide
NO+ - nitrosyl	NCS - - thiocyanate
NO 2 + - nitroyl	O 2 2 - - peroxide
O 2 + - dioxygenyl	O 2 - - superoxide
PH 4 + - phosphonium	O 3 - - ozonide
VO 2+ - vanadyl	OCN - - cyanate
UO 2+ - uranyl	OH - - hydroxide

For a small number of well-known substances it is also used special titles:

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 called ortho-shape; 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 hydroxides contain 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 given first place, for example, H 2 SO 4, HNO 3 and H 2 CO 3, and not SO 2 (OH) 2, NO 2 (OH) and CO (OH) 2. The general formula of acid hydroxides is H X EO at, 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.

acid hydroxide	acid residue
HAsO 2 - metaarsenic	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 - bromide	BrO - - hypobromite
HBrO 3 - brominated	BrO 3 - - bromate
H 2 CO 3 - coal	CO 3 2 - - carbonate
HClO - hypochlorous	ClO- - hypochlorite
HClO 2 - chloride	ClO2 - - chlorite
HClO 3 - chloric	ClO3 - - chlorate
HClO 4 - chlorine	ClO4 - - 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	IO 3 - - iodate
HIO 4 - metaiodine	IO 4 - - metaperiodate
H 5 IO 6 - orthoiodine	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
	НPO 4 2 - - hydroorthophosphate
	H 2 PO 4 - - dihydroothophosphate
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
	HSO 4 - - hydrogen sulfate
H 2 S 2 O 7 - disulfur	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 - thiosulfur	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 - metatelluric	TeO 4 2 - - metatellurate
H 6 TeO 6 - orthotelluric	TeO 6 6 - - orthotellurate
	VO 3 - - metavanadate
	VO 4 3 - - orthovanadate
	WO 4 3 - - tungstate

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 hydroxides contain 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+ is a 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 acidic residues*.

Salts with general formula M X(EO at)n 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:

	Calcium orthophosphate
	Calcium dihydrogen orthophosphate
	Calcium hydrogen phosphate
	Copper(II) carbonate
Cu 2 CO 3 (OH) 2	Dicopper dihydroxide carbonate
	Lanthanum(III) nitrate
	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 + 2H 2 O

Ca 2 SO 4 (OH) 2 + H 2 SO 4 = Ca 2 SO 4 + 2H 2 O

There are also salts containing two different cations: they are often called double salts, For example:

2. Acidic and basic oxides

Oxides E X ABOUT at- products of complete dehydration of hydroxides:

Acid hydroxides (H 2 SO 4, H 2 CO 3) acid oxides answer(SO 3, CO 2), and basic hydroxides (NaOH, Ca(OH) 2) - basicoxides(Na 2 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:

Acidic and basic oxides retain the salt-forming properties of the corresponding hydroxides when interacting with hydroxides of opposite properties or with each other:

N 2 O 5 + 2NaOH = 2NaNO 3 + H 2 O

3CaO + 2H 3 PO 4 = Ca 3 (PO 4) 2 + 3H 2 O

La 2 O 3 + 3SO 3 = La 2 (SO 4) 3

3. Amphoteric oxides and hydroxides

Amphotericity hydroxides 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 + 3SO 3 = Al 2 (SO 4) 3 + 3H 2 O

Al 2 O 3 + 3H 2 SO 4 = Al 2 (SO 4) 3 + 3H 2 O

(b) 2Al(OH) 3 + Na 2 O = 2NaAlO 2 + 3H 2 O

Al 2 O 3 + 2NaOH = 2NaAlO 2 + H 2 O

Thus, aluminum hydroxide and oxide in reactions (a) exhibit the properties main hydroxides and oxides, i.e. react with acidic hydroxides and oxide, forming the corresponding salt - aluminum sulfate Al 2 (SO 4) 3, while in reactions (b) they also exhibit the properties acidic hydroxides and oxides, i.e. react with basic hydroxide and oxide, forming a salt - sodium dioxoaluminate (III) NaAlO 2. In the first case, the element aluminum exhibits the property of a metal and is part of the electropositive component (Al 3+), in the second - the property of a non-metal and is part of the electronegative component of the salt formula (AlO 2 -).

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 + 3H 2 SO 4 = 2 (SO 4) 3

Al(OH) 3 + NaOH = Na

Here, complex ions 3+ - hexaaqualuminium(III) cation, - - tetrahydroxoaluminate(III) ion are highlighted in square brackets.

Amphoteric hydroxides (if the oxidation state of the element exceeds + II) can be found in ortho- or (and) meta- form. Here are examples of amphoteric hydroxides:

Amphoteric oxides do not always correspond to amphoteric hydroxides, since when trying to obtain the latter, hydrated oxides are formed, 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 2+ type, while manganese(VII) oxide and hydroxide have dominant acidic properties, and manganese itself is part of the MnO 4 - type anion. . Amphoteric hydroxides with a high predominance of acidic properties are assigned formulas and names modeled after acidic hydroxides, for example HMn VII O 4 - manganese acid.

4. Binary compounds

A broad type of inorganic complex substances are binary compounds. These include, first of all, all two-element compounds (except for basic, acidic and amphoteric oxides), for example H 2 O, KBr, H 2 S, Cs 2 (S 2), N 2 O, NH 3, HN 3, CaC 2 , SiH 4 . 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, IO 2 F 3, SBrO 2 F, CrO (O 2) 2, PSI 3, (CaTi)O 3, (FeCu)S 2, Hg(CN) 2, (PF 3) 2 O, VCl 2 (NH 2). Thus, CSO can be represented as a CS 2 compound in which one sulfur atom is replaced by an oxygen atom.

The names of binary compounds are constructed according to the usual nomenclature rules, for example:

OF 2 - oxygen difluoride	K 2 O 2 - potassium peroxide
HgCl 2 - mercury(II) chloride	Na 2 S - sodium sulfide
Hg 2 Cl 2 - dimercury dichloride	Mg 3 N 2 - magnesium nitride
SBr 2 O - sulfur oxide-dibromide	NH 4 Br - ammonium bromide
N 2 O - dinitrogen oxide	Pb(N 3) 2 - lead(II) azide
NO 2 - nitrogen dioxide	CaC 2 - calcium acetylenide

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 binary compounds there are also those that have some characteristics of other types of inorganic substances. Thus, the compounds CO, NO, NO 2, and (Fe II Fe 2 III) O 4, the names of which are constructed using the word oxide, cannot be classified as oxides (acidic, basic, amphoteric). Carbon monoxide CO, nitrogen monoxide NO and nitrogen dioxide NO 2 do not have corresponding acid hydroxides (although these oxides are formed by non-metals C and N), nor do they form salts whose anions would include atoms C II, N II and N IV. Double oxide (Fe II Fe 2 III) O 4 - 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 acid hydroxides, it forms not one, but two different salts.

Binary compounds such as AgF, KBr, Na 2 S, Ba(HS) 2, NaCN, NH 4 Cl, and Pb(N 3) 2 are built, like salts, from real cations and anions, which is why they are called salt-like binary compounds (or simply salts). They can be considered as products of the substitution of hydrogen atoms in the compounds HF, HCl, HBr, H 2 S, HCN and HN 3. The latter in an aqueous solution have an acidic function, and therefore their solutions are called acids, for example HF (aqua) - hydrofluoric acid, H 2 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.

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A brief dictionary of biochemical terms, Kunizhev S.M.. The dictionary is intended for students of chemical and biological specialties at universities studying a course in general biochemistry, ecology and fundamentals of biotechnology, and can also be used in ...

Well, to complete our acquaintance with alcohols, I will also give the formula of another well-known substance - cholesterol. Not everyone knows that it is a monohydric alcohol!

|`/`\\`|<`|w>`\`/|<`/w$color(red)HO$color()>\/`|0/`|/\<`|w>|_q_q_q<-dH>:a_q|0<|dH>`/<`|wH>`\|dH; #a_(A-72)<_(A-120,d+)>-/-/<->`\

I marked the hydroxyl group in it in red.

Carboxylic acids

Any winemaker knows that wine should be stored without access to air. Otherwise it will turn sour. But chemists know the reason - if you add another oxygen atom to an alcohol, you get an acid.
Let's look at the formulas of acids that are obtained from alcohols already familiar to us:

Substance			Skeletal formula
Methane acid (formic acid)	H/C`\|O\|\OH	HCOOH	O//\OH
Ethanoic acid (acetic acid)	H-C-C\O-H; H\|#C\|H	CH3-COOH	/`\|O\|\OH
Propanic acid (methylacetic acid)	H-C-C-C\O-H; H\|#2\|H; H\|#3\|H	CH3-CH2-COOH	\/`\|O\|\OH
Butanoic acid (butyric acid)	H-C-C-C-C\O-H; H\|#2\|H; H\|#3\|H; H\|#4\|H	CH3-CH2-CH2-COOH	/\/`\|O\|\OH
Generalized formula	(R)-C\O-H	(R)-COOH or (R)-CO2H	(R)/`\|O\|\OH

A distinctive feature of organic acids is the presence of a carboxyl group (COOH), which gives such substances acidic properties.

Anyone who has tried vinegar knows that it is very sour. The reason for this is the presence of acetic acid in it. Typically table vinegar contains between 3 and 15% acetic acid, with the rest (mostly) water. Consumption of acetic acid in undiluted form poses a danger to life.

Carboxylic acids can have multiple carboxyl groups. In this case they are called: dibasic, tribasic etc...

Food products contain many other organic acids. Here are just a few of them:

The name of these acids corresponds to the food products in which they are contained. By the way, please note that here there are acids that also have a hydroxyl group, characteristic of alcohols. Such substances are called hydroxycarboxylic acids(or hydroxy acids).
Below, under each of the acids, there is a sign specifying the name of the group of organic substances to which it belongs.

Radicals

Radicals are another concept that has influenced chemical formulas. The word itself is probably known to everyone, but in chemistry radicals have nothing in common with politicians, rebels and other citizens with an active position.
Here these are just fragments of molecules. And now we will figure out what makes them special and get acquainted with a new way of writing chemical formulas.

Generalized formulas have already been mentioned several times in the text: alcohols - (R)-OH and carboxylic acids - (R)-COOH. Let me remind you that -OH and -COOH are functional groups. But R is a radical. It’s not for nothing that he is depicted as the letter R.

To be more specific, a monovalent radical is a part of a molecule lacking one hydrogen atom. Well, if you subtract two hydrogen atoms, you get a divalent radical.

Radicals in chemistry received their own names. Some of them even received Latin designations similar to the designations of the elements. And besides, sometimes in formulas radicals can be indicated in abbreviated form, more reminiscent of gross formulas.
All this is demonstrated in the following table.

Name	Structural formula	Designation	Brief formula	Example of alcohol
Methyl	CH3-()	Me	CH3	(Me)-OH	CH3OH
Ethyl	CH3-CH2-()	Et	C2H5	(Et)-OH	C2H5OH
I cut through	CH3-CH2-CH2-()	Pr	C3H7	(Pr)-OH	C3H7OH
Isopropyl	H3C\CH(`/H3C)-()	i-Pr	C3H7	(i-Pr)-OH	(CH3)2CHOH
Phenyl	`/`=`\//-\\-{}	Ph	C6H5	(Ph)-OH	C6H5OH

I think everything is clear here. I just want to draw your attention to the column where examples of alcohols are given. Some radicals are written in a form that resembles the gross formula, but the functional group is written separately. For example, CH3-CH2-OH turns into C2H5OH.
And for branched chains like isopropyl, structures with brackets are used.

There is also such a phenomenon as free radicals. These are radicals that, for some reason, have separated from functional groups. In this case, one of the rules with which we began studying the formulas is violated: the number of chemical bonds no longer corresponds to the valency of one of the atoms. Well, or we can say that one of the connections becomes open at one end. Free radicals usually live for a short time as the molecules tend to return to a stable state.

Introduction to nitrogen. Amines

I propose to get acquainted with another element that is part of many organic compounds. This nitrogen.
It is denoted by the Latin letter N and has a valency of three.

Let's see what substances are obtained if nitrogen is added to the familiar hydrocarbons:

Substance	Expanded structural formula	Simplified structural formula	Skeletal formula
Aminomethane (methylamine)	H-C-N\H;H\|#C\|H	CH3-NH2	\NH2
Aminoethane (ethylamine)	H-C-C-N\H;H\|#C\|H;H\|#3\|H	CH3-CH2-NH2	/\NH2
Dimethylamine	H-C-N<`\|H>-C-H; H\|#-3\|H; H\|#2\|H	$L(1.3)H/N<_(A80,w+)CH3>\dCH3	/N<_(y-.5)H>\
Aminobenzene (Aniline)	H\N\|C\\C\|C<\H>`//C<\|H>`\C<`/H>`\|\|C<`\H>/	NH2\|C\\CH\|CH`//C<_(y.5)H>`\HC`\|\|HC/	NH2\|\\|`/`\`\|/_o
Triethylamine	$slope(45)H-C-C/N\C-C-H;H\|#2\|H; H\|#3\|H; H\|#5\|H;H\|#6\|H; #N`\|C<`-H><-H>`\|C<`-H><-H>`\|H	CH3-CH2-N<`\|CH2-CH3>-CH2-CH3	\/N<`\|/>\\|

As you probably already guessed from the names, all these substances are united under the general name amines. The functional group ()-NH2 is called amino group. Here are some general formulas of amines:

In general, there are no special innovations here. If these formulas are clear to you, then you can safely engage in further study of organic chemistry using a textbook or the Internet.
But I would also like to talk about formulas in inorganic chemistry. You will see how easy it is to understand them after studying the structure of organic molecules.

Rational formulas

It should not be concluded that inorganic chemistry is easier than organic chemistry. Of course, inorganic molecules tend to look much simpler because they don't tend to form complex structures like hydrocarbons. But then we have to study more than a hundred elements that make up the periodic table. And these elements tend to combine according to their chemical properties, but with numerous exceptions.

So, I won’t tell you any of this. The topic of my article is chemical formulas. And with them everything is relatively simple.
Most often used in inorganic chemistry rational formulas. And now we’ll figure out how they differ from those already familiar to us.

First, let's get acquainted with another element - calcium. This is also a very common element.
It is designated Ca and has a valency of two. Let's see what compounds it forms with the carbon, oxygen and hydrogen we know.

Substance	Structural formula	Rational formula
Calcium oxide	Ca=O	CaO
Calcium hydroxide	H-O-Ca-O-H	Ca(OH)2
Calcium carbonate	$slope(45)Ca`/O\C\|O`\|/O`\#1	CaCO3
Calcium bicarbonate	HO/`\|O\|\O/Ca\O/`\|O\|\OH	Ca(HCO3)2
Carbonic acid	H\|O\C\|O`\|/O`\|H	H2CO3

At first glance, you can see that the rational formula is something between a structural and a gross formula. But it is not yet very clear how they are obtained. To understand the meaning of these formulas, you need to consider the chemical reactions in which substances participate.

Calcium in its pure form is a soft white metal. It does not occur in nature. But it is quite possible to buy it at a chemical store. It is usually stored in special jars without access to air. Because in air it reacts with oxygen. Actually, that’s why it doesn’t occur in nature.
So, the reaction of calcium with oxygen:

2Ca + O2 -> 2CaO

The number 2 before the formula of a substance means that 2 molecules are involved in the reaction.
Calcium and oxygen produce calcium oxide. This substance also does not occur in nature because it reacts with water:

CaO + H2O -> Ca(OH2)

The result is calcium hydroxide. If you look closely at its structural formula (in the previous table), you can see that it is formed by one calcium atom and two hydroxyl groups, with which we are already familiar.
These are the laws of chemistry: if a hydroxyl group is added to an organic substance, an alcohol is obtained, and if it is added to a metal, a hydroxide is obtained.

But calcium hydroxide does not occur in nature due to the presence of carbon dioxide in the air. I think everyone has heard about this gas. It is formed during the respiration of people and animals, the combustion of coal and petroleum products, during fires and volcanic eruptions. Therefore, it is always present in the air. But it also dissolves quite well in water, forming carbonic acid:

CO2 + H2O<=>H2CO3

Sign<=>indicates that the reaction can proceed in both directions under the same conditions.

Thus, calcium hydroxide, dissolved in water, reacts with carbonic acid and turns into slightly soluble calcium carbonate:

Ca(OH)2 + H2CO3 -> CaCO3"|v" + 2H2O

A down arrow means that as a result of the reaction the substance precipitates.
With further contact of calcium carbonate with carbon dioxide in the presence of water, a reversible reaction occurs to form an acidic salt - calcium bicarbonate, which is highly soluble in water

CaCO3 + CO2 + H2O<=>Ca(HCO3)2

This process affects the hardness of the water. When the temperature rises, bicarbonate turns back into carbonate. Therefore, in regions with hard water, scale forms in kettles.

Chalk, limestone, marble, tuff and many other minerals are largely composed of calcium carbonate. It is also found in corals, mollusk shells, animal bones, etc...
But if calcium carbonate is heated over very high heat, it will turn into calcium oxide and carbon dioxide.

This short story about the calcium cycle in nature should explain why rational formulas are needed. So, rational formulas are written so that the functional groups are visible. In our case it is:

In addition, individual elements - Ca, H, O (in oxides) - are also independent groups.

Ions

I think it's time to get acquainted with ions. This word is probably familiar to everyone. And after studying the functional groups, it doesn’t cost us anything to figure out what these ions are.

In general, the nature of chemical bonds is usually that some elements give up electrons while others gain them. Electrons are particles with a negative charge. An element with a full complement of electrons has zero charge. If he gave away an electron, then its charge becomes positive, and if he accepted it, then it becomes negative. For example, hydrogen has only one electron, which it gives up quite easily, turning into a positive ion. There is a special entry for this in chemical formulas:

H2O<=>H^+ + OH^-

Here we see that as a result electrolytic dissociation water breaks down into a positively charged hydrogen ion and a negatively charged OH group. The OH^- ion is called hydroxide ion. It should not be confused with the hydroxyl group, which is not an ion, but part of some kind of molecule. The + or - sign in the upper right corner shows the charge of the ion.
But carbonic acid never exists as an independent substance. In fact, it is a mixture of hydrogen ions and carbonate ions (or bicarbonate ions):

H2CO3 = H^+ + HCO3^-<=>2H^+ + CO3^2-

The carbonate ion has a charge of 2-. This means that two electrons have been added to it.

Negatively charged ions are called anions. Typically these include acidic residues.
Positively charged ions - cations. Most often these are hydrogen and metals.

And here you can probably fully understand the meaning of rational formulas. The cation is written in them first, followed by the anion. Even if the formula does not contain any charges.

You probably already guess that ions can be described not only by rational formulas. Here is the skeletal formula of the bicarbonate anion:

Here the charge is indicated directly next to the oxygen atom, which received an extra electron and therefore lost one line. Simply put, each extra electron reduces the number of chemical bonds depicted in the structural formula. On the other hand, if some node of the structural formula has a + sign, then it has an additional stick. As always, this fact needs to be demonstrated with an example. But among the substances familiar to us there is not a single cation that consists of several atoms.
And such a substance is ammonia. Its aqueous solution is often called ammonia and is included in any first aid kit. Ammonia is a compound of hydrogen and nitrogen and has the rational formula NH3. Consider the chemical reaction that occurs when ammonia is dissolved in water:

NH3 + H2O<=>NH4^+ + OH^-

The same thing, but using structural formulas:

H|N<`/H>\H + H-O-H<=>H|N^+<_(A75,w+)H><_(A15,d+)H>`/H + O`^-# -H

On the right side we see two ions. They were formed as a result of one hydrogen atom moving from a water molecule to an ammonia molecule. But this atom moved without its electron. The anion is already familiar to us - it is a hydroxide ion. And the cation is called ammonium. It exhibits properties similar to metals. For example, it may combine with an acidic residue. The substance formed by combining ammonium with a carbonate anion is called ammonium carbonate: (NH4)2CO3.
Here is the reaction equation for the interaction of ammonium with a carbonate anion, written in the form of structural formulas:

2H|N^+<`/H><_(A75,w+)H>_(A15,d+)H + O^-\C|O`|/O^-<=>H|N^+<`/H><_(A75,w+)H>_(A15,d+)H`|0O^-\C|O`|/O^-|0H_(A-15,d-)N^+<_(A105,w+)H><\H>`|H

But in this form the reaction equation is given for demonstration purposes. Typically equations use rational formulas:

2NH4^+ + CO3^2-<=>(NH4)2CO3

Hill system

So, we can assume that we have already studied structural and rational formulas. But there is another issue that is worth considering in more detail. How do gross formulas differ from rational ones?
We know why the rational formula of carbonic acid is written H2CO3, and not some other way. (The two hydrogen cations come first, followed by the carbonate anion.) But why is the gross formula written CH2O3?

In principle, the rational formula of carbonic acid may well be considered a true formula, because it has no repeating elements. Unlike NH4OH or Ca(OH)2.
But an additional rule is very often applied to gross formulas, which determines the order of elements. The rule is quite simple: carbon is placed first, then hydrogen, and then the remaining elements in alphabetical order.
So CH2O3 comes out - carbon, hydrogen, oxygen. This is called the Hill system. It is used in almost all chemical reference books. And in this article too.

A little about the easyChem system

Instead of a conclusion, I would like to talk about the easyChem system. It is designed so that all the formulas that we discussed here can be easily inserted into the text. Actually, all the formulas in this article are drawn using easyChem.

Why do we even need some kind of system for deriving formulas? The thing is that the standard way to display information in Internet browsers is hypertext markup language (HTML). It is focused on processing text information.

Rational and gross formulas can be depicted using text. Even some simplified structural formulas can also be written in text, for example alcohol CH3-CH2-OH. Although for this you would have to use the following entry in HTML: CH ₃-CH ₂-OH.
This of course creates some difficulties, but you can live with them. But how to depict the structural formula? In principle, you can use a monospace font:

H H | | H-C-C-O-H | | H H Of course it doesn’t look very nice, but it’s also doable.

The real problem comes when trying to draw benzene rings and when using skeletal formulas. There is no other way left except connecting a raster image. Rasters are stored in separate files. Browsers can include images in gif, png or jpeg format.
To create such files, a graphic editor is required. For example, Photoshop. But I have been familiar with Photoshop for more than 10 years and I can say for sure that it is very poorly suited for depicting chemical formulas.
Molecular editors cope with this task much better. But with a large number of formulas, each of which is stored in a separate file, it is quite easy to get confused in them.
For example, the number of formulas in this article is . They are displayed in the form of graphic images (the rest using HTML tools).

The easyChem system allows you to store all formulas directly in an HTML document in text form. In my opinion, this is very convenient.
In addition, the gross formulas in this article are calculated automatically. Because easyChem works in two stages: first the text description is converted into an information structure (graph), and then various actions can be performed on this structure. Among them, the following functions can be noted: calculation of molecular weight, conversion to a gross formula, checking for the possibility of output as text, graphic and text rendering.

Thus, to prepare this article, I only used a text editor. Moreover, I didn’t have to think about which of the formulas would be graphic and which would be text.

Here are a few examples that reveal the secret of preparing the text of an article: Descriptions from the left column are automatically turned into formulas in the second column.
In the first line, the description of the rational formula is very similar to the displayed result. The only difference is that the numerical coefficients are displayed interlinearly.
In the second line, the expanded formula is given in the form of three separate chains separated by a symbol; I think it is easy to see that the textual description is in many ways reminiscent of the actions that would be required to depict the formula with a pencil on paper.
The third line demonstrates the use of slanted lines using the \ and / symbols. The ` (backtick) sign means the line is drawn from right to left (or bottom to top).

There is much more detailed documentation on using the easyChem system here.

Let me finish this article and wish you good luck in studying chemistry.

A brief explanatory dictionary of terms used in the article

Hydrocarbons Substances consisting of carbon and hydrogen. They differ from each other in the structure of their molecules. Structural formulas are schematic images of molecules, where atoms are denoted by Latin letters and chemical bonds by dashes. Structural formulas are expanded, simplified and skeletal. Expanded structural formulas are structural formulas where each atom is represented as a separate node. Simplified structural formulas are those structural formulas where hydrogen atoms are written next to the element with which they are associated. And if more than one hydrogen is attached to one atom, then the amount is written as a number. We can also say that groups act as nodes in simplified formulas. Skeletal formulas are structural formulas where carbon atoms are depicted as empty nodes. The number of hydrogen atoms bonded to each carbon atom is equal to 4 minus the number of bonds that converge at the site. For knots formed not by carbon, the rules of simplified formulas apply. Gross formula (aka true formula) - a list of all chemical elements that make up the molecule, indicating the number of atoms in the form of a number (if there is one atom, then the unit is not written) Hill system - a rule that determines the order of atoms in the gross formula formula: carbon is placed first, then hydrogen, and then the remaining elements in alphabetical order. This is a system that is used very often. And all the gross formulas in this article are written according to the Hill system. Functional groups Stable combinations of atoms that are conserved during chemical reactions. Often functional groups have their own names and affect the chemical properties and scientific name of the substance

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 - tetraoxophosphate (V) of hydrogen , 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