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ЕР
СИ
ТЕ
Т
МІНІСТЕРСТВО ОСВІТИ І НАУКИ УКРАЇНИ
СУМСЬКИЙ ДЕРЖАВНИЙ УНІВЕРСИТЕТ
УН
ІВ
Т.В. Диченко, Т.О.Дегтярьова, А.В.Шевцова
КОНСПЕКТ ЛЕКЦІЙЗ КУРСУ “ХІМІЯ”
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
“ОСНОВНІ КЛАСИ НЕОРГАНІЧНИХ СПОЛУК”
для слухачів підготовчого відділення денної форми
навчання
СУМИ ВИД-ВО СУМДУ 2004
ТЕ
Т
1 CLASSIFICATION OF INORGANIC PURE
SUBSTANCES
Й
УН
ІВ
ЕР
СИ
All inorganic pure substances are divided into 2 groups:
elementary substances and chemical compounds. Elemental
substances are divided into metals and non-metals.
Elemental substances metals consist of atoms of chemical
elements metals, for example, potassium (K), iron (Fe), silver
(Ag) and so on. Elemental substances non-metals consist of
atoms of chemical elements non-metals, for example, chlorine
(Cl2), oxygen (O2), sulphur (S8), phosphorus (P4) and so on.
Chemical compounds are divided into classes: oxides, bases,
acids, amphoteric hydroxides, salts. Each class contains
substances similar in structure and properties.
НИ
Figure 1 – Classification of inorganic pure substances
ДЕ
Non-metals
N2, O2, P4
КИ
Й
Metals
Fe, Cu, Na
РЖ
Elemental substances
АВ
Inorganic pure
substances
Oxides
Na2O,
SO3,
Al2O3
Chemical Compounds
Bases
Al(OH)3 ,
NaOH
Acids
HCl,
H2SO4,
Н3РО4
Salts
NaCl,
KHCO3
CuOHCl
Amphoteric hydroxides
Zn(OH)2, H2ZnO2
МС
Ь
Oxides are the compounds that consist
of 2 elements, one of which is oxygen.
СУ
A general oxide formula is the following: EmOn,
where m is the number of element E atoms; n − the number
of oxygen atoms.
Т
Examples of the oxides: Na2O, CaO, SO3, N2O5.
СИ
ТЕ
Bases are the compounds that consist of one metal atom and
one or several hydroxogroups −ОН.
ІВ
ЕР
A general formula of bases is the following: Me(OH)у, where
у is the hydroxyl group number, which is equal to the metal Me
valency. The hydroxyl group is one-valent.
Examples of the bases: КОН, Са(ОН)2, Со(ОН)3. NH4OH −
the product of ammonia NH3 and water joining is also a base.
УН
Acids are the compounds that contain
hydrogen atoms, that can be substituted by metal atoms.
АВ
НИ
Й
A general formula of acids is the following: Нх(Ас),
where Ас is an acid residue; х − the hydrogen atom number,
which is equal to the valency of the acid residue.
Examples of acids: HCl, H2SO4, HNO3.
Amphoteric hydroxides are the compounds
РЖ
that have both acid and base properties.
ДЕ
Amphoteric hydroxides formulas can be written both in the
form of bases and in the form of acids.
Examples of amphoteric hydroxides:
СУ
МС
Ь
КИ
Й
Zn(OH)2 − H2ZnO2
Al(OH)3 − H3AlO3
Bases
Acids
form
form
Salts are the products of hydrogen atoms substitution
in the acid molecules by a metal or hydroxogroups in bases
molecules by an acid residues.
Hydrogen atom Н is substituted
ЕР
Hydroxide groups −ОН substitution
СИ
HCl −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−> KCl
(Acid)
by a К metal atom
(Salt)
ТЕ
Т
For example:
УН
ІВ
Ва(ОН)2−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−>Ba(NO3)2
(Base)
by acid residues −NO3
(Salt)
АВ
РЖ
ДЕ
МС
Ь
4
5
6
7
8
9
Й
3
QUIZ
What groups are inorganic pure substances divided into?
According to what property are pure substances divided into
elemental substances and compounds?
According to what property are elemental substances divided
into metals and non-metals?
Name the classes of chemical compounds.
What are oxides? Give examples.
What are bases? Give examples.
What are acids? Give examples.
What are amphoteric hydroxides? Give examples.
What are salts? Give examples.
КИ
1
2
НИ
Й
A general formula of normal salts: Mex(Ac)y,
where х is the number of metal atoms; у − the number of acid
residues. Examples of normal salts: К3РО4, MgSO4, FeCl2,
Al2(SO4)3.
PROBLEMS
СУ
1 Which substances belong to elemental substances, and
which – to compound ones: Н2, Н2О, О2, О3, Fe, Fe2O3, P4, Cs,
CO2, CO, Co, SO3, S8, N2O5, H3PO4?
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
2 Which elemental substances belong to metals, and which
– to non-metals: Na, Ca, N2, Fe, C, B, As, Mn, S, P, K, Cr, V,
Cl2, Si, Br2?
3 Choose the oxides: Ca(OH)2, H2SO4, Cr2O3, Cr(OH)2,
N2O, Al2O3, AlCl3, Fe2(SO4)3, Pb3O4, H2O?
4 Choose the bases: CO2, Co(OH)2, H2SO4, H2S, Fe(OH)3,
Ca(OH)2, N2O5, AlPO4, H3PO4, Al(OH)3, Al(OH)2Cl,
Mn(OH)2?
5 Choose the acids: Zn(OH)2, H2SiO3, (ZnOH)2CO3, H2S,
H2O, H3PO3, HCN, H2SO4, NaCl, HNO3?
6 Choose the salts: H2S, Na2S, Mg(OH)2, KCl, H2SiO3,
Na2SO4, Al2(SO4)3, H2MnO4, Ba(NO3)2?
7 Which of the following inorganic compounds are:
a) oxide; b) base; c) acid; d)salt:
a) NaCl, H2SO4, Zn(OH)2, CaO, P2O5, HМnO4, KOH,
Cu(NO3)2, HCl, Al2O3, Cu(OH)2, Al2(SO4)3;
b) Na2O, CaCl2, NaNO3, KOH, Na2SO4, H3AsO4, As2O5;
c) H2SO3, K2SO3, SO2, P4, Mg(ClO4)2, MgO, P2O5.
ДЕ
РЖ
2 NOMENCLATURE, CLASSIFICATION AND
GRAPHICAL FORMULAS OF OXIDES
Nomenclature
КИ
Й
Nomenclature refers to the writing of chemical names
and formulas by some systematic method.
МС
Ь
Oxide name = Element + Element + «Oxide»
name
valency
(in Roman
numerals)
СУ
For example: СО − carbon (II) oxide; СО2 − carbon (IV)
oxide; Fe2O3 − iron (III) oxide; FeO – iron (II) oxide.
СИ
ТЕ
Т
If the element has constant valency, it is not mentioned
in the name of the oxide. For example: К2О − potassium oxide;
Al2O3 − aluminium oxide; ВаО – barium oxide.
Classification
ІВ
ЕР
All the oxides are divided into salt-forming and non-saltforming.
Non-salt-forming oxides are the oxides,
which do not form salt when reacting with acids
or bases.
НИ
Й
УН
There are few of them. Remember 4 non-salt-forming oxides:
СО, SiO, N2O, NO.
Salt-forming oxides are the oxides,
which form salts when reacting with acids or bases.
For example:
К2О + 2HCl = 2KCl + H2O,
Acid
Salt
АВ
Oxide
РЖ
SO3 + 2NaOH = Na2SO4 + H2O.
Oxide
Base
Salt
ДЕ
Many salt-forming oxides react with water.
КИ
Й
The products of reaction of the oxides with water
are called oxides hydrates (or hydroxides).
МС
Ь
For example:
К2О + Н2О = 2КОН;
Oxide
Hydroxide
SO3 + H2O = H2SO4.
Oxide
Hydroxide
СУ
Some oxides don’t react with water. Their corresponding
hydroxides can be obtained as a result of several chemical
reactions. For example:
Т
CuO + 2HCl = CuCl2 + H2O,
ТЕ
Oxide
СuСl2 + 2NaOH = Cu(OH)2 + 2NaCl.
СИ
Hydroxide
ЕР
Any hydroxide contains hydroxogroups –OH.
О
К − О−Н
S
O
Й
H−O
О−Н
Cu
УН
Н−О
ІВ
For example:
O−H
РЖ
АВ
НИ
Hydroxides can be either bases (КОН, Cu(OH)2) or
acids (H2SO4, H3PO4). Some hydroxides are amphoterics
(Zn(OH)2 ≡ H2ZnO2).
All salt-forming oxides are divided into basic, acid and
amphoteric according to the type of the corresponding
hydroxides.
ДЕ
Basic oxides are the oxides, the hydrates
of which are the bases.
For example:
Й
Corresponds to
МС
Ь
КИ
К2О
II
CuO
MgO
СУ
Basic
oxides
I
КОН
II
Cu(OH)2
Mg(OH)2
Bases
All the basic oxides are the metal oxides.
Acid oxides are the oxides, the hydrates
ЕР
VI
H2SO4
IV
H2CO3
V
H3PO4
СИ
For example:
VI Corresponds to
SO3
IV
CO2
ТЕ
Т
of which are the acids.
ІВ
P2O5
Acids
УН
Acid
oxides
Acids
РЖ
Acid
oxides
АВ
НИ
Й
Most acid oxides are non-metal oxides. Some high
valency metal oxides are acid oxides as well.
For example:
VI
Corresponds to
VI
CrO3
H2CrO4
VII
VII
Mn2O7
HMnO4
ДЕ
Amphoteric oxides are the oxides,
which are correspondent to the amphoteric hydroxides.
КИ
Й
For example:
II
Corresponds to
ZnO
МС
Ь
Al2O3
Amphoteric
oxides
II
II
Zn(OH)2 ≡ H2ZnO2
III
III
Al(OH)3 ≡ H3AlO3
Amphoteric
hydroxides
СУ
All the amphoteric oxides are metal oxides.
So, non-metals form only acid oxides; metals form all
the basic, all the amphoteric and some acid oxides.
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
All the oxides of one-valency metals (Na2О, K2O, Cu2O
и др.) are basic. Most oxides of two-valency metals (СаО, ВаО,
FeO и др.) are also basic. Exceptions: BeO, ZnO, PbO, SnO,
which are amphoteric. Most oxides of three- and four-valency
metals are
III
III
III
IV
IV
amphoteric: Al2O3, Cr2O3, Fe2O3, PbO2, SnO2 and others.
Oxides of metals with the valency V, VI, VII are
V
VI
VII
acid: Sn2O5, CrO3, Mn2O7 and others.
Metals with changing valency can form basic,
amphoteric and acid oxides.
For example:
II
III
CrO − basic oxide; Cr2O3 − amphoteric oxide,
VI
CrO3 − acid oxide.
II
IV
MnO − basic oxide; MnO2 − amphoteric oxide;
VII
Mn2O7 − acid oxide.
Й
ДЕ
Graphical formulas
Graphical formulas of the oxides are represented in the
following way:
II II
III II
MgO Mg = O
Al2O3 O=Al−O−Al=O
Aluminium oxide
IV II
СО2 О=С=О
V II
Р2О5
Carbon (IV) oxide
Phosphorus (V) oxide
МС
Ь
КИ
Magnesium oxide
О=Р−О−Р=О
||
||
O
O
СУ
In the oxides the oxygen atoms are found only with the
atoms of the other element but not with each other.
УН
ІВ
ЕР
СИ
ТЕ
How are the names of the oxides composed?
What groups are all the oxides divided into?
What are the non-salt-forming oxides? Give examples.
What are the salt-forming oxides? Give examples.
What are the oxides hydrates (hydroxides)? Give examples.
What groups are the salt-forming oxides divided into?
What are the basic oxides? Give examples.
What are the acid oxides? Give examples.
What are the amphoteric oxides? Give examples.
What oxides do non-metals form?
What elements – metals or non-metals – form the basic and
amphoteric oxides?
Й
1
2
3
4
5
6
7
8
9
10
11
Т
QUiz
НИ
PROBLEMS
Name the following oxides: а) N2O3; b) ZnO; c) CuO; d)
PbO2; e) Mn2O3; f) MgO; g) P2O5; h) Cl2O7; i) SiO2;
g)SO3; k) K2O; l) Fe2O3.
2 Write the molecular and graphical formulas of the following
oxides: а) Mercury (II) oxide; b) Chlorine (V) oxide; c)
Manganese (VII) oxide; d) Sulphur (IV) oxide; e)Sodium
oxide; f) Iron (II) oxide; g) Silver (I) oxide; h)Lead (IV)
oxide; i) Tin (II) oxide; j) Nickel (II) oxide; k)Iodine (VII)
oxide; l) Aluminium oxide.
3 Write the formulas and name the oxides of the following
elements: а) Germanium (II); b) Phosphorus (III);
c) Silicon (II); d) Vanadium (V); e) Rubidium (I); f) Gold
(III); g) Bromine (VI); h) Nitrogen (II).
4 Classify the following salt-forming oxides: а) SO3, K2O,
N2O5, Al2O3, FeO, BaO, MnO2, P2O3, Ag2O;
b) CrO, Cr2O3, CrO3, MgO, MnO, CO2, V2O3, VO, VO2,
V2O5, Al2O3, Na2O.
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
1
Write the formulas and name the oxides and hydrates of the
following elements: Iron (III); Manganese (II, VII),
Chromium (II, III, VI), Sulphur (IV, VI), Chlorine (I, VII).
Model: Chromium oxide (II, III, VI)
II II II
III II
VI II I VI II
CrO − Cr(OH)2; Cr2O3 − Cr(OH)3;
CrO3 − H2CrO4
Chromium (II) oxide Chromium (III) oxide
Chromium (VI) oxide
Write the oxide formulas of the corresponding bases:
Mg(OH)2, LiOH, Fe(OH)3, Bi(OH)3, Cu(OH)2.
Write the formulas of the bases, which correspond to the
following oxides: NiO, K2O, Co2O3, CuO, Cs2O.
Write the formulas of the oxides that correspond to the
acids: H2SO3, H2MoO4, H3BO3, H2P2O7, HMnO4, HClO3,
H3AsO4, H2Cr2O7.
ЕР
Й
8
ІВ
7
УН
6
СИ
ТЕ
Т
5
АВ
НИ
3 NOMENCLATURE, CLASSIFICATION AND
GRAPHICAL FORMULAS OF BASES
Nomenclature
The name
The valency
= of the metal + of the metal + «Hydroxide»
РЖ
The name
of the base
СУ
МС
Ь
КИ
Й
ДЕ
For example: Fe(OH)2 − Iron (II) hydroxide; Fe(OH)3 −
iron (III) hydroxide.
If the element has the constant valency, it is not
mentioned in the name of the oxide.
For exmaple:
NaOH − sodium hydroxide; Ca(OH)2 − calcium hydroxide;
Al(OH)3 − aluminium hydroxide.
If one or several hydroxogroups are detached from the
base molecule, the base residue is formed.
The base residue is a positively charged ion that
is formed after the detachment of one or several
hydroxogroups from the base molecule.
УН
Classification
ІВ
ЕР
СИ
ТЕ
Т
The value of the positive base residuum charge is
determined by the number of the detached hydroxogroups.
For example:
Th(OH)4
− thorium (IV) hydroxide;
+
− threehydroxotorium–(IV)−ion;
Th(OH)3
− dihydroxotorium−(IV)−ion;
Th(OH)22+
3+
− hydroxotorium−(IV)−ion;
Th(OH)
4+
− thorium–(IV)−ion.
Th
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
According to the solubility in water bases are divided
into soluble and insoluble.
The soluble in water bases are called alkalis.
Alkalis are hydroxides of alkaline (Li, Na, K, Rb, Cs, Fr)
and earth-alkaline (Са, Ва, Sr, Ra) metals: NaOH, RbOH,
Ca(OH)2.
Hydroxides of all other metals are insoluble in water. For
example: Cu(OH)2, Fe(OH)2, Fe(OH)3, Al(OH)3 and others.
The number of hydroxide groups in a base molecule
defines its acidity. According to the number of hydroxogroups
in a molecule the bases are divided into:
−
monoacidic, the molecules of which contain one
hydroxogroup: NaOH, KOH, LiOH and others;
−
biacidic, the molecules of which contain two
hydroxogroups: Ca(OH)2, Fe(OH)2, Cu(OH)2 and others;
−
triacidic, the molecules of which contain three
hydroxogroups: Ni(OH)3, Bi(OH)3 and others;
−
tetraacidic base: Th(OH)4.
Five-acidic and six-acidic bases are not defined.
Т
Graphical formulas
СИ
ТЕ
In a base molecule a metal atom combines with the
atoms of oxygen in hydroxogroups. For example:
O−H
O−H
Fe−O−H
O−H
Fe(OH)3
Iron (III) hydroxide
Са
QUIZ
Й
НИ
АВ
КИ
МС
Ь
2
СУ
3
4
PROBLEMS
Find the bases among the following compounds and name
them: HNO3, NaOH, HCl, Hg(OH)2, P2O5, NaHCO3,
Mn2O7, CH3COOH, Cd(OH)2, Co(OH)3, Al(OH)2Cl,
Ra(OH)2.
Write the names and graphical formulas of the following
basses: Mg(OH)2, KOH, Ni(OH)2, Cu(OH)2, Hg(OH)2,
Ca(OH)2, Pt(OH)2, Mn(OH)3.
Write the formulas of the bases: Lead (II) hydroxide,
Ammonium hydroxide, Manganese (IV) hydroxide, Gold
(III) hydroxide.
Name the ions of the base residues, define their charge:
Й
1
РЖ
4
5
6
How are the base names composed?
What is called ‘the base residue’?
What groups are the bases divided into according to their
solubility in water? Give examples.
What is called ‘alkalis’?
What defines the base acidity?
What groups are the bases divided into according to their
acidity? Give examples.
ДЕ
1
2
3
УН
ІВ
ЕР
O−H
Ca(OH)2
Calcium
hydroxide
СИ
РЖ
АВ
8
НИ
Й
7
УН
ІВ
6
ЕР
5
ТЕ
Т
II
III
III
MnOH+х, MgOH+х, Al(OH)2+х, FeOH, Te(OH)2+х,
III
III
Cr(OH)2+х, CrOH+х.
Write
the
formulas
of
the
bases
residues:
hydroxozinc−(II)−ion,
dihydroxogold−(III)−ion,
ammonium-ion,
threehydroxolead−(IV)−ion,
hydroxomagnesium−ion, hydroxocopper−(II)−ion.
Write the names and graphical formulas of the following
bases and their residues: Ва(ОН)2, КОН, Са(ОН)2,
La(OH)3, Th(OH)4, Cr(OH)3, Cr(OH)2, Cu(OH)2, Fe(OH)3,
Fe(OH)2.
Classify the following bases according to their acidity:
PbOH, Fe(OH)2, Mn(OH)2, Co(OH)3, TlOH, Tl(OH)3 ,
Fe(OH)3, NH4OH, KOH, Mn(OH)4, Cr(OH)3, Al(OH)3,
NaOH, Pb(OH)2.
Which bases dissolve in water: Fe(OH)3, Mg(OH)2,
Ca(OH)2, KOH, Al(OH)3, NH4OH, Ba(OH)2, Cu(OH)2,
Sr(OH)2, NaOH?
ДЕ
4 CLASSIFICATION, NOMENCLATURE AND
GRAPHICAL FORMULAS OF ACIDS
КИ
Й
Review the definition of an acid (page 4).
Hydrogen atoms in the acid molecules can be replaced
by the metal atoms, as a result the salts are formed:
Replacement of H atoms
МС
Ь
Нх(Ас) −−−−−−−−−−−−−−−−−−−−−> Mex(Ac)y
by the Me atoms
СУ
Acid
Salt
Acid residues Ас are the part of both acids and salts. The
valency of an acid residue is defined by the number of hydrogen
(х) atoms in the acid molecule. For example:
Acid
Acid
Valency
СИ
ТЕ
Т
residue (Ас)
Ас
−NO3
I
HNO3
H2S
=S
II
≡P
III
H3PO4
If one or several hydrogen atoms are detached from the
acid molecule, the acid residue is formed.
Й
SO42−
HPO42−
PO43−
Acid residues
НИ
For example:
H2SO4
HSO4−
H2PO4−
H3PO4
Acids
УН
ІВ
ЕР
Acid residues are the negatively charged atom
groups or separate atoms (negative ions), that are left
after detachment of one or several hydrogen atoms
from the acid molecule.
АВ
The value of the acid residue negative charge is
determined by the number of the detached hydrogen atoms.
РЖ
Classification
СУ
МС
Ь
КИ
Й
ДЕ
The number of hydrogen atoms, that can be replaced in
an acid molecule by the metal atoms, determines the acid
basicity.
According to the basicity the acids are divided into:
−
monobasic, the molecules of which contain one hydrogen
atom: HCl, HNO3, HCN and others;
−
dibasic, the molecules of which contain two hydrogen
atoms: H2S, H2SO4, H2CO3 and others;
−
tribasic, the molecules of which contain three hydrogen
atoms: H3PO4, H3BO3, H3AsO4 and others;
−
tetrabasic: Н4Р2О7 and others.
The acids, the molecules of which contain two and more
hydrogen atoms, are called polybasic.
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
According to the number of oxygen atoms in their
molecule acids are divided into:
– oxygenfree, the molecules of which do not contain oxygen
atoms: HCl, HBr, HCN, H2S and others;
– oxoacids, the molecules of which contain oxygen atoms:
HNO3, H2SO4, H3PO4 and others.
Oxygenfree acids are water solutions of the hydrogen
compounds of non-metals of the VI and VII groups of the
periodic table H2S, H2Se, H2Te, HF, HCl, HBr, HI, and also
HSCN and HCN.
Oxoacids are the hydrates of the acid oxides, i.e. the
products of reaction of acid oxides with water.
For example:
SO3 + H2O = H2SO4
P2O5 + 3H2O = 2H3PO4
Acid
Acid
oxide
The element, the atom of which along with the hydrogen
and oxygen atoms forms the molecule of the oxoacid, is called
the acid-forming element.
For example, in the acids HNO3, H3PO4, H2SO4 the acidforming elements are N, P, S respectively.
The valency of the acid-forming element is equal to the
difference between the sum of the oxygen atoms valency and the
sum of the hydrogen atoms valency.
For example:
I х II
а) Н2SO4
The sum of the oxygen atoms valencies is: 2 ⋅ 4 = 8.
The sum of the hydrogen atoms valencies is: 1 ⋅ 2 = 2.
The sulphur valency is: х = 8 − 2 = 6;
VI
Н2SO4
I II
V
b) Н3РО4
х = 2 ⋅ 4 − 1 ⋅ 3 = 5; Н3РО4.
ЕР
СИ
ТЕ
Т
Nomenclature Oxygenfree acids
The name
The prefix The non-metal
of the oxygenfree = “hydro” + name modified + “Acid”
acid
to have an “ic”
ending
The name of
The name of the non-metal
the acid residue = modified to end in “ide”
ІВ
Table 1 – Formulas and names of oxygenfree acids, acid
residues and their salts
Formula of
acid
Name of acid
Formula
of acid
residue
Name of acid
residue
HCl
Hydrochloric
acid
Hydrofluoric
acid
Hydrobromic
acid
Hydroiodic
acid
Hydrosulfuric
acid
−Cl
Cloride
NaCl
−F
Fluoride
NaF
−Br
Bromide
NaBr
Iodide
NaI
HI
Hydrocyanic
acid
ДЕ
HCN
УН
Й
−HS
Hydrogen
sulfide
NaHS
=S
Sulfide
Na2S
−CN
Cyanide
NaCN
РЖ
H2S
−I
НИ
HBr
АВ
HF
Formula
of salt
Name of salt
Sodium
chloride
Sodium
ftouride
Sodium
bromide
Sodium
iodide
Sodium
hydrogen
sulfide
Sodium
sulfide
Sodium
cyanide
СУ
МС
Ь
КИ
Й
Oxoacids
The acid residues of oxoacids are called oxoanions.
Certain non-metals (e.g., Cl, N, P, and S) form a series of
oxoanions containing different numbers of oxygen atoms. Their
names are related to the oxidation state (the valency) of the nonmetal atom to which the O atoms are bonded, according to the
scheme.
– Increasing oxidation state (valency) –––>
hypo –ite – ite –ate per –ate
– Increasing number of oxygen atoms –––>
СИ
ТЕ
Т
In the names of acid the ending “ous” is used instead of
“ite” and “ic” instead of “ate”. The names, formulas of oxoacids,
oxoanions, and oxidation states of the non-metal atom in several
oxoacids are listed in Table 2. Also listed in the table are the
names and formulas of the compounds that result when the
hydrogen of an oxoacid is replaced by sodium.
Formula
of acid
residue
Name of acid
residue
H2CO3
Carbonic
HCO–3
NaHCO3
Silicic acid
CO32−
HsiO–3
Hydrogen
carbonate
Carbonate
Hydrogen silicate
SiO32–
NO–2
NO3−
PO33–
Silicate
Nitrite
Nitrate
Phosphorite
Na2SiO3
NaNO2
NaNO3
Na3PO3
+5
H3PO4
+4
Nitrous acid
Nitric acid
Phosphorous
acid
Phosphoric
acid
H2SO3
H2SO4
+6
+6
Н2CrO4
H2Cr2O7
+1
HClO
+7
HMnO4
+6
H2MnO4
УН
Й
Dihydrogen
phosphate
NaH2PO4
HPO42-
Hydrogen
phosphate
Phosphate
Hydrogen sulfite
Na2HPO4
SO32−
HSO4−
Sulfite
Hydrogen sulfate
Na2SO3
NaHSO4
Na2SO4
SO42−
CrO42−
Cr2O72−
Sulfate
Chromate
Dichromate
Na2CrO4
Na2Cr2O7
ClO−
Hypochlorite
NaClO
ClO2−
ClO3−
ClO4−
Chlorite
Chlorate
Perchlorate
NaClO2
NaClO3
NaClO4
MnO4−
Permanganate
NaMnO4
MnO42−
Manganate
NaMnO4
Sulfuric acid
МС
Ь
HClO2
HClO3
HClO4
СУ
+3
+5
+7
H2PO4−
Sulfurous
acid
Chromic acid
Dichromic
acid
Hypochlorous
acid
Chlorous acid
Chloric acid
Perchloric
acid
Permanganic
acid
Manganic
acid
КИ
+6
НИ
HNO2
HNO3
H3PO3
Na2CO3
NaHSiO3
РЖ
+3
+5
+3
АВ
H2SiO3
Formula
of salt
PO43HSO3−
Name of salt
ІВ
Name of acid
ДЕ
+4
Formula
of acid
Й
Oxida–
tion
state
+4
ЕР
Table 2 – Formulas and names of oxoacids, acid residues and
their salts
Na3PO4
NaHSO3
Sodium hydrogen
carbonate
Sodium carbonate
Sodium hydrogen
silicate
Sodium silicate
Sodium nitrite
Sodium nitrate
Sodium
phosphorite
Sodium
dihydrogen
phosphate
Sodium hydrogen
phosphate
Sodium phosphate
Sodium hydrogen
sulfite
Sodium sulfite
Sodium hydrogen
sulfate
Sodium sulfate
Sodium chromate
Sodium
dichromate
Sodium
hydrochlorite
Sodium chlorite
Sodium chlorate
Sodium
perchlorate
Sodium
permanganate
Sodium
manganate
Т
Graphical formulas
СИ
ТЕ
In the oxoacids the hydrogen atoms are bound to the
oxygen atoms, but not to the atoms of the acid-forming element.
For example:
O
VII
||
HClO4
H−O−Cl=O
||
O
Chloric acid
ІВ
ЕР
VI
H−O
H2SO4
H−O
O
S
O
УН
Sulfuric acid
НИ
Й
H−O
Н3PO4
H−O−P=O
H−O
Phosphoric acid
СУ
QuIZ
What is an acid?
What is the acid residue valency determined by?
What is the acid basicity?
What is the acid residue?
What are the monobasic, polybasic acids? Give examples.
What are the oxygenfree acids? Give examples.
What are the oxoacids? Give examples.
МС
Ь
1
2
3
4
5
6
7
КИ
Й
ДЕ
РЖ
АВ
In the oxoacids, with two and more acid-forming
element atoms, these atoms are bound through the oxygen
atoms. For example:
O
O
||
||
H2Cr2O7
H−O−Cr−O−Cr−O−H
||
||
O
O
Dichromic acid
The hydrates of what oxides are the oxoacids.
What is called ‘the acid-forming element’?
What is the valency of the acid-forming metal equal to?
Give the examples of the formulas and names of oxygenfree
acids and their acid residues.
12 Give the examples of formulas and names of oxoacids and
their acid residues.
ІВ
PROBLEMS
ЕР
СИ
ТЕ
Т
8
9
10
11
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
УН
1
Classify the following acids according to the basicity and
to the number of oxygen atoms: HI, H3AsO4, H2S, HNO2,
HMnO4, H2CO3.
2
Define the acid residues valency of the following acids:
H3BO3, HClO4, H2SiO3, HCN, H3SbO4, H2Cr2O7.
3
Define the valency of the acid-forming elements of the
following acids and write the graphical formulas of these acids:
HClO, H2Cr2O7, H3AsO4, H2SiO3.
4
Write formulas and names of the acids that correspond to
the following acid oxides: SO2, SO3, CO2, P2O5, N2O5, Mn2O7,
CrO3, SiO2, P2O5, Cl2O.
5
Write formulas and names of the oxides, the hydrates of
which are the following acids: H2SiO3, HNO3, H2CrO4, HClO3,
H3PO4, H2Cr2O7, H2MnO4, HClO2.
6
To which of the following oxides do the acids
correspond: MgO, Mn2O7, CO, P2O5, N2O, Cl2O7, SiO, FeO,
Na2O, NO, SO2 , CrO3. Write the formulas and names of these
acids.
7
Write the formulas and define the charge of the acid
residues: sulfate ion, hydrogen sulfate, hydrogen sulfite,
dichromate ion, carbonate ion, permanganate ion, manganate
ion, dihydrogen phosphate ion, hydrogen phosphate ion.
Model: sulfate ion − SO42−,
hydrogen sulphate ion − HSO4−.
Т
5 AMPHOTERIC HYDROXIDES
ІВ
ЕР
СИ
ТЕ
Review the definition of the amphoteric hydroxides
(page 4).
The molecular formula of any amphoteric hydroxide can
be written as a base and as an acid:
Н−О−Zn−O−H
Zn(OH)2
H2ZnO2
Base form
Acid form
Zn(OH)2
Zinc
hydroxide
O−H
АВ
Zn
Amphoteric
hydroxide
as an acid
H2ZnO2
Zinc acid
O−H
Al(OH)3
Aluminium
hydroxide
МС
Ь
СУ
O−H
Cr−O−H
O−H
–ZnO22–
Zincate
H3AlO3
Orthoaluminium
acid
–AlO33–
Orthoaluminate
HAlO2 +H2O
Metaaluminium
acid
–AlO2–
Metaaluminate
КИ
Й
ДЕ
РЖ
O−H
Al−O−H
O−H
Acid residue
Й
Amphoteric
hydroxide
as a base
НИ
Graphic
formula
УН
Every amphoteric base can be given the name both of the
base or of the acid:
H3CrO3
Cr(OH)3
Orthochromic
Chrome (III) acid
HCrО2+H2O
hydroxide
Metachromic acid
–CrO33–
Orthochromite
−CrO2
Metachromite
ТЕ
What are the amphoteric hydroxides? Give examples.
Write the formulas of the amphoteric hydroxides you know.
СИ
1
2
Т
QUIZ
PROBLEMS
УН
ІВ
ЕР
Write the formulas of the following amphoteric hydroxides
in the form of the acids and define the valency of acid residues
in these acids:
Cr(OH)3, Sr(OH)2, Pb(OH)2.
Й
6 CLASSIFICATION, NOMENCLATURE AND
GRAPHICAL FORMULAS OF SALTS
НИ
The salts are divided into three groups: normal, acid and
basic.
АВ
NORMAL SALTS
ДЕ
РЖ
Normal salts are the products of complete
replacement of hydrogen atoms in the acid
molecule by the atoms of a metal or the
products of the full replacement of hydroxide
groups in the base molecule by acid residues.
Й
For example:
Full replacement of the hydrogen atoms
МС
Ь
КИ
Н2SO4 −−−−−−−−−−−−−−−−−−−−−−−−−−> Na2SO4
Acid
by the metal atoms
Normal salt
Full replacement of the hydroxogroups
СУ
Fe(OH)3 −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−> Fe(NO3)3
Base
by the acid residua
Normal salt
ТЕ
The name
The name
The valency
The name of
of the normal = of the metal + of the metal + acid residue
salt
Т
Nomenclature
ЕР
СИ
For example: NaCl − sodium chloride, Fe(NO3)2 − iron
(II) nitrate, Fe2(SO4)3 − iron (III) sulfate, Ca3(PO4)2 − calcium
phosphate.
Graphic formulas
НИ
Й
УН
ІВ
When drawing graphic formulas of the normal salts one
should replace hydrogen atoms by the metal atoms in the
graphical formulas of the corresponding acids, taking into
account the metal valency.
Let us chart the graphic formula of barium sulphate
ВaSO4. This salt contains acid residue of sulfuric acid H2SO4:
H−−−− O
O
АВ
S
O
РЖ
H−−−−O
КИ
Й
ДЕ
Barium valency is two, so one Ba atom replaces two
hydrogen atoms:
О
Ва
O
S
O
O
СУ
МС
Ь
Let us chart the graphical formula of iron (III) sulfate
Fe2(SO4)3. One molecule of this salt contains 3 acid residues of
sulfuric acid; one atom of the three-valency iron replaces 3
hydrogen atoms:
S
O
O
S
Т
O
O
O
ЕР
O
O
III
||
III
Fe−−O−−S−−O−−Fe
||
O
ТЕ
O
СИ
O
УН
ІВ
Remember! In the molecule of a normal salt the sum of
the metal atoms valencies is equal to the sum of acid residues
valencies.
ACID SALTS
O Incomplete replacement of hydrogen atoms Na−O
O
−−−−−−−−−−−−−−−−−−−−−−−−−>
S
by the metal atoms
H−O
O
H−O
O
Acid
I
I
(dibasic)
Na HSO4
Acid salt
РЖ
H−O
АВ
For example:
НИ
Й
Acid salts are the products of incomplete replacement
of hydrogen atoms in the molecule of polybasic acids
by the metal atoms.
Й
ДЕ
S
МС
Ь
КИ
Dibasic acid with any metal forms one normal and one
acid salt.
СУ
Tribasic acid with any metal forms one normal and two
acid salts.
Replacement
of one hydrogen
ТЕ
Т
H−O
I II
I
H−O−P=O Вa(H2PO4)2
O
atom
СИ
Вa
ЕР
O
I
H−O−P=O
H−O
H−O
II O
II
Вa−O−P=O
H−O
ІВ
Replacement
УН
H−O−P=O −−−
of 2 hydrogen
atoms
Acid salts
O III
|| O
II
O−P−O−−−Вa
НИ
Й
H−O
II II
ВaHPO4
II
Ba
АВ
Replacement
of 3 hydrogen
Nomenclature
Й
ДЕ
РЖ
atoms
II III
II Вa3(PO4)2
O−P−O−−Вa
|| O
O III
The molecules of an acid salt contain varying number of
КИ
atoms.
МС
Ь
The name of The name of The valency ‘hydrogen’
The name
the acid salt = the metal + of the metal + or ‘dihydrogen’ + of acid residue
СУ
For example: NaHCO3 − sodium hydrogen carbonate, КН2РО4 −
potassium dihydrogen phosphate, FeHPO4 − iron (II) phosphate.
СИ
ТЕ
Т
Remember! Prefix di- is used for modifying the acid salt with
one acid residue bound with two hydrogen atoms.
For example: КН2РО4 − potassium dihydrogen phosphate,
Са(Н2РО4)2 − calcium dihydrogen phosphate.
ATTENTION!
−O
I
Н−О−–Р=О or –Н2РО4, Н2РО4–
Н−О
Н−О
atom
Н−О−Р=О −−−−
dihydrophosphate
II
Н−О
−O
−2 hydrogen −О−–Р=О or
=НРО4,НРО42–
atoms Н−О
hydrophosphate
Й
УН
ІВ
ЕР
− 1hydrogen
НИ
basic salts
O−H
−−−−−−−−−−−−−−−> Ва
Cl
I
I
Ва OH Cl
Incomplete replacement
O−H
O
O−H of hydroxogroups
by acid residues
||
Base
−−−−−−−−−−−−−−−−−−> H−O−Ва−O−S−O−–Ва−O−H
(biacidic)
||
МС
Ь
КИ
Й
Ва
ДЕ
For example:
РЖ
АВ
Basic salts are the products of incomplete replacement
of hydroxogroups in the molecules of polyacidic bases
by acid residues.
О
I
II
Basic salts (ВаOH)2SO4
СУ
A biacidic base forms one normal and one basic salts
with the given acid residue.
A triacidic base forms one normal and two basic salts
with the given acid residue.
O
I
I
O−N=O
Fe−O−H
Fe(OH)2NO3
O−H
ТЕ
Т
Replacement of 1
O−H
Fe−O−H
O−H
СИ
hydroxogroup
by the acid residue
O
O−N=O II
I
O
Fe−O−N=O FeOH(NO3)2
O−H
O
O−N=O III
I
O
Fe−O−N=O Fe(NO3)3
O−N=O
O
Basic salts
ЕР
Replacement of 2
hydroxogroups
by the acid residues
ІВ
Base
(triacidic)
Й
hydroxogroups
by the acid residues
УН
Replacement of 3
НИ
Nomenclature
АВ
The molecules of a basic salt contain hydroxide groups.
РЖ
The name of
The name of The valency ‘hydroxo’
The name of
the basic salt = the metal + of the metal + or ‘dihydroxo’ + acid residue
ДЕ
For example: СаОНСl − calcium hydroxochloride, (СаОН)2SO4
− calcium hydroxosulfate, FeOH(NO3)2 − iron (III)
hydroxonitrate.
МС
Ь
КИ
Й
ATTENTION!
−1 hydroxide
group (ОН)
I
Fe−OH
OH
СУ
OH
Fe−OH
OH
or
−Fe(OH)2,Fe(OH)2+
II
−2 hydroxide
or =FeOH, FeOH2+
Fe−
group (ОН)
OH
ТЕ
СИ
ЕР
5
What are salts?
What types are salts divided into?
What are normal salts? Give examples.
What are acid salts? Give examples. What atoms and groups
of atoms do the molecules of acid salts contain?
What are basic salts? Give examples. What atoms and
groups of atoms do the basic salts contain?
УН
PROBLEMS
ІВ
1
2
3
4
Т
quIZ
The following substances are given: К2О, HCl, FeBr3,
Cu(OH)2, (CaOH)3PO4, HNO3, MnSO4, NaHS. Write out
the salts formulas, define to which type each salt belongs.
2 Classify and name the following salts:
Cu(NO3)2, (ZnOH)2S, Pb(HSO4)2, BaI2, [Al(OH)2]2SO3,
Fe(H2PO4)2, Na2SiO3, KHS.
3 Write the molecular and graphical formulas of the following
salts:
а) Sodium dihydrophosphate;
b) Aluminium sulphite;
c) Zinc hydroxosulphate;
d) Aluminium dihydroxonitrate;
e) Iron (III) bromide;
f) Barium hydrocarbonate;
g) Calcium hydroxosilicate;
h) Potassium permanganate;
i) Sodium dichromate;
j) Iron (II) hydrosulphite.
4 Write the molecular and graphical formulas of the normal
and acid salts that can be obtained as a result of the
replacement of:
а) hydrogen atoms in the molecule of phosphoric acid by the
barium atoms;
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
1
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
b) hydrogen atoms in the molecule of hydrosulphuric acid by
the aluminium atoms;
c) hydrogen atoms in the molecule of phosphoric acid bye
the iron atoms.
Name these salts.
5 Write the molecular and graphical formulas of normal and
basic salts which can be obtained as a result of the
replacement of:
а) hydroxogroups in the molecule of Al(OH)3 by the acid
residues of sulphuric acid;
b) hydroxogroups in the molecule of Са(ОН)2 by the acid
residues of phosphoric acid.
Name these salts.
6 Write the molecular and graphical formulas of the normal
salts that can be obtained as a result of the replacement in a
molecule of amphoteric hydroxide Zn(OH)2:
а) hydroxogroups by the acid residues of nitric acid;
b) hydrogen atoms by sodium atoms. Name these salts.
7 Name the substances: Zn(OH)2, MgO, P2O3, NaHCO3,
H3PO3, Fe2(SO4)3, KOH, (AlOH)3(PO4)2, Ba(MnO4)2, CO,
HI. Define the class each substance belongs to.
8 Write the molecular and graphical formulas of the following
substances and define which class each substance belongs
to:
а) Copper (II) hydroxocarbonate;
b) Nitrogen (V) oxide;
c) Nickel (II) hydroxide;
d) Barium hydrophosphate;
e) Chlorine acid;
f) Chrome (III) hydroxide;
g) Potassium chlorate;
h) Hydrosulphuric acid;
i) Sodium zincate.
ТЕ
Т
7 OXIDES, THEIR PROPERTIES AND THE WAYS
OF THEIR PREPARATION
СИ
Physical properties of oxides
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
According to their physical state, oxides are divided into 3
groups: solid (K2O, Al2O3, P2O5), liquid (SO3, N2O4) and
gaseous (CO2, NO2, SO2).
According to their solubility in water oxides are divided into
soluble (SO2, CO2, K2O) and insoluble (CuO, FeO, SiO2,
Al2O3).
All acid oxides, except SiO2, dissolve in water. Among basic
oxides the soluble ones are only oxides of alkaline metals (Li2O,
Na2O, K2O, Rb2O, Cs2O) and alkaline-earth metals (СаО, SrO,
BaO). Amphoteric oxides do not dissolve in water.
Oxides can be of different colours, for example: copper oxide
(II) CuO is black, nickel oxide (II) NiO is green, calcium oxide
СаО is white.
According to their chemical properties salt-forming oxides
are divided into basic, acid and amphoteric ones.
Chemical properties of basic oxides
ДЕ
1 The common property of all the basic oxides is their ability
to react with acids to produce salt and water.
КИ
Й
Basic oxide + Acid = Salt + Н2О.
МС
Ь
For example:
MgO + 2HCl = MgCl2 + H2O,
СУ
Magnesium
oxide
Magnesium
chloride
Fe2O3 + 3H2SO4 = Fe2(SO4)3 + 3H2O.
Iron (III)
oxide
Sulfuric
acid
Iron (III)
sulfate
=
Salt
For example:
Calcium
carbonate
ІВ
Carbon
oxide
ЕР
СаО + СО2 = СаСО3,
Calcium
oxide
Phosphorus Sodium
oxide
phosphate
УН
3Na2O + P2O5 = 2Na3PO4.
Sodium
oxide
ТЕ
Acid
oxide
+
СИ
Basic
oxide
Т
2 Basic oxides react with acid oxides to produce salts.
АВ
НИ
Й
3 Oxides of alkaline and alkaline-earth metals react with
water to produce soluble bases (alkalis):
Oxide + Н2О = Alkali.
For example:
К2О + Н2О = 2КОН.
Potassium
hydroxide
РЖ
Potassium
oxide
ДЕ
Chemical properties of acid oxides
КИ
Й
1 The common property of all the acid oxides is their ability
to react with bases to produce salt and water:
СУ
МС
Ь
Acid
oxide
+ Base = Salt +
Н2О.
In order to write a correct formula of the salt produced one
should know which acid corresponds to the given acid oxide. In
the examples given below under the formulas of acid oxides the
formulas of the corresponding acids are written:
Т
Sodium
hydroxide
Sodium
carbonate
ТЕ
Carbonic
acid
= Na2CO3 + H2O;
б) N2O5 + Ba(OH)2 = Ba(NO3)2 + H2O.
(HNO3)
Barium
nitrate
ЕР
Barium
hydroxide
ІВ
Nitric
acid
СИ
а) СО2 + 2NaOH
(Н2СО3)
Н2О
=
Acid.
Й
+
НИ
Acid oxide
УН
2 Acid oxides react with basic oxides to produce salts (see:
chemical properties of basic oxides).
3 Most acid oxides react with water to produce acids.
For example:
АВ
SO3 + H2O = H2SO4,
Sulfur (VI)
oxide
Sulfuric
acid
РЖ
N2O5 + H2O = 2HNO3.
Nitric
acid
ДЕ
Nitrogen (V)
oxide
Й
Very few acid oxides don’t react with water. The most wellknow is silicon (IV) oxide SiO2.
КИ
Chemical properties of amphoteric oxides
МС
Ь
1 Amphoteric oxides react with acids to produce salts and
water.
СУ
Amphoteric
oxide
+ Acid = Salt + Н2О.
Nitric
acid
= Zn(NO3)2 + 2H2O.
Т
Zinc
oxide
Zinc
nitrate
ТЕ
For example:
ZnO + 2HNO3
ЕР
СИ
In these reactions amphoteric oxides play the role of basic
oxides.
2 Amphoteric oxides react with alkalis to produce salt and
water.
Soluble
base (alkali) = Salt + Н2О.
УН
ІВ
Amphoteric
oxide
+
Й
For example:
ZnO + 2KOH = K2ZnO2 + H2O.
Potassium
hydroxide
Potassium
zincate
НИ
Zinc
oxide
ДЕ
Amphoteric
oxide
РЖ
АВ
In these reactions amphoteric oxides play the role of acid
oxides.
3 Amphoteric oxides when heated react with acid oxides to
produce salts.
КИ
Й
For example:
ZnO + CO2
МС
Ь
Zinc
oxides
+
Acid
oxide
t0
= Salt.
t0
= ZnCO3.
Carbon (IV) Zinc
oxide
carbonate
СУ
4 Amphoteric oxides when heated react with basic oxides to
produce salts.
Amphoteric
oxide
+
Basic
oxide
t0
=
Salt.
Т
For example:
СИ
oxide
zincate
ЕР
oxide
ТЕ
t0
ZnO + Na2O = Na2ZnO2.
Zinc Sodium Sodium
Ways of oxide preparation
2Mg + O2 =
НИ
C + O2
2MgO,
Й
УН
ІВ
Oxides can be prepared by different ways:
1 By means of combining elemental substances with oxygen:
Metal
or
+
О2 = Oxide
non-metal
Magnesium oxide
=
CO2.
АВ
Carbon (IV)
oxide
ДЕ
РЖ
2 By means of decomposition of some oxoacids:
t0
Oxoacid = Acid oxide + Н2О
Й
t0
H2SO3 = SO2 + H2O.
Sulfur (IV)
oxide
КИ
Sulfurous
acid
СУ
МС
Ь
3 By means of decomposition of insoluble bases:
t0
Insoluble = Basic + Н2О.
base
oxide
t0
Cu(OH)2 = CuO + H2O.
Copper (II)
hydroxide
Copper (II)
oxide
Calcium Carbon (II)
oxide
oxide
ЕР
Calcium
carbonate
СИ
ТЕ
Т
4 By means of decomposition of some salts when heated:
t0
Salt = Basic oxide + Acid oxide
t0
СаСО3 = СаО + СО2.
QUIZ
НИ
Й
УН
ІВ
1 What are the physical properties of oxides?
2 What are the chemical properties of the following oxides
classes:
а) basic oxides;
b) acid oxides;
c) amphoteric oxides.
3 What are the ways of oxide preparation?
АВ
PROBLEMS
,
,
,
,
,
.
Й
ДЕ
РЖ
1 Complete the equations of the reactions:
BaO + H2O =
,
SO2 + H2O =
Li2O + H2O =
,
K2O + SO3 =
CO2 + H2O =
,
Ca(OH)2 + CO2 =
N2O3 + H2O =
,
Al2O3 + P2O5 =
CuO + H2SO4 =
,
SnO + HNO3 =
NaOH + H2SO4 =
,
SnO + Na2O =
МС
Ь
КИ
2 Write the equations of the reactions of all possible ways of
producing chromium (III) oxide, carbon (IV) oxide, calcium
oxide.
СУ
3 Which of the following substances will carbon (IV) oxide
react with: MgO, NaCl, AgNO3, NaOH, ZnO? Write the
equations.
ТЕ
Т
4 Which of the following substances will zinc oxide react
with: SO3, P2O5, CaO, Ba(OH)2, CaCO3, BaSO4? Write the
molecular and ionic equations.
ЕР
СИ
5 Which of the following substances will barium oxide react
with: Al, Al2O3, S, SO2, H2SO4, Na2SO4? Write the molecular
and ionic equations.
УН
ІВ
6 Which of the following substances will nitrogen (V) oxide
react with: KOH, Al, Al2O3, Al(OH)3, H2O? Write the molecular
and ionic equations.
НИ
Й
8 BASES, THEIR PROPERTIES AND THE WAYS OF
THEIR PREPARATION
АВ
Physical properties of bases
ДЕ
РЖ
All the bases are solid substances (except ammonium
hydroxide – NH4OH).
Bases can be of different colours: potassium hydroxide КОН
is white, copper (II) hydroxide Cu(OH)2 − blue, iron (III)
hydroxide Fe(OH)3 is red-brown.
Chemical properties of bases
МС
Ь
КИ
Й
The main properties of bases are explained by the presence in
their solutions of anions ОН−, that are formed in the result of
base molecule electrolytic dissociation:
Ме(ОН)у ⇔ Меу+ + уОН−.
СУ
1 Water solutions of alkalis turn the indicator colouring
(Table 3).
Indicator colouring
ЕР
СИ
Violet
Colourless
Orange
Litmus
Phenolphthalein
Methylorange
Indicator colouring
in an alkali
solution (рН > 7)
Dark blue
Crimson
Yellow
ТЕ
Indicator
Т
Table 3 – Indicator colouring in alkali solutions
ІВ
2 Bases react with acids to produce salt and water.
Potassium
hydroxide
= KCl + H2O;
АВ
а) КОН + HCl
НИ
For example:
Й
Base + Acid = Salt + Н2О.
УН
The reaction between acids and bases
is called neutralization reaction.
Hydrochloric Potassium
acid
chloride
Nitric
acid
Iron
nitrate
ДЕ
Iron
hydroxide
РЖ
b) Fe(OH)2 + 2HNO3 ⇔ Fe(NO3)2 + 2H2O.
3 Alkalis react with acid oxides to produce salt and water.
Й
Alkali + Acid oxide = Salt + Н2О.
КИ
For example:
Са(ОН)2 + СО2
МС
Ь
Calcium
hydroxide
=
Carbon (II)
oxide
СаСО3 ↓ + Н2О.
Calcium
carbonate
СУ
4 Alkali solutions react with salt solutions, if an insoluble
base or an insoluble salt is produced.
For example:
2NaOH + CuSO4 = Cu(OH)2 ↓ + Na2SO4,
Copper
sulfate
Copper
hydroxide
Sodium
sulfate
ЕР
Sodium
hydroxide
Т
+ New
salt.
ТЕ
New
base
СИ
Alkali + Salt
=
solution solution
Ba(OH)2 + Na2SO4 = 2NaOH + BaSO4 ↓.
Sodium
sulfate
Sodium
hydroxide
Barium
sulfate
ІВ
Barium
hydroxide
НИ
Й
УН
5 Bases that are insoluble in water decompose when heated
into basic oxide and water.
t0
Insoluble base = Basic oxide + Н2О.
АВ
For example:
t0
Cu(OH)2 = CuO + H2O,
Copper (II)
oxide
РЖ
Copper (III)
hydroxide
Iron (II)
oxide
Preparation of bases
КИ
Й
Iron (III)
hydroxide
ДЕ
t0
2Fe(OH)3 = Fe2O3 + 3H2O.
СУ
МС
Ь
Bases can be prepared in different ways.
1 Preparation of soluble bases:
а) by reaction of alkaline and alkaline-earth metals with water
Ме + Н2О = Soluble base (alkali) + Н2 ↑,
where Ме is an alkaline or alkaline-earth metal,
for example:
2Na + 2H2O = 2NaOH + H2 ↑;
СИ
ТЕ
Т
b) by reaction of oxides of alkaline and alkaline-earth metals
with water,
for example:
Na2O + H2O = 2NaOH,
BaO + H2O = Ba(OH)2.
ІВ
ЕР
2 Preparation of insoluble bases by reaction of alkalis with
soluble salts of metals.
УН
Soluble base (alkali) + Salt = Insoluble base↓ + Salt.
НИ
Й
For example:
2NaOH + FeSO4 = Fe(OH)2 ↓ + Na2SO4.
QUIZ
РЖ
АВ
1 What are the physical and chemical properties of bases?
2 What is the neutralization reaction? Give examples.
3 What are the ways of base preparation?
ДЕ
PROBLEMS
Й
1 Write the equations of 2 reactions of preparation:
а) calsium hydroxide; b) iron (III) hydroxide.
МС
Ь
КИ
2 Which of the following substances will potassium
hydroxide react with: H2SO4, Zn, ZnO, KH2PO4, SO2? Write the
molecular and ionic equations.
СУ
3 Which of the following substances will potassium
hydroxide react with: HNO3 , CaO, CO2, CuSO4, Cu(OH)2,
P2O5? Write the molecular and ionic equations.
ТЕ
Т
4 Can a solution containing simultaneously the following
substances: Ba(OH)2 and HCl; NaCl and NaOH; H2SO3 and
Ca(OH)2?
ЕР
СИ
5 By what reactions can nickel (II) oxide NiO be obtained of
nickel (II) sulphate NiSO4?
ІВ
9 ACIDS, THEIR PROPERTIES AND THE WAYS OF
THEIR PREPARATION
УН
Physical properties of acids
ДЕ
РЖ
АВ
НИ
Й
Acids can be solid (for example, orthophosphoric acid
Н3РО4, boric acid Н3ВО3, iodine acid HIO4) and liquid (for
example, sulfuric acid H2SO4, nitric acid HNO3). Most acids
solute in water.
Some acids are solutions of gases in water (for example,
chlorohydrogen acid HCl, sulfurohydrogen acid H2S).
Chemical properties of acids
Common properties of acids in water solutions are caused by
the presence of Н+ ions. They are formed in the result of the
electrolytic dissociation of the acid molecules:
НАс ⇔ Н+ + Ас−.
КИ
Й
1 All the acids change indicator colouring in the following
way (Table 4).
Table 4 − Indicator colouring in acid solutions
СУ
МС
Ь
Indicator
Litmus
Methylorange
Phenolphthalein
Indicator colouring
Violet
Orange
Colourless
Indicator colouring
in an acid solution
(рН < 7)
Red
Red
Colourless
Phosphoric
acid
Sodium
hydroxide
Sodium
phosphate
H3PO4 + NaOH ⇔ NaH2PO4
Cu(OH)2 ⇔ CuCl2 + 2H2O,
+
Hydrochloric
acid
Copper
hydroxide
НИ
2HCl
+ H2O,
Й
Sodium
dihydrophosphate
УН
Sodium
hydrophosphate
ІВ
H3 PO4 + 2NaOH ⇔ Na2HPO4 + 2H2O,
ЕР
СИ
ТЕ
Т
2 Acids react with bases to form salt and water (the
neutralization reaction). The examples of the neutralization
reaction which produce normal salts were considered in
paragraph 8. If in the neutralization reactions polybasic acids or
polyacid bases take part, the products of the reaction can be not
only normal salts, but also acid or basic salts.
For example:
H2PO4 + 3NaOH ⇔ Na3PO4 + 3H2O,
Copper
chloride
АВ
HCl + Cu(OH)2 ⇔ CuOHCl + H2O.
РЖ
Hydroxocopper
chloride
3 Acids react with basic oxides to produce salt and water.
ДЕ
Acid + Basic oxide = Salt + Н2О.
Й
For example:
КИ
а) 2HCl + CaO = CaCl2 + H2O;
Calcium
chloride
МС
Ь
b) 3H2SO4 + Fe2O3 = Fe2(SO4)3 + 3H2O.
Sulphuric
acid
Iron (III)
sulfate
СУ
4 Acids react with amphoteric oxides to produce salt and
water.
Т
Acid + Amphoteric oxide = Salt + Н2О.
Zinc
nitrate
СИ
Nitric
acid
ТЕ
For example:
2HNO3 + ZnO = Zn(NO3)2 + H2O.
ЕР
5 Acids react with amphoteric hydroxides to produce salt and
water.
Chromium (III)
hydroxide
Chromium (III)
chloride
Й
Hydrochloric
acid
УН
ІВ
Acid + Amphoteric hydroxide = Salt + Н2О.
For example:
3HCl
+ Cr(OH)3 = CrCl3 + 3H2O.
АВ
НИ
6 Acids react with some normal salts to produce a new salt
and a new acid. These reactions are possible if in the result an
insoluble salt or a weaker acid than the initial one is formed.
РЖ
Acid + Salt = Salt + Acid.
For example:
а) HCl + AgNO3 = AgCl↓ + HNO3;
ДЕ
Silver
nitrate
Silver
chloride
Nitric
acid
МС
Ь
КИ
Й
b) 2HCl + Na2CO3 = 2NaCl + H2CO3
Sodium
carbonate
Sodium
chloride
Carbonic
acid
CO2↑
;
H2O
c) 2CH3COOH + Na2CO3 ⇔ 2CH3COONa + H2CO3
СУ
Acetic
acid
Sodium
carbonate
Sodium
acetate
Carbonic
acid
CO2
.
Н2О
7 Acids react with metals. The character of these reaction
products depends on the acid nature and its concentration and on
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
the metal activity. Metal activity is defined by its position in the
electrochemical series:
Li, K, Ba, Ca, Na, Mg, Al, Zn, Cr, Fe, Ni, Pb, H, Cu,
Ag, Hg, Pt, Au.
In this row the metal activity decreases from left to right.
Diluted sulphuric acid H2SO4, hydrochloric acid HCl and
others react with metals, which stand in the electrochemical
series to the left from hydrogen. In the result of the reaction a
salt and gaseous hydrogen are formed. For example:
a) H2SO4 + Zn = ZnSO4 + H2 ↑;
b) 2HCl + Mg = MgCl2 + H2 ↑.
The named acids do not react with metals standing to the
right from hydrogen in the electrochemical series. For example:
Ag + HCl ≠ .
Concentrated sulphuric acid H2SO4 and nitric acid HNO3
of any concentration are acids-oxidants and show special
properties in the reactions with metals, these dependences are
considered in Figures 2, 3.
РЖ
Ways of acids preparation
КИ
Й
ДЕ
1 Oxygenfree acids are prepared by means of synthesis from
simple substances and further solution in water of the product
obtained.
Hydrogenous
Non-metal + Н2 = non-metal
compound,
МС
Ь
where non-metals are: F2, Cl2, Br2, I2, S, Se.
H2 + Cl2 = 2HCl.
СУ
2 Oxoacids acids are formed by reaction of acid oxides with
water.
Т
Acid oxide + Н2О = Oxoacids acid:
ТЕ
SO3 + H2O = H2SO4.
ЕР
ІВ
Salt + Acid = Salt` + Acid``.
2NaCl + H2SO4 = Na2SO4 + 2HCl ↑,
Na2SiO3 + H2SO4 = H2SiO3 ↓ + Na2SO4.
СИ
3 Most acids can be formed by reaction of salts with acids.
Й
УН
This method is used for obtaining volatile acids and acids
difficult to dissolve.
НИ
QUIZ
КИ
Й
ДЕ
РЖ
АВ
1 What are the physical properties of acids?
2 How do acids turn the indicator colouring?
3 What is the neutralization reaction?
4 What acids react with oxides, bases, amphoteric hydroxides
and salts? Give examples.
5 How do acids react with metals? Give examples.
6 What ways of preparation of acids do you know? Write the
equations and name the acids formed.
PROBLEMS
СУ
МС
Ь
1 Which of the following metals does diluted sulphuric acid
react with: Al, Fe, Zn, Au, Mg, Hg, Cu, Ni?
Write the equations. Name the substance obtained.
2 Write the reaction equations of the following
transformations:
а) S −> SO2 −> SO3 −> H2SO4 −> BaSO4;
b) P −> P2O5 −> H3PO4;
c) N2O5 −> HNO3 −> Cu(NO3)2 −> Cu(OH)2 −> CuO.
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
3 Write the molecular equations of the reactions between:
а) hydrochloric acid and magnesium hydroxide;
b) nitric acid and potassium hydroxide;
c) nitric acid and zinc hydroxide;
d) sulphuric acid and copper (II) hydroxide;
e) nitric acid and chromium (III) hydroxide.
4 Which of the following substances will hydrochloric acid
react with: N2O5, Zn(OH)2, CaO, AgNO3, H3PO4, H2SO4?
Write the equations.
5 Which of the following substances will sulfurous acid react
with: К, Н2О, NaOH, Cu, BaO, CaCO3, Ca(OH)2? Write the
equations.
6 Which of the following substances will diluted
hydrochloric acid react with: KCl, KOH, K2SO4, BaSO4, Fe,
Fe2O3, Ag, Ag2O? Write the equations.
7 Which of the following substances will diluted sulfuric acid
react with: Mg, CaO, Ca(OH)2, CaCO3, Hg, Cu(OH)2? Write the
equations.
8 Which of the following substances will diluted sulfuric acid
react with: Al, Al2O3, Al(OH)3, Ba(NO3)2, Ag? Write the
equations.
ДЕ
10 AMPHOTERIC HYDROXIDES, THEIR
PROPERTIES
Й
Physical properties of amphoteric hydroxides
МС
Ь
КИ
All amphoteric hydroxides are solid substances, insoluble in
water. Most amphoteric hydroxides are of the white colour.
Chemical properties of amphoteric hydroxides
СУ
In a neutral medium (pure water) amphoteric hydroxides are
practically insoluble and do not dissociate into ions.
СИ
ТЕ
Т
They dissolve in acids and alkalis. Dissociation of amphoteric
hydroxides in acid and alkali mediums can be expressed by the
following equations:
H+
OH−
Zn2+ + 2OH− ⇔ Zn(OH)2 ⇔ 2H+ + ZnO22−,
ЕР
H+
OH−
Sn2+ + 2OH− ⇔ Sn(OH)2 ⇔ 2H+ + SnO22−,
ІВ
H+
OH−
Pb + 2OH ⇔ Pb(OH2) ⇔ 2H+ + PbO22−,
−
УН
2+
Й
H+
OH−
Al3+ + 3OH− ⇔ Al(OH)3 ⇔ H+ + AlO2− + H2O,
АВ
НИ
H+
OH−
Cr3+ + 3OH− ⇔ Cr(OH)3 ⇔ H+ + CrO2− + H2O.
Amphoteric hydroxides react both with acids and alkalis to
produce salt and water.
КИ
Й
ДЕ
РЖ
Reaction of amphoteric hydroxides with acids
Zn(OH)2 + 2HCl ⇔ ZnCl2 + 2H2O,
Sn(OH)2 + H2SO4 ⇔ SnSO4 + 2H2O,
Pb(OH)2 + 2HNO3 ⇔ Pb(NO3)2 + 2H2O,
Al(OH)3 + 3HCl ⇔ AlCl3 + 3H2O,
Cr(OH)3 + 3HNO3 = Cr(NO3)3 + 3H2O.
МС
Ь
Reaction of amphoteric hydroxides with alkalis
СУ
1 Alloying of amphoteric hydroxides with solid alkalis:
t0
Zn(OH)2 + 2NaOH = Na2ZnO2 + 2H2O;
Sodium
zincate
Т
t0
Al(OH)3 + NaOH = NaAlO2 + 2H2O или
ТЕ
Sodium
metaaluminate
СИ
t0
Al(OH)3 + 3NaOH = Na3AlO3 + 3H2O.
Sodium
orthoaluminate
ІВ
ЕР
2 Amphoteric hydroxides react with surplus of alkalis
solutions to make hydroxocomplex compounds:
Zn(OH)2 + 2NaOH = Na2[Zn(OH)4],
Sodium tetrahydroxozincate
УН
Sn(OH)2 + 2NaOH = Na2[Sn(OH)4],
Sodium tetrahydroxostannite
Pb(OH)2 + 2NaOH = Na2[Pb(OH)4].
Й
Sodium tetrahydroxoplumbite
АВ
НИ
Depending on the concentration of alkali solutions and the
reagents correlation aluminium hydroxide can form two
hydroxocomplexes:
Al(OH)3 + NaOH = Na[Al(OH)4],
Sodium tetrahydroxoaluminate
Al(OH)3 + 3NaOH = Na3[Al(OH)6].
QUIZ
ДЕ
РЖ
Sodium hexahydroxoaluminate
СУ
МС
Ь
КИ
Й
1 What are the physical properties of amphoteric hydroxides?
2 How do amphoteric hydroxides dissociate in acid and
alkaline media?
3 How do amphoteric hydroxides react with acids? Give
examples.
4 How do amphoteric hydroxides react with alkalis? Give
examples.
problems
1 Write the equation of obtaining zinc hydroxide out of zinc
oxide.
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
Т
2 Write the equations that show chromium (III) hydroxide
dissociation and the equations of its dissolving in:
а) nitric acid;
b) sodium hydroxide solution.
3 Which of the following substances does zinc hydroxide
react with: KCl, HNO3, KOH, KNO3, Al, H2O? Write the
equations.
4 Can the solutions, containing: AlCl3 and NaOH; Al2(SO4)2
and Ba(NO3)2 ; KAlO2 and HCl be prepared? Give reasons for
your answer. Write the equations.
5 Write the molecular and ionic equations of the following
transformations:
Al −> Al2O3 −> Al2(SO4)3 −> Al(OH)3 −>
−> KАlO2 −> Al(OH)3 −> Al2O3.
РЖ
АВ
11 SALTS, THEIR PROPERTIES AND WAYS OF
PREPARATION. GENETIC CONNECTION
BETWEEN THE MOST IMPORTANT CLASSES OF
INORGANIC COMPOUNDS
ДЕ
Physical properties of salts
СУ
МС
Ь
КИ
Й
Most salts are solid substances of the white colour: KNO3,
KCl, NaCl, BaSO4 and others.
Some salts have the colouring, for example: potassium
dichromate К2Cr2O7 is orange, potassium chromate K2CrO4 yellow, nickel (II) sulfate NiSO4 - green, cobalt (III) chloride
CoCl3 – pink, copper (II) sulfide CuS black.
According to their ability to dissolve in water salts are
divided into soluble in water (s), hardly soluble in water (h) and
insoluble (i).
Solubility of the most important salts in water is shown in
table 5.
Т
Chemical properties of salts
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
1 Soluble salts in water solutions dissociate into ions:
а) normal salts dissociate into metal cations and acid residual
anions:
KCl ⇔ K+ + Cl−,
NaCN ⇔ Na+ + CN−,
Ba(CH3COO)2 ⇔ Ba2+ + 2CH3COO−;
b) acid salts dissociate into metal cations and complex
anions:
KHSO4 ⇔ K+ + HSO4−,
NaH2PO4 ⇔ Na+ + H2PO4−,
Na2HPO4 ⇔ 2Na+ + HPO42−;
c) basic salts dissociate into complex cations and acid
residual anions:
AlOH(CH3COO)2 ⇔ AlOH2+ + 2CH3COO−,
Al(OH)2CH3COO ⇔ Al(OH)2+ + CH3COO−.
2 Salts react with metals to make a new salt and a new metal.
A given metal can displace another metal from a salt solution
provided it stands to the right from it in the electrochemical
series.
Ме (1) + Salt (1) = Ме (2) + Salt (2),
where Ме (1) is a more active metal than Ме (2).
For example, the reaction of copper (II) sulfate solution with
metallic iron produces metallic copper:
CuSO4 + Fe = FeSO4 + Cu.
СУ
МС
Ь
Iron displaces copper from copper salt solution, because iron
is a more active metal than copper.
3 Salts solutions react with alkalis to form a new salt and a
new insoluble base or a new insoluble salt.
Salt + Soluble base (alkali) = Salt + Base.
ТЕ
Potassium
chloride
K2CO3 + Ba(OH)2 = BaCO3 ↓ + 2KOH,
Barium
carbonate
Potassium
hydroxide
СИ
Iron
hydroxide
Т
For example:
FeCl3 + 3KOH = Fe(OH)3↓ + 3KCl,
ІВ
УН
Salt + Acid = Salt + Acid.
For example:
BaCl2 + H2SO4 = BaSO4 ↓ + 2HCl.
ЕР
4 Salts react with acids to produce a new weaker acid or a
new insoluble salt.
Й
Barium
sulfate
АВ
НИ
When salts react with acids forming the given salt, acid salts
are formed (it is possible if the salt was formed by a polybasic
acid). For example:
Na2S + H2S = 2NaHS,
Sodium
sulfide
Sodium
hydrosulfide
РЖ
CaCO3 + CO2 + H2O ⇔ Ca(HCO3)2.
Calcium
hydrocarbonate
ДЕ
Calcium
carbonate
КИ
Й
5 Salts can react between themselves to produce a new salt,
in case if one of the salts sedimentates.
SaltI + SaltII = SaltIII + SaltIV.
For example:
AgNO3 + KCl = AgCl↓ + KNO3.
МС
Ь
Silver
nitrate
Potassium Silver
chloride chloride
Potassium
nitrate
СУ
6 Some salts decompose when heated.
t0
Salt = Basic oxide + Acid oxide
ТЕ
Т
For example:
а) MgCO3 = MgO + CO2↑;
Magnesium
carbonate
ЕР
Calcium
hydrocarbonate
СИ
b) Са(НСО3)2 = СаО + 2СО2 ↑ + Н2О.
ІВ
7 Basic salts react with acids to produce normal salts and
water.
УН
Basic salt + Acid = Normal salt + Н2О.
For example:
Copper
chloride
НИ
Hydroxocopper
chloride
Й
CuOHCl + HCl = CuCl2 + H2O,
Fe(OH)2NO3 + HNO3 = FeOH(NO3)2 + H2O,
Hydroxoiron (III)
nitrate
АВ
Dihydroxoiron
nitrate
РЖ
FeOH(NO3)2 + HNO3 = Fe(NO3)3 + H2O.
Iron (III)
nitrate
Й
ДЕ
8 Acid salts react with soluble bases (alkalis) to form normal
salts and water.
Acid salts + Soluble base (alkali) = Normal salt + Н2О.
For example:
NaHSO3 + NaOH = Na2SO3 + H2O,
КИ
Sodium
hydrosulfite
Sodium
sulfite
KH2PO4 + KOH = K2HPO4 + H2O,
МС
Ь
Potassium
dihydrophosphate
Potassium
hydrophosphate
СУ
K2HPO4 + KOH = K3PO4 + H2O.
Potassium
phosphate
ТЕ
Т
Ways of salt preparation
ЕР
СИ
All the ways of salt preparation are based on the chemical
properties of the most important classes of inorganic
compounds.
The major ways of salt preparation are represented in table 6.
Table 6 − The major ways of salt preparation
Acid oxide
Acid
Salt
Metal
Salt (10)
−
Basic
oxide
Base
−
Salt + Metal
(9)
−
Salt
−
Salt
(4)
Salt + Water
(2)
−
Salt + …
(8)
Salt + Water
(3)
Salt + Water
(1)
Salt + Acid
(6)
УН
Й
НИ
АВ
−
ІВ
Nonmetal
Salt + Base
(5)
Salt + Salt
(7)
ДЕ
РЖ
10 major ways of salt preparation are shown in the following
examples.
1 Reaction of bases with acids.
Base + Acid = Salt + Water.
МС
Ь
КИ
Й
For example:
NaOH + HCl = NaCl + H2O,
Cu(OH)2 + H2SO4 = CuSO4 + 2H2O.
2 Reaction of bases with acid oxides.
Base + Acid oxide = Salt + Water.
СУ
For example:
Са(ОН)2 + СО2 = СаСО3 + Н2О,
2NH4OH + SO3 = (NH4)2SO4 + H2O.
3 Reaction of basic oxides with acids.
Т
Basic oxide + Acid = Salt + Water.
ІВ
УН
Basic oxide + Acid oxide = Salt.
For example:
СаО + СО2 = СаСО3,
ZnO + SO3 = ZnSO4.
ЕР
4 Reaction of basic oxides with acid oxides.
СИ
ТЕ
For example:
ВаО + H2SO4 = BaSO4 + H2O,
CuO + 2HNO3 = Cu(NO3)2 + H2O.
Й
5 Reaction of soluble bases (alkalis) with salts.
НИ
Basic salt
or
+ Salt.
insoluble base
АВ
Soluble base (alkali) + Salt =
ДЕ
РЖ
For example:
FeCl3 + NaOH = FeOHCl2 + NaCl,
FeCl3 + 2NaOH = Fe(OH)2Cl + 2NaCl,
FeCl3 + 3NaOH = Fe(OH)3↓ + 2NaCl.
КИ
Й
6 Reaction of salts with acids.
Salt + Acid = Salt + Acid.
For example:
AgNO3 + HCl = AgCl↓ + HNO3,
BaCl2 + H2SO4 = BaSO4 ↓ + 2HCl.
МС
Ь
7 Reaction of 2 salts.
СУ
SaltI + Salt II = SaltIII + SaltIV.
For example:
AgNO3 + NaCl = AgCl↓ + NaNO3,
Т
Na2CO3 + BaCl2 = BaCO3↓ + 2NaCl.
ТЕ
8 Reaction of metals with acids.
СИ
Ме + Acid = Salt + Н2 ↑.
9 Reaction of salts with metals.
УН
ІВ
ЕР
Hydrogen is evolved when metals react with all the acids,
except nitric acid HNO3 and concentrated sulfuric acid H2SO4.
For example:
Mg + H2SO3 = MgSO3 + H2 ↑,
Zn + 2HCl = ZnCl2 + H2 ↑.
НИ
Й
Salt + Ме (1) = Salt + Ме (2).
РЖ
АВ
Ме (1) must be a more active metal than Ме (2).
For example:
Cu + HgCl2 = CuCl2 + Hg,
Zn + Cu(NO3)2 = Zn(NO3)2 + Cu.
10 Reaction of metals with non-metals:
ДЕ
Ме + Non-Ме = Salt.
МС
Ь
КИ
Й
For example:
t0
Сu + Cl2 = CuCl2,
t0
F + S = FeS.
СУ
Except these ways of salt preparation some particular ways
are also possible.
1 Reaction of the metals, which oxides and hydroxides are
amphoteric, with soluble bases (alkalis).
ЕР
СИ
ТЕ
Т
Ме + Soluble base (alkali) = Salt + Н2 ↑.
For example:
Zn + 2NaOH = Na2ZnO2 + H2 ↑.
With water solutions of alkalis the reaction follows the
equation.
Zn + 2NaOH + 2H2O = Na2[Zn(OH)4] + H2↑.
ІВ
2 Alloying of salts with some acid oxides.
УН
Salt + Acid oxide = Salt + Acid oxide.
For example:
НИ
Й
t0
K2CO3 + SiO2 = K2SiO3 + CO2 ↑.
3 Reaction of soluble bases (alkalis) with halogens.
When cold
РЖ
АВ
Cl2 + 2KOH ======= KCl + KClO + H2O,
t0
3Cl2 + 6KOH = 5KCl + KClO3 + 3H2O.
ДЕ
4 Reaction of halogenides with halogens.
МС
Ь
КИ
Й
Salt + Hal2 (1) = Salt + Наl2 (2).
Hal2 (1) is more active than Hal2(2).
The oxidizing activity of halogens decreases in the row: F2,
Cl2, Br2, I2.
2KBr + Cl2 = 2KCl + Br2,
2NaI + Br2 = 2NaBr + I2.
СУ
Genetic connection between the main classes of inorganic
compounds
The connection between the classes of inorganic
compounds which is based on the preparation of
СИ
ТЕ
Т
one class substances from the other class substances
is called genetic.
Figure 4 – Genetic connection between the classes of
inorganic compounds
Non-metal
ЕР
Metal
+О2
ІВ
+О2
Acid oxide
УН
Basic oxide
+Н2О
Acid
НИ
Й
Base
+Н2О
РЖ
АВ
Salt
The model of solving a transformations chain
ДЕ
Write the molecular equations, with the help of which the
following transformations can be completed:
МС
Ь
КИ
Й
Fe −> Fe2O3 −> Fe2(SO4)3 −> Fe(OH)3 −>
−> FeOH(NO3)2 −> Fe(NO3)3.
Solving
СУ
1 Let’s obtain iron (III) oxide:
t0
2Fe + 3O2 = 2Fe2O3.
СИ
Fe2O3 + 3H2SO4 = Fe2(SO4)3 + 3H2O.
ТЕ
Т
2 Reacting upon iron (III) oxide with the sulphuric acid, we
obtain iron (III) sulphate:
ЕР
3 Iron (III) hydroxide Fe(OH)3 can be formed by addition of
an alkali solution to the salt solution:
ІВ
Fe2(SO4)3 + 6NaOH = 2Fe(OH)3 ↓ + 3Na2SO4.
Й
УН
4 In order to obtain the basic salt, we’ll influence upon
Fe(OH)3 by nitric acid taken in the quantity that is enough to
replace two hydroxide groups by acid residues, that is for one
mole of Fe(OH)3 − two moles of HNO3:
НИ
Fe(OH)3 + 2HNO3 = FeOH(NO3)2 + 2H2O.
РЖ
АВ
5 In order to obtain the normal salt we’ll add the necessary
quantity of an acid to the basic salt (for one mole of
FeOH(NO3)2 − one mole of HNO3):
ДЕ
FeOH(NO3)2 + HNO3 = Fe(NO3)3 + H2O.
QUiz
СУ
МС
Ь
КИ
Й
1 What physical properties of salts do you know?
2 How are salts divided according to their solubility in water?
3 How do normal salts dissociate in water?
4 How do acid salts dissociate in water?
5 How do basic salts dissociate in water?
6 How do salts react with metals? Give examples.
7 How do salts react with acids? Give examples.
8 How do salts react with other salts? Give examples.
9 What ways of salt preparation do you know?
10 What is called the genetic connection between the classes of
inorganic compounds?
Т
PROBLEMS
НИ
Й
УН
ІВ
ЕР
СИ
ТЕ
1 Write the equations between acids and bases to form the
following salts: Ni(NO3)2, K2S, NaHCO3, Na2HPO4.
2 Write the formula of basic iron (III) chlorides and the
equations of the transformations of these salts into a normal salt
– iron (III) chloride.
3 Write the equations of producing acid salts from sulfurous
acid and sodium and barium hydroxides.
4 Write the equations of forming the salts:
а) barium hydroxochloride;
b) iron (III) hydroxosulphate from the corresponding acids
and bases.
5 Write the molecular equations, with the help of which the
following transformations can be completed:
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
а) Са −> CaO −> Ca(OH)2 −> CaCO3 −> Ca(HCO3)2;
b) Zn −> ZnSO4 −> Zn(OH)2 −> ZnOHCl −> ZnCl2;
c) Al −> Al2(SO4)3 −> Al(OH)3 −> Al(OH)2Cl −> AlCl3;
d) Cu −> CuO −> Cu(NO3)2 −> Cu(OH)2 −> CuO;
Na2SO4 −> BaSO4
e)
Na −> NaOH
;
NaCl −> AgCl
f) S −> SO2 −> SO3 −> H2SO4 −> K2SO4 −> BaSO4;
g) Cu(NO3)2 −> CuOHNO3 −> Cu(OH)2 −> CuO −>
––> CuSO4;
h) P −> P2O5 −> H3PO4 −> NaH2PO4 −> Na2HPO4 ––>
−> Na3PO4;
12 GENERAL KNOWLEGDE ABOUT DOUBLE AND
COMPLEX SALTS (COORDINATION COMPOUNDS)
СУ
Except the considered above normal, acid and basic salts,
there also exist double and complex salts. For example: double
СИ
ТЕ
Т
salts − KАl(SO4)2, NH4Fe(SO4)2; complex salts (coordinnation
compounds) − [Cu(NH3)4]SO4, K3[Fe(CN)6], Na3[Al(OH)6].
Such salts are formed when neutral molecules of different
substances join each other:
УН
ІВ
ЕР
K2SO4 + Al2(SO4)3 = K2SO4 ⋅ Al2(SO4)3 = 2KАl(SO4)2,
(NH4)2SO4 + Fe2(SO4)3 = (NH4)2SO4⋅Fe2(SO4)3 =
= 2NH4Fe(SO4)2,
CuSO4 + 4NH3 = [Cu(NH3)4]SO4,
3KCN + Fe(CN)3 = K3[Fe(CN)6],
Al(OH)3 + 3NaOH = Na3[Al(OH)6].
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
Double salts differ from complex salts in the character of
their dissociation in water solutions. Double salts dissociate (in
one stage) into cations of both metals (or an ammonium cation)
and anions of the acid residue:
KAl(SO4)2 ⇔ K+ + Al3+ + 2SO42−,
NH4Fe(SO4)2 ⇔ NH4+ + Fe3+ + 2SO42−.
Complex salts when dissociating form complex ions, that are
rather steady in water solutions:
[Cu(NH3)4]SO4 ⇔ [Cu(NH3)4]2+ + SO42−,
K3[Fe(CN)6] ⇔ 3K+ + [Fe(CN)6]3−.
The theory of complex compound structure was worked out
by the Swiss chemist A.Werner.
According to A.Werner’s theory, in the centre of a molecule
of a coordination compound the central metal ion is situated.
The most inclination for complexing show d-element ions.
Round the central metal ion there are oppositely charged ions or
neutral molecules, called ligands, or addends (table 7).
СУ
Table 7 − Types of coordination compounds
Ligand
Name of the
coordination
compound
Examples
Hydroxo-ions ОН−
Anios of the acid
residues: CN−,NO2−,
Cl−, I−, Br− and others.
Neutral molecules:
NH3, H2O
Na2[Zn(OH)4]
K4[Fe(CN)6]
K2[HgI4]
Na3[Co(NO2)6]
[Ag(NH3)2]Cl
[Al(H2O)6]Cl3
ТЕ
Т
Hydroxocomplexes
Acidocomplexes
СИ
Ammines
Aquacomplexes
АВ
Central metal ion
Cu+, Ag+, Au+
Cu2+, Co2+, Au3+, Zn2+, Pb2+, Pt2+, Al3+
Fe2+, Fe3+, Co3+, Ni2+, Al3+, Pt4+, Pb4+, Cr3+
РЖ
Coordination
2
4
6
НИ
Й
УН
ІВ
ЕР
The combination of a central metal ion and its ligands is
called a complex ion, and a neutral compound containing
complex ions is called a coordination compound.
An complex ion make the inner sphere of a coordination
compound, denoted by square brackets. The number of ligands
(addends), which coordinate around the central metal ion, is
called the coordination number. The most characteristic
coordination numbers for the ions of different metals are given
below:
КИ
Й
ДЕ
The charge of the complex ion is equal to the algebraic
sum of the charges of the central metal ion and
ligands. If the ligands are electrically neutral
molecules, the charge of the complex ion is equal to the
charge of the central metal ion.
Complex
ion-anion
[Cu+2(NH3)04]2+
[Fe+2(CN)–6]4−
[Co+3(NH3)03Cl–3]0
[Al+3(OH)–6]3−
[Pt+2(NH3)04Br–2]0.
СУ
МС
Ь
Complex
ion-cation
[Co+3Br–(NH3)05]2+
Complex
neutral molecule
ТЕ
Т
The ions not entering the inner sphere, form the outer
sphere. If a complex ion is a cation, there are anions in the outer
sphere:
СИ
[Cu(NH4)4]2+SO42−, [Ag(NH3)2]1+Cl−.
NH4[AuCl4].
УН
K4[Fe(CN)6] Na[Ag(CN)2]
ІВ
ЕР
If a complex ion is an anion, there are cations in the outer
sphere. Cations are usually the cations of alkaline and alkalineearth metals and an ammonium cation:
Commplex ion (inner sphere)
Coordination
number
Ligands
АВ
Outer
sphere
НИ
Й
K4 [Fe(CN)6]
РЖ
Central metal ion
A coordination compound
ДЕ
Names of some salts
МС
Ь
КИ
Й
К3[Fe(CN)6] − potassium hexacianoferrate (III),
K4[Fe(CN)6] − potassium hexacianoferrate (II),
[Cu(NH3)4]SO4 − tetraamminecopper (II) sulphate,
[Ag(NH3)2]Cl − diamminesilver (I) chloride.
The importance of complex compounds
СУ
In living beings complex compounds have specific functions
in metabolism. Natural complex compounds play an important
role in the processes of photosynthesis, biological oxidation,
breathing and in the fermentative catalysis.
СИ
ТЕ
Т
For example, chlorophyll, promoting photosynthesis process
in plants, is a complex compound containing magnesium, and
haemoglobin, providing the cells of a living being with oxygen,
is an iron complex. Vitamin В12 − is a complex compound
containing cobalt.
ЕР
The model of solving a typical problem
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
Й
УН
ІВ
Define the charge of the complex ion, oxidation state and the
coordination number of the central metal ion in the compounds:
а) К2[PtCl4]; b) [Ag(NH3)2]Cl.
A charge of a complex ion is equal to the algebraic sum of
the charges of its central metal ion and ligands. A charge of a
central metal ion is considered to be equal to its oxidation state.
A molecule of the complex compound is electrically neutral.
a) K2[PtCl4] − Pt − a central metal ion , Cl− − a ligand, there
are four ligands, so the coordination number (c.n.)=4.
A potassium ion has the charge 1+ (К1+). The compound
contains 2 potassium ions, so the charge of the complex ion is
equal to -2 – ([PtCl4]2–). The charge of the central ion is equal
to the difference between the complex ion charges and the sum
of the ligands charges. A ligand Cl has the charge -1 (Cl–).
The sum of the ligand charges: 4⋅ (–1) = –4.
The charge of the central metal ion: –2 – (–4) = –2 + 4 =2.
The oxidation state of Pt = 2.
b) [Ag(NH3)2 ]Cl c.n. = 2.
The charge of the ion Cl = –1 ( Cl–).
The charge of the complex ion = +1 ([Ag(NH3)2]+.
The charge of the ligand = 0 (NH3)0.
The charge of the central metal ion = 1 – 0 = 1.
The oxidation state of Ag = +1 (Ag+1).
QUIZ
1 How are double salts and complex compounds formed?
2 How do complex compounds differ from double salts?
УН
ІВ
ЕР
СИ
ТЕ
Т
3 How do complex compounds and double salts dissociate in
water solutions? Give examples.
4 What is an central metal ion ? What ions can play the role
of complexing?
5 What are ligands (addends)? Give examples.
6 How are complex compounds classified? Explain it on the
examples.
7 What is coordination number? What ions have the
coordination numbers 2, 4, 6? Give examples.
8 How can the charge of a complex ion be calculated?
Explain it on the examples.
9 What is the importance of complex compounds?
Й
problems
СУ
МС
Ь
КИ
Й
ДЕ
РЖ
АВ
НИ
1 What type of salts do the following substances belong to:
K3[Fe(CN)6], (NH4)2SO4⋅FeSO4, K4[Fe(CN)6? What is the
oxidation state of iron in these compounds?
2 Define the oxidation state of a central metal ion in the
following complex ions: [Ni(NH3)5Cl]+, [Co(NH3)2(NO2)4]−,
[Cr(H2O)4Br2]+, [AuCl4]−, [Hg(CN)4]2−, [Ag(S2O3)2]3−.
3 Define the number and the sign (+/-) of the charge of a
complex ion and the coordination number of a complexing in
the compounds: K[AlCl4], H3[AlF6], H[BF4], [PtCl(NH3)5]Cl,
[Co(H2O)6](NO2)3.
4 What are the oxidation state and the coordination number
of a complexing in the compounds: K3[Co(NO2)6],
[Co(NH3)5Cl]Cl2, [Co(NH3)5Br]SO4? How do these complex
compounds dissociate in water solutions?
5 What are the oxidation state and the coordination number in
the following compounds: [Cu(NH3)4] SO4, K2[PtCl6],
K[Ag(CN)2]? Write the dissociation equations of these complex
compounds.
6 Write the molecular equation of the exchange reactions
between Na3[Co(CN)6] and FeSO4, taking into account that the
formed complex salt is insoluble in water.