Form of salt in chemistry. Acid salts. Acidic salt solutions

Salts are chemical compounds in which a metal atom is bonded to an acidic residue. The difference between salts and other compounds is that they have a pronounced ionic nature of the bond. Therefore, the bond is called so - ionic. The ionic bond is characterized by unsaturation and non-directionality. Examples of salts: sodium chloride or kitchen salt - NaCl, calcium sulfate or gypsum - CaSO4. Depending on how completely the hydrogen atoms in the acid or the hydroxo groups in the hydroxide are replaced, medium, acidic and basic salts are distinguished. The salt may contain several metal cations - these are double salts.

Medium salts

Medium salts are salts in which complete replacement of hydrogen atoms with metal ions occurs. Table salt and gypsum are such salts. Medium salts cover a large number of compounds that are often found in nature, for example, blende - ZnS, pyrrite - FeS2, etc. This type of salt is the most common.

Average salts are obtained by a neutralization reaction, when the base is taken in equimolar ratios, for example:
H2SO3 + 2 NaOH = Na2SO3 + 2 H2O
It turns out medium salt. If you take 1 mol of sodium hydroxide, then the reaction will proceed as follows:
H2SO3 + NaOH = NaHSO3 + H2O
It turns out the acidic salt of sodium hydrosulfite.

Acidic salts

Acid salts are salts in which not all hydrogen atoms are replaced by a metal. Such salts are capable of forming only polybasic acids - sulfuric, phosphoric, sulfurous and others. Monobasic acids such as hydrochloric, nitric and others do not give.
Examples of acidic salts: sodium bicarbonate or baking soda - NaHCO3, sodium dihydrogen phosphate - NaH2PO4.

Acid salts can also be obtained by reacting medium salts with an acid:
Na2SO3 + H2SO3 = 2NaHSO3

Basic salts

Basic salts are salts in which not all hydroxo groups are substituted with acidic residues. For example, aluminum hydroxosulfate - Al (OH) SO4, zinc hydroxochloride - Zn (OH) Cl, copper dihydroxocarbonate or malachite - Cu2 (CO3) (OH) 2.

Double salts

Double salts are salts in which two metals replace hydrogen atoms in the acid residue. Such salts are possible for polybasic acids. Examples of salts: sodium potassium carbonate - NaKCO3, potassium aluminum sulfate - KAl (SO4) 2 .. The most common double salts in everyday life are alum, for example, potassium alum - KAl (SO4) 2 12H2O. They are used for water purification, leather tanning, and dough loosening.

Mixed salts

Mixed salts are salts in which a metal atom is bonded to two different acidic residues, for example, bleach - Ca (OCl) Cl.

In the previous sections, we have encountered reactions in which salts are formed.

Salts are substances in which metal atoms are bonded to acidic residues.

An exception are ammonium salts, in which not metal atoms, but NH 4 + particles are bound to acid residues. Examples of typical salts are shown below.

NaCl - sodium chloride,

Na 2 SO 4 - sodium sulfate,

CaSO 4 - calcium sulfate,

CaCl 2 - calcium chloride,

(NH 4) 2 SO 4 - ammonium sulfate.

The salt formula is built taking into account the valences of the metal and the acid residue. Almost all salts are ionic compounds, so we can say that metal ions and ions of acid residues are connected in salts:

Na + Cl - - sodium chloride

Ca 2+ SO 4 2– - calcium sulfate, etc.

The names of the salts are formed from the name of the acid residue and the name of the metal. The main thing in the name is the acid residue. The names of the salts depending on the acid residue are shown in Table 4.6. In the upper part of the table, oxygen-containing acidic residues are given, in the lower part - anoxic residues.

Table 4-6. Construction of the names of salts.

From table 4-6 it can be seen that the names of oxygen-containing salts have the endings " at", And the names of anoxic salts - the endings" id».

In some cases, the ending “ it". For example, Na 2 SO 3 - sulfite sodium. This is done in order to distinguish between the salts of sulfuric acid (H 2 SO 4) and sulfurous acid (H 2 SO 3) and in other similar cases.

All salts are divided into medium, sour and the main. Average salts contain only metal atoms and an acidic residue. For example, all salts from Table 4-6 are average salts.

Any salt can be obtained by an appropriate neutralization reaction. For example, sodium sulfite is formed in the reaction between sulfurous acid and a base (sodium hydroxide). In this case, for 1 mol of acid, it is required to take 2 mol of a base:

If we take only 1 mol of base - that is, less than is required for complete neutralization, it is formed sour salt - sodium hydrosulfite:

Acidic salts are formed by polybasic acids. Monobasic acids do not form acidic salts.

Acid salts, in addition to metal ions and acid residue, contain hydrogen ions.

The names of acidic salts contain the prefix "hydro" (from the word hydrogenium - hydrogen). For example:

NaHCO 3 - sodium bicarbonate,

K 2 HPO 4 - potassium hydrogen phosphate,

KH 2 PO 4 - potassium dihydrogen phosphate.

The main salts are formed when the base is incompletely neutralized. Basic salts are named with the prefix "hydroxo". Below is an example showing the difference between basic salts and common (medium) salts.

>> Chemistry: Salts, their classification and properties

Of all chemical compounds salts are the most abundant class of substances. These are solids, they differ from each other in color and solubility in water.

Salt is a class of chemical compounds consisting of metal ions and acid residue ions.

At the beginning of the XIX century. Swedish chemist I. Verzelius formulated the definition of salts as products of reactions of acids with bases, or compounds obtained by replacing hydrogen atoms in an acid with a metal. On this basis, salts are distinguished between medium, acidic and basic.

Average, or normal, are products of complete replacement of hydrogen atoms in an acid with a metal.

It is with these salts that you are already familiar and know their nomenclature. For example:

Na2CO3 - sodium carbonate, CuSO4 - copper (II) sulfate, etc.

Such salts dissociate into metal cations and acid residue anions:

Acidic salts are products of incomplete replacement of hydrogen atoms in an acid with a metal.

Acidic salts include, for example, baking soda, which consists of a metal cation and an acidic singly charged residue HCO3. For acidic calcium salt, the formula is written as follows: Ca (HCO3) 2.

The names of these salts are made up of the names of the salts with the addition of the word hydro, for example:

Basic salts are products of incomplete substitution of hydroxo groups in the base by an acid residue.

For example, such salts include the famous malachite (SiON) 2 CO3, which you read about in I. Bazhov's tales. It consists of two basic cations CuOH and a doubly charged anion of the acidic residue CO 2 - 3.

The СuОН + cation has a charge of +1, therefore, in the molecule, two such cations and one doubly charged CO anion are combined into an electrically neutral salt.

The names of such salts will be the same as for normal salts, but with the addition of the word hydroxo, for example (CuOH) 2 CO3 - copper (II) hydroxycarbonate or AlOHCl2 - aluminum hydroxychloride. The vast majority of basic salts are insoluble or slightly soluble. The latter dissociate as follows:

Typical salt reactions

4. Salt + metal -> other salt + other metal.

The first two exchange reactions have already been discussed in detail earlier.

The third reaction is also an exchange reaction. It flows between salt solutions and is accompanied by the formation of a donkey, for example:

The fourth reaction of salts is associated with the name of the largest Russian chemist N.N. Beketov, who in 1865 studied the ability of metals to displace other metals from salt solutions. For example, copper tu of solutions of its salts can be displaced by such metals as magnesium, aluminum Al, zinc and other metals. But copper is not displaced by mercury, silver Ag, gold Au, since atm metals in the series of voltages are located to the right than copper. But copper displaces them from salt solutions:

H. Beketov, acting with gaseous hydrogen under pressure on solutions of mercury and silver salts, found that when the hydrogen atom, like some other metals, displaces mercury and silver from their salts.

Arranging metals, I also hydrogen according to their ability to displace each other and salt solutions. Beketov made a number. which he called the erosional series of metals. Later (1802, V. Nerist) it was proved that the displacement series of Veketov practically coincides with the series in which metals and hydrogen are located (to the right) in the order of decreasing their recovery capacity and the molar concentration of metal ions, equal to 1 mol / l. This series is called the electrochemical series of metal stresses. You already got acquainted with this series when you considered the interaction of acids with metals and found out that metals that are located to the left of hydrogen interact with acid solutions. This is the first application of a number of voltages. It is fulfilled subject to a number of conditions that we spoke about earlier.

The second rule of a series of stresses is as follows: each metal displaces from salt solutions all other metals located to the right of it in the series of stresses. This rule is also observed when the following conditions are met:

a) both salts (both reacting and resulting from the reaction) must be soluble;
b) metals do not have to react with water, therefore the metals of the main subgroups of groups I and II (for the latter, starting with Ca) do not displace other metals on salt solutions.

1. Salt medium (normal), acidic and basic.

2. Dissociation of various salt groups.

3. Typical properties of normal salts: their interaction with acids, alkalis, other salts and metals.

4. Two rules for a number of stresses in metals.

5. Conditions for the reactions of salts with metals.

Complete the molecular equations of possible reactions in solutions, and write down the corresponding ionic equations:

If the reaction cannot be carried out, explain why.

An excess of barium nitrate solution was added to 980 g of a 5% solution of weed acid. Find the mass of the precipitated sediment.

Write down the reaction equations for all possible methods for obtaining iron (II) sulfate.

Give the names of the salts.

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Salts are the products of the replacement of hydrogen of an acid with a metal or of hydroxyl groups of bases with acid residues.

For example,

H 2 SO 4 + Zn = ZnSO 4 + H 2

acid salt

NaOH + HC1 = NaCl + H 2 O

base acid salt

From the standpoint of the theory of electrolytic dissociation, Salts are electrolytes, the dissociation of which produces cations other than hydrogen cations and anions other than OH - anions.

Classification. Salts are medium, acidic, basic, double, complex.

Medium salt - it is the product of complete substitution of a metal for the hydrogen of an acid or of the hydroxyl group of a base with an acid residue. For example, Na 2 SO 4, Ca (NO 3) 2 are medium salts.

Sour salt - the product of incomplete substitution of hydrogen for a polybasic acid by a metal. For example, NaHSO 4, Ca (HCO 3) 2 are acidic salts.

Basic salt - the product of incomplete substitution of hydroxyl groups of a multi-acid base with acid residues. For example, Mg (OH) C1, Bi (OH) Cl 2 - basic salts

If the hydrogen atoms in the acid are replaced by atoms of different metals or the hydroxo groups of the bases are replaced by different acid residues, then double salt. For example, KAl (SO 4) 2, Ca (OC1) C1. Double salts exist only in the solid state.

Complex salts - these are salts containing complex ions. For example, the K 4 salt is complex, since it contains the complex ion 4-.

Formulation of salt formulas. We can say that salts are composed of base residues and acid residues. When drawing up salt formulas, you need to remember the rule: the absolute value of the product of the charge of the remainder of the base by the number of base residues is equal to the absolute value of the product of the charge of the acid residue by the number of acid residues. For tx = ny, where K- the remainder of the base, A- acid residue, T - charge of the remainder of the base, n- the charge of the acid residue, NS - number of base residues, y - number of acid residues. For example,

Salt nomenclature... Salt names are made up of

the names of the anion (acid residue (Table 15)) in the nominative case and the name of the cation (the base residue (Table 17)) in the genitive case (without the word "ion").

For the name of the cation, the Russian name of the corresponding metal or group of atoms is used (in brackets, Roman numerals indicate the oxidation state of the metal, if necessary).

Anions of anoxic acids are named using the ending –Id(NH 4 F - ammonium fluoride, SnS - tin (II) sulfide, NaCN - sodium cyanide). The endings of the names of the anions of oxygen-containing acids depend on the oxidation state of the acid-forming element:

The names of acidic and basic salts are formed by the same general rules as the names of the medium salts. In this case, the name of the acid salt anion is supplied with the prefix hydro- indicating the presence of unsubstituted hydrogen atoms (the number of hydrogen atoms is indicated by Greek numerals). The basic salt cation gets the prefix hydroxy indicating the presence of unsubstituted hydroxyl groups.

For example,

MgС1 2 - magnesium chloride

Ba 3 (PO 4) 2 - barium orthophosphate

Na 2 S - sodium sulfide

CaHPO 4 - calcium hydrogen phosphate

K 2 SO 3 - potassium sulfite

Ca (H 2 PO 4) 2 - calcium dihydrogen phosphate

A1 2 (SO 4) 3 - aluminum sulfate

Mg (OH) Cl - hydroxomagnesium chloride

KA1 (SO 4) 2 - potassium aluminum sulfate

(MgOH) 2 SO 4 - hydroxomagnesium sulfate

KNaHPO 4 - potassium sodium hydrogen phosphate

MnCl 2 - manganese (II) chloride

Ca (OCI) C1 - calcium chloride-hypochlorite

MnSO 4 - manganese (II) sulfate

K 2 S - potassium sulfide

NaHCO 3 - sodium bicarbonate

K 2 SO 4 - potassium sulfate

Salts are electrolytes that dissociate into aqueous solutions with the formation of necessarily a metal cation and an anion of an acid residue
The classification of salts is given in table. nine.

When writing formulas for any salts, one must be guided by one rule: the total charges of cations and anions must be equal in absolute value. Based on this, indices should be placed. For example, when writing the formula for aluminum nitrate, we take into account that the charge of the aluminum cation is +3, and that of the pitrate ion is 1: AlNO 3 (+3), and using the indices we equalize the charges (the least common multiple for 3 and 1 is 3. Divide 3 by the absolute value of the charge of the aluminum cation - we get the index Divide 3 by the absolute value of the charge of the anion NO 3 - we get the index 3). Formula: Al (NO 3) 3

Salt it

Average, or normal, salts contain only metal cations and acid residue anions. Their names are derived from the Latin name of the element that forms the acid residue, by adding the appropriate ending depending on the oxidation state of this atom. For example, the sulfuric acid salt Na 2 SO 4 is called (sulfur oxidation state +6), Na 2 S salt - (sulfur oxidation state -2), etc. In the table. 10 shows the names of the salts formed by the most commonly used acids.

The names of the medium salts underlie all the other salt groups.

■ 106 Write the formulas for the following average salts: a) calcium sulfate; b) magnesium nitrate; c) aluminum chloride; d) zinc sulfide; e); f) potassium carbonate; g) calcium silicate; h) iron (III) phosphate.

Acid salts differ from the average ones in that, in addition to the metal cation, they contain a hydrogen cation, for example, NaHCO3 or Ca (H2PO4) 2. An acid salt can be thought of as a product of incomplete substitution of a metal for hydrogen atoms in an acid. Therefore, acidic salts can only be formed with two or more basic acids.
The acid salt molecule usually contains an "acidic" ion, the charge of which depends on the degree of acid dissociation. For example, the dissociation of phosphoric acid proceeds in three stages:

At the first stage of dissociation, a singly charged Н 2 РО 4 anion is formed. Therefore, depending on the charge of the metal cation, the salt formulas will look like NaH 2 PО 4, Ca (Н 2 РО 4) 2, Ва (Н 2 РО 4) 2, etc. At the second stage of dissociation, a doubly charged HPO anion is formed 2 4 -. The salt formulas will look like this: Na 2 HPO 4, CaHPO 4, etc. The third stage of dissociation of acidic salts does not.
The names of acidic salts are derived from the names of the average ones with the addition of the prefix hydro- (from the word "hydrogenium" -):
NaHCO 3 - sodium bicarbonate KHSO 4 - potassium hydrogen sulfate CaHPO 4 - calcium hydrogen phosphate
If the acidic ion contains two hydrogen atoms, for example H 2 PO 4 -, the prefix di- (two) is added to the name of the salt: NaH 2 PO 4 - sodium dihydrogen phosphate, Ca (H 2 PO 4) 2 - calcium dihydrogen phosphate, etc. .d.

■ 107. Write the formulas of the following acidic salts: a) calcium hydrogen sulfate; b) magnesium dihydrogen phosphate; c) aluminum hydrogen phosphate; d) barium bicarbonate; e) sodium hydrogen sulfite; f) magnesium hydrosulfite.
108. Is it possible to obtain acidic salts of hydrochloric and nitric acids. Justify your answer.

All salts

Basic salts differ from the others in that, in addition to the metal cation and the acid residue anion, they contain hydroxyl anions, for example, Al (OH) (NO3) 2. Here the charge of the aluminum cation is +3, and the charges of the hydroxyl ion-1 and two nitrate ions are 2, in total - 3.
The names of the basic salts are formed from the names of the average ones with the addition of the word basic, for example: Сu 2 (OH) 2 СO 3 - basic copper carbonate, Al (OH) 2 NO 3 - basic aluminum nitrate.

■ 109. Write the formulas of the following basic salts: a) basic iron (II) chloride; b) basic iron (III) sulfate; c) basic copper (II) nitrate; d) basic calcium chloride; e) basic magnesium chloride; f) basic iron (III) sulfate g) basic aluminum chloride.

Formulas of double salts, for example KAl (SO4) 3, are constructed based on the total charges of both metal cations and the total charge of the anion

The total charge of the cations is + 4, the total charge of the anions is -4.
The names of double salts are formed in the same way as the middle ones, only the names of both metals are indicated: KAl (SO4) 2 - potassium-aluminum sulfate.

■ 110. Write the formulas for the following salts:
a) magnesium phosphate; b) magnesium hydrogen phosphate; c) lead sulfate; d) barium hydrogen sulfate; e) barium hydrosulfite; f) potassium silicate; g) aluminum nitrate; h) copper (II) chloride; i) iron (III) carbonate; j) calcium nitrate; l) potassium carbonate.

Chemical properties of salts

1. All medium salts are strong electrolytes and readily dissociate:
Na 2 SO 4 ⇄ 2Na + + SO 2 4 -
Medium salts can interact with metals that stand a number of voltages to the left of the metal that is part of the salt:
Fe + CuSO 4 = Cu + FeSO 4
Fe + Cu 2+ + SO 2 4 - = Cu + Fe 2+ + SO 2 4 -
Fe + Cu 2+ = Cu + Fe 2+
2. Salts react with alkalis and acids according to the rules described in the Bases and Acids sections:
FeCl 3 + 3NaOH = Fe (OH) 3 ↓ + 3NaCl
Fe 3+ + 3Cl - + 3Na + + 3ОН - = Fe (OH) 3 + 3Na + + 3Cl -
Fe 3+ + 3OH - = Fe (OH) 3
Na 2 SO 3 + 2HCl = 2NaCl + H 2 SO 3
2Na + + SO 2 3 - + 2H + + 2Cl - = 2Na + + 2Cl - + SO 2 + H 2 O
2H + + SO 2 3 - = SO 2 + H 2 O
3. Salts can interact with each other, resulting in the formation of new salts:
AgNO 3 + NaCl = NaNO 3 + AgCl
Ag + + NO 3 - + Na + + Cl - = Na + + NO 3 - + AgCl
Ag + + Cl - = AgCl
Since these exchange reactions are carried out mainly in aqueous solutions, they proceed only when one of the formed salts precipitates.
All exchange reactions proceed in accordance with the reaction conditions to the end listed in § 23, p. 89.

■ 111. Make the equations of the following reactions and, using the table of solubility, determine whether they will go to the end:
a) barium chloride +;
b) aluminum chloride +;
c) sodium phosphate + calcium nitrate;
d) magnesium chloride + potassium sulfate;
e) + lead nitrate;
f) potassium carbonate + manganese sulfate;
g) + potassium sulfate.
Write equations in molecular and ionic forms.

■ 112. With which of the following substances will iron (II) chloride react: a); b) calcium carbonate; c) sodium hydroxide; d) silicic anhydride; e); f) copper (II) hydroxide; g)?

113. Describe the properties of calcium carbonate as a medium salt. Write all equations in molecular and ionic forms.
114. How to carry out a number of transformations:

Write all equations in molecular and ionic forms.
115. What amount of salt will be obtained by the reaction of 8 g of sulfur and 18 g of zinc?
116. What volume of hydrogen will be released during the interaction of 7 g of iron with 20 g of sulfuric acid?
117. How many moles table salt will result from the reaction of 120 g of sodium hydroxide and 120 g of hydrochloric acid?
118. How much potassium nitrate will be obtained by the reaction of 2 moles of caustic potassium and 130 g of nitric acid?

Hydrolysis of salts

A specific property of salts is their ability to hydrolyze - to undergo hydrolysis (from the Greek "hydro" - water, "lysis" - decomposition), that is, decomposition under the action of water. It is impossible to regard hydrolysis as decomposition in the sense in which we usually understand it, but one thing is certain - it always participates in the hydrolysis reaction.
- very weak electrolyte, dissociates poorly
H 2 O ⇄ H + + OH -
and does not change the color of the indicator. Alkalis and acids change the color of the indicators, since when they dissociate in the solution, an excess of OH - ions (in the case of alkalis) and H + ions in the case of acids are formed. In salts such as NaCl, K 2 SO 4, which are formed strong acid(НСl, H 2 SO 4) and a strong base (NaOH, KOH), the color indicators do not change, since in a solution of these
salts, hydrolysis practically does not occur.
In the hydrolysis of salts, four cases are possible, depending on whether the salt is formed with a strong or weak acid and base.
1. If we take a salt of a strong base and a weak acid, for example K 2 S, the following happens. Potassium sulfide dissociates into ions as strong electrolyte:
K 2 S ⇄ 2K + + S 2-
Along with this, it weakly dissociates:
H 2 O ⇄ H + + OH -
Sulfur anion S 2- is a weak anion hydrogen sulfide acid which dissociates badly. This leads to the fact that the S 2- anion begins to attach hydrogen cations from water to itself, gradually forming low-dissociating groups:
S 2- + H + + OH - = HS - + OH -
HS - + H + + OH - = H 2 S + OH -
Since H + cations from water bind, and OH anions remain, the reaction of the medium becomes alkaline. Thus, during the hydrolysis of salts formed by a strong base and a weak acid, the reaction of the medium is always alkaline.

■ 119. Explain the process of hydrolysis of sodium carbonate using ionic equations.

2. If a salt is taken, formed by a weak base and a strong acid, for example Fe (NO 3) 3, then ions are formed during its dissociation:
Fe (NO 3) 3 ⇄ Fe 3+ + 3NO 3 -
The Fe3 + cation is a weak base cation - iron, which dissociates very poorly. This leads to the fact that the Fe 3+ cation begins to attach OH - anions from water to itself, forming low-dissociating groups:
Fe 3+ + H + + OH - = Fe (OH) 2+ + + H +
and further
Fe (OH) 2+ + H + + OH - = Fe (OH) 2 + + H +
Finally, the process can reach its last stage:
Fe (OH) 2 + + H + + OH - = Fe (OH) 3 + H +
Consequently, there will be an excess of hydrogen cations in the solution.
Thus, during the hydrolysis of a salt formed by a weak base and a strong acid, the reaction of the medium is always acidic.

■ 120. Explain with the help of ionic equations the course of hydrolysis of aluminum chloride.

3. If the salt is formed by a strong base and a strong acid, then neither the cation nor the anion binds water ions and the reaction remains neutral. Virtually no hydrolysis occurs.
4. If the salt is formed by a weak base and a weak acid, then the reaction of the medium depends on their degree of dissociation. If the base and acid are practically the same, then the reaction of the medium will be neutral.

■ 121. It is often necessary to see how, during the exchange reaction, instead of the expected salt precipitate, a metal precipitate is formed, for example, the reaction between iron (III) chloride FeCl 3 and sodium carbonate Na 2 CO 3 does not form Fe 2 (CO 3) 3, but Fe ( OH) 3. Explain this phenomenon.
122. Among the salts listed below, indicate those that undergo hydrolysis in the solution: KNO 3, Cr 2 (SO 4) 3, Al 2 (CO 3) 3, CaCl 2, K 2 SiO 3, Al 2 (SO 3) 3.

Features of the properties of acidic salts

Acid salts have slightly different properties. They can react with the preservation and destruction of the acidic ion. For example, the reaction of an acidic salt with an alkali leads to the neutralization of the acidic salt and the destruction of the acidic ion, for example:
NaHSO4 + KOH = KNaSO4 + H2O
double salt
Na + + HSO 4 - + K + + OH - = K + + Na + + SO 2 4 - + H2O
HSO 4 - + OH - = SO 2 4 - + H2O
The destruction of an acidic ion can be represented as follows:
HSO 4 - ⇄ H + + SO 4 2-
H + + SO 2 4 - + OH - = SO 2 4 - + H2O
The acidic ion is also destroyed by reaction with acids:
Mg (HCO3) 2 + 2HCl = MgCl2 + 2H2Co3
Mg 2+ + 2HCO 3 - + 2Н + + 2Сl - = Mg 2+ + 2Сl - + 2Н2O + 2СO2
2HCO 3 - + 2H + = 2H2O + 2CO2
HCO 3 - + H + = H2O + CO2
Neutralization can be carried out with the same alkali that formed the salt:
NaHSO4 + NaOH = Na2SO4 + H2O
Na + + HSO 4 - + Na + + OH - = 2Na + + SO 4 2- + H2O
HSO 4 - + OH - = SO 4 2- + H2O
Reactions with salts proceed without destroying the acidic ion:
Ca (HCO3) 2 + Na2CO3 = CaCO3 + 2NaHCO3
Ca 2+ + 2HCO 3 - + 2Na + + CO 2 3 - = CaCO3 ↓ + 2Na + + 2HCO 3 -
Ca 2+ + CO 2 3 - = CaCO3
■ 123. Write in molecular and ionic forms the equations of the following reactions:
a) potassium hydrosulfide +;
b) sodium hydrogen phosphate + potassium hydroxide;
c) calcium dihydrogen phosphate + sodium carbonate;
d) barium bicarbonate + potassium sulfate;
e) calcium hydrosulfite +.

Salt production

Based on the studied properties of the main classes inorganic substances you can deduce 10 ways to obtain salts.
1. Interaction of metal with non-metal:
2Na + Cl2 = 2NaCl
In this way, only salts of anoxic acids can be obtained. This is not an ionic reaction.
2. Interaction of metal with acid:
Fe + H2SO4 = FeSO4 + H2
Fe + 2H + + SO 2 4 - = Fe 2+ + SO 2 4 - + H2
Fe + 2H + = Fe 2+ + H2
3. Interaction of metal with salt:
Cu + 2AgNO3 = Cu (NO3) 2 + 2Ag ↓
Cu + 2Ag + + 2NO 3 - = Cu 2+ 2NO 3 - + 2Ag ↓
Cu + 2Ag + = Cu 2+ + 2Ag
4. The interaction of the basic oxide with acid:
CuO + H2SO4 = CuSO4 + H2O
CuO + 2H + + SO 2 4 - = Cu 2+ + SO 2 4 - + H2O
СuО + 2Н + = Cu 2+ + H2O
5. Interaction of the basic oxide with acid anhydride:
3CaO + P2O5 = Ca3 (PO4) 2
The reaction is not ionic.
6. The interaction of acidic oxide with a base:
CO2 + Ca (OH) 2 = CaCO3 + H2O
CO2 + Ca 2+ + 2OH - = CaCO3 + H2O
7, Reaction of acids with base (neutralization):
HNO3 + KOH = KNO3 + H2O
H + + NO 3 - + K + + OH - = K + + NO 3 - + H2O
H + + OH - = H2O

8. Interaction of the base with salt:
3NaOH + FeCl3 = Fe (OH) 3 + 3NaCl
3Na + + 3ОН - + Fe 3+ + 3Cl - = Fe (OH) 3 ↓ + 3Na - + 3Cl -
Fe 3+ + 3ОН - = Fe (OH) 3 ↓
9. Interaction of acid with salt:
H2SO4 + Na2CO3 = Na2SO4 + H2O + CO2
2H + + SO 2 4 - + 2Na + + CO 2 3 - = 2Na + + SO 2 4 - + H2O + CO2
2H + + CO 2 3 - = H2O + CO2
10. Interaction of salt with salt:
Ba (NO3) 2 + FeSO4 = Fe (NO3) 2 + BaSO4
Ba 2+ + 2NO 3 - + Fe 2+ + SO 2 4 - = Fe 2+ + 2NO 3 - + BaSO4 ↓
Ba 2+ + SO 2 4 - = BaSO4 ↓

■ 124. Give all the ways you know how to obtain barium sulfate (write all equations in molecular and ionic forms).
125. Give all the possible general ways of obtaining zinc chloride.
126. Mixed 40 g of copper oxide and 200 ml of 2 N. sulfuric acid solution. How much copper sulfate is produced?

SALTS OF PHOSPHORUS The average salts of orthophosphoric acid are called orthophosphates or simply phosphates, and the acidic ones are called hydrophosphates. They are distinguished by three ...