modern chemistry is a wide variety of sectors, and each of them, in addition to the theoretical framework, is of great practical importance, practical.Whatever you tap all around - products of chemical production.The main sections - it is inorganic and organic chemistry.Consider what the main classes of inorganic substances belong to and what properties they possess.
main categories of inorganic compounds
To those accepted to the following:
Each class is represented by a wide variety of compounds of inorganic nature, and has a value of almost any structure of economic and industrial activities of man.All the major features that are typical of these compounds being in nature and getting taught in school chemistry course mandatory in grades 8-11.
There is a common table oxides, salts, bases, acids, which are examples of each of the substances and their physical state, being in nature.And also shows the relationships that describe chemical properties.However, w
group of compounds - oxides
oxides - a class of inorganic compounds consisting of two components (binary), one of which is always O (oxygen) to the lower oxidation state of -2, which stands in second place in the empirical formula of the substance.Example: N2O5, CaO and so on.
oxides are classified as follows.
I. Nesoleobrazuyuschie - not capable of forming salts.
II.Salt-forming - can form salts (with the bases, amphoteric compounds with each other acids).
- Acid - in contact with the water to form acid.Formed non-metals or metals often high CO (oxidation state).
- Key - in contact with the water to form the base.Formed metal elements.
- amphoteric - show acid-base dual nature, which is determined by the reaction conditions.Formed by transition metals.
- Mixed - often refer to salts and elements are formed in several oxidation states.
higher oxides - this oxide in which the generating element is in the maximum oxidation state.Example: Te + 6.For tellurium maximum degree of oxidation of +6 means TeO3 - higher oxides for this item.In the periodic table of elements under each group signed a general empirical formula reflecting higher oxides for all elements that are in this group, but only the main group.For example, a first group of elements (alkali metals) should formula R2O form, which means that all the elements of the main subgroup of this group will be higher for this kind of an oxide.Example: Rb2O, Cs2O and so on.
When dissolved in water, the higher oxide, we obtain the corresponding hydroxide (lye, acid or amphoteric hydroxide).
oxides can exist in all states of aggregation under normal conditions.Most of them is in a solid crystalline or powder form (CaO, SiO2), some of the CO (acid oxides) found in the form of liquids (Mn2O7), and gases (NO, NO2).This is due to the structure of the crystal lattice.Hence the difference in the boiling and melting temperatures that vary among different representatives from -2720S to + 70-800S (sometimes higher).The solubility in water varies.
- Soluble - basic metal oxides, known as alkali, alkaline earth and all acid except silicon oxide (IV).
- Insoluble - amphoteric oxides, all other basic and SiO2.
What oxides react?
oxides, salts, bases, acids exhibit similar properties.General properties of almost all oxides (except nesoleobrazuyuschih) - this ability as a result of specific interactions to form various salts.However, for each group of oxides, characterized by their specific chemical characteristics reflecting properties.
|Basic oxides - GS||Acidic oxides - KO||Dual (amphoteric) oxides - JSC||oxides, which do not form salts|
1.Reactions with water: formation of alkalis (oxides of alkali and alkaline earth metals)
Fr2O + water = 2FrOH
2. Reactions with acids: formation of salts and water
acid + Me + nO = H2O + Salt
3. Reaction with CO, the formation of salts and water
lithium oxide + nitrogen oxide (V) = 2LiNO3
4. The reactions as a result of which the elements change with
Me + nO + C = Me0 + CO
1. Reagent water: Educationacids (SiO2 exception)
CO + water = acid
2. Reactions with bases:
CO2 + 2CsOH = Cs2CO3 + H2O
3. Reactions with basic oxides: salt formation
P2O5 + 3MnO = Mn3 (PO3)2
4. Reactions OVR:
CO2 + 2Ca = C + 2CaO,
Expressed dual properties interact on the principle of acid-base method (with acids, alkalis, basic oxides, acid oxides).Since water does not come into interaction.
1. acid: formation of salts and water
AO + Acid = G + N2O
2. With bases (alkalis): education hydroxycomplexes
Al2O3 + LiOH + water = Li [Al (OH) 4]
3. Reactions with acid oxides: obtaining salts
FeO + SO2 = FeSO3
4. Reactions GS: salt formation, fusion
MnO + Rb2O = double salt Rb2MnO2
5. fusion reactions with alkalis and carbonates of alkali metals:salt formation
Al2O3 + 2LiOH = 2LiAlO2 + H2O
|not constitute either acid or alkaline.Show narrowly specific properties.|
Each top oxide formed as the metal and nonmetal, dissolved in water, gives a strong acid or alkali.
Organic acids and inorganic
In classic speaker (based on the positions of ED - electrolytic dissociation - Svante Arrhenius acid) - this compound in an aqueous medium to dissociate the H + cations and anions An- acid residues.Today, however, carefully studied acid and anhydrous conditions, so there are many different theories to hydroxides.
Empirical formula oxides, acids, salts are added only from the characters, items, and an index indicating their number in the substance.For example, inorganic acids expressed by the formula H + acid residue n-.Organic substances are more theoretical mapping.In addition to the empirical, they can write the names and acronyms structural formula that will reflect not only the composition and quantity of the molecules, but also the order of the atoms, their connection with each other and the main functional group for the carboxylic acid COOH.
In all inorganics acids are divided into two groups:
- anoxic - HBr, HCN, HCL and others;
- oxygen (oxo acids) - HClO3 all, where there is oxygen.
also inorganic acids are classified according to the stability (stable or stable - except coal and sulfur, volatile or unstable - coal and sulfur).By the force of strong acids may be: sulfuric, hydrochloric, nitric, perchloric and others, as well as weak: hydrogen sulfide, hypochlorous and others.
Not such a variety of offers organic chemistry.The acids which are organic in nature, include carboxylic acids.Their common feature - the presence of the functional group COOH.For example, HCOOH (formic acid) CH3COOH (acetic) S17N35SOON (stearic acid) and others.
There are a number of acids, which carefully emphasizes the consideration of the subject in the school chemistry course.
- Acetic or ethane.
- butane or oil.
data 10 acids are the basic chemical substances corresponding class in the school course, and the whole industry and syntheses.
properties of inorganic acids
The main physical properties must be attributed first and foremost a different state of aggregation.After all, there are a number of acids, having the form of crystals or powders (boric, phosphoric) at normal conditions.The vast majority of the known inorganic acids is a different liquid.Boiling point and melting also vary.
acid can cause severe burns, as they have the power of destroying organic tissue and skin.For the detection of acids used indicators:
- methyl orange (normal medium - orange in acids - red),
- litmus (neutral - violet in acid - red) or some other.
The most important chemical properties include the ability to interact with both simple and complex substances.
|What interact||example reaction|
1. With simple materials-metals.Prerequisite: the metal must be in EHRNM to hydrogen as metals, standing after hydrogen, are not able to oust him from the acid.The reaction is always formed in the form of hydrogen gas and salt.
HCL + AL = aluminum chloride + H2
2. With the bases.The result of the reaction are salt and water.Similar reactions of strong acids, alkalis are called neutralization.
Any acid (strong) + = base soluble salt and water
|3. With amphoteric hydroxides.Outcome: salt and water.|| |
2HNO2 + beryllium hydroxide = Be (NO2) 2 (average salt) + 2H2O
|4. With basic oxides.Bottom line: water, salt.|| |
2HCL + FeO = chloride, iron (II) + H2O
|5. With amphoteric oxides.The final effect: salt and water.|| |
2HI + ZnO = ZnI2 + H2O
6. With the salts formed by weaker acids.The final effect: salt and a weak acid.
2HBr + MgCO3 = magnesium bromide + H2O + CO2
The interaction with metals, not all react the same acid.Chemicals (grade 9) in school involves a very shallow study of such reactions, however, and at such a level considered specific properties of concentrated nitric acid and sulfuric acid by reaction with metals.
hydroxides: alkali, amphoteric and insoluble base
oxides, salts, bases, acids - all of these classes of compounds have the general chemical nature, explains the structure of the crystal lattice, and the mutual influence of atoms in the molecules.However, if the oxides could be given a very specific definition, for the acids and bases do it harder.
Just as acids, bases on the theory of ED are substances capable of disintegrating in an aqueous solution of metal cations and anions Men + OH- gidroksogrupp.
categorized base as follows:
- soluble or alkali (strong bases, color-changing indicators).Metal-formed I, II groups.Example: KOH, NaOH, LiOH (ie elements are taken into account only the main group);
- poorly soluble or insoluble (medium strength, do not change the color of the indicator).Example: magnesium hydroxide, iron (II), (III), and others.Molecular
- (weak base in an aqueous medium reversibly dissociate into ions, molecules).Example: N2H4, amines, ammonia.
- amphoteric hydroxides (exhibit dual acid-base properties).Example: aluminum hydroxide, beryllium, zinc and so on.
each submission group studied in the school course of chemistry in the "Grounds".Chemistry 8-9 class involves a detailed study of alkali and soluble compounds.
All bases and alkali soluble compounds found in nature in the solid crystalline state.Wherein the melting temperature of their usually low, and poorly soluble hydroxides decompose when heated.Color different reasons.If alkali white crystals of the molecular bases of poorly soluble and can be very different coloring.The solubility of most of this class of compounds can be found in the table, which presents the formula oxides, acids, salts, shows their solubility.
Alkalis can change the color of the indicator as follows: phenolphthalein - crimson, methyl orange - yellow.This is ensured by the presence of free gidroksogrupp solution.That is why poorly soluble base such reactions do not give.
chemical properties of each group are different reasons.
|alkali||poorly soluble bases||amphoteric hydroxides|
I. interaction with CO (up -hydrochloric and water):
2LiOH +SO3 = Li2SO4 + water
II.With an acid (salt and water):
conventional neutralization (see acid)
III.Interact with AO to form hydroxo salt and water:
2NaOH + Me + n O n = Na2Me + H2O + O2, or Na2 [Me + n (OH) 4]
IV.Interact with amphoteric hydroxides to form salts gidroksokompleksnyh:
The same as with the stock, but without water
V. interacts with soluble salts to form insoluble salts and hydroxides:
3CsOH + iron chloride (III) = Fe (OH) 3 + 3CsCl
VI.Interact with zinc and aluminum in an aqueous solution to form the salt and hydrogen:
2RbOH + 2Al + water = complexed with hydroxide ion 2Rb [Al (OH) 4] + 3H2
I. Upon heating degradability:
insolublehydroxide oxide + water =
II.Reactions with acids (total: salt and water):
Fe (OH) 2 + 2HBr = FeBr2 + water
III.Interact with KO:
Me + n (OH) n + CO = G + H2O
I. react with acids to form salts and water:
copper hydroxide (II) + 2HBr = CuBr2 + water
II.Reacts with alkalis: result - salt and water (condition: fusion)
Zn (OH) 2 + 2CsOH = G + 2H2O
III.Reacts with strong hydroxides: result - salt, if the reaction proceeds in an aqueous solution:
Cr (OH) 3 + 3RbOH = Rb3 [Cr (OH) 6]
This is most of the chemical properties of that display base.Chemistry reason is quite simple and is subject to the general laws of inorganic compounds.
class of inorganic salts.Classification, physical properties
Drawing on the ED can be named inorganic salts of the compound in aqueous solution is dissociated into metal cations Me n + and anions of acidic residues Ann-.So it is possible to present salt.Determination chemistry provides not one, but it is the most current.
Thus in their chemical nature all salts are divided into:
- acidic (having a part of hydrogen cation).Example: NaHSO4.
- Key (available as part of gidroksogrupp).Example: MgOHNO3, FeOHCL2.
- Average (consists only of the metal cation and the acid residue).Example: NaCL, CaSO4.
- double (include two different metal cation).Example: NaAl (SO4) 3.
- Complex (hydroxocomplexes, aqua complexes and others).Example K2 [Fe (CN) 4].
Formula salts reflect their chemical nature, as well as talk about the qualitative and quantitative composition of the molecule.
oxides, salts, bases, acids have different ability to solubility, which can be viewed in the corresponding table.
If we talk about the state of aggregation of salts, it is necessary to observe their monotony.They exist only in the solid, crystalline or powder form.The color range is quite diverse.The solutions of complex salts usually have bright saturated colors.
chemical interaction for middle-class salt
have similar chemical properties of the base, acid, salt.Oxides, as we have already discussed, differ from them in this factor.Total
can distinguish four basic types of interactions for medium salts.
I. Interaction with acids (only strong in terms of the ED) to form another salt of a weak acid:
KCNS + HCL = KCL + HCNS