Inorganic substances are simple and complex substances, except organic compounds of carbon. Objects of inanimate nature consist of them: soil, air, Sun. Some are a part of living cells. Several hundreds of inorganic substances are known. According to the properties, they are divided into a number of classes.
That carry to inorganic substances
First, simple substances are inorganic: they consist of atoms of one chemical element. For example, it is oxygen, gold, silicon and sulfur. However, all table of Mendeleyev belongs here.
Secondly, many complex substances (or connections) belong to number of inorganic which part atoms of several elements are. An exception are carbon organic compounds which form a separate extensive class of substances. They have special structure which cornerstone the so-called carbon skeleton is. Some compounds of carbon, however, belong to inorganic.
Features of inorganic substances:
- Molecules are usually connected by ionic communication. That is, atoms of elements with low electronegativity "give" electrons to atoms of other simple substance. As a result raznozaryazhenny particles - ions ("with plus" - a cation and "with minus" - anion) which are attracted among themselves are formed.
- Molecular weight small if to compare to the majority of organic compounds.
- Chemical reactions between inorganic substances proceed quickly, sometimes instantly.
- The majority of inorganic substances are to a degree dissolved in water. At the same time they break up (dissociate) to ions thanks to what carry electric current.
- Most often, it is solid substances (though gases and liquids meet). At the same time they have high temperature of melting, and when melting do not collapse.
- As a rule, are not oxidized on air and it is not combustible. So, after fuel combustion (for example, firewood or coal) mineral impurity remain in the form of ashes.
Some inorganic substances are a part of cages of living organisms. It is, first of all, water. Also important role is played by mineral salts.
Simple and complex inorganic substances are subdivided into several classes, each of which has various properties.
Simple inorganic substances
- Metals: lithium (Li), sodium (Na), copper (Cu) and others. From the physical point of view usually it is firm (except liquid mercury) substances with characteristic gloss, high warm and conductivity. As a rule, in chemical reactions they are reducers, that is give the electrons.
- These are, for example, gases fluorine (F2), chlorine (Cl2) and oxygen (O2). Solid nonmetallic simple substances - sulfur (S) phosphorus (P) and others. In chemical reactions usually act as oxidizers, that is attract electrons of reducers.
- Amphoteric simple substances. Have the dual nature: can show both metal, and nonmetallic properties. Carry to such substances, in particular, zinc (Zn), aluminum (Al) and manganese (Mn).
- Noble, or inert, gases. It is helium (He), neon (Ne), argon (Ar) and others. Their molecules consists of one atom. Are chemically inactive, capable to form connections only in special conditions. It is connected with the fact that outer electron shells of atoms of inert gases are filled: they both do not give the, and do not take away electrons of other elements.
Inorganic compounds: oxides
The class of complex organic compounds, most widespread in the nature, are oxides. One of the major substances – water, or oxide of hydrogen (H2O) belongs to their number.
Oxides arise in interaction of various chemical elements with oxygen. At the same time atom of oxygen attaches to itself two "others" electrons.
As oxygen - one of the strongest oxidizers, almost all binary (the containing two elements) connections with it are oxides. Oxygen is oxidized only fluorine. The received substance - OF2 - belongs to fluorides.
Allocate several groups of oxides:
- the main (with an accent on the second syllable) oxides are compounds of oxygen with metals. React with acids, at the same time salt and water are formed. Carry to the main, in particular, oxide of sodium (Na2O), oxide of CuO copper (II);
- acid oxides are connections with oxygen of nonmetals or transitional metals in oxidation level from +5 to +8. Interact with the bases, at the same time there are a salt and water. Example: NO2 nitrogen oxide (IV);
- amphoteric oxides. React both with acids, and with the bases. It is, in particular, the oxide of zinc (ZnO) which is a part of dermatological ointments and powders;
- not salt-forming oxides which do not react with acids and with the bases. For example, that are CO2 and CO carbon oxides, it is good all known as carbonic and charcoal gases.
Hydroxides
Hydroxides contain so-called hydroxyl group in the structure (-OH). It includes on atom of oxygen and hydrogen. Hydroxides are divided into several groups:
- the bases are hydroxides of metals with low oxidation level. The soluble bases in water are called alkalis. Examples: caustic soda, or sodium hydroxide (NaOH); extinguished lime, it is hydroxide of calcium (Ca(OH)2).
- acids are hydroxides of nonmetals and metals with high oxidation level. Most of them are liquids, is more rare – solid substances. Almost all are soluble in water. Usually acids very caustic, poisonous. In production, medicine and other spheres actively use sulfuric acid (H2SO4), nitric (HNO3) and some other;
- amphoteric hydroxides. Show the main, acid properties. For example, hydroxide of zinc (Zn(OH)2) belongs here.
Salts
Salts consist of the cations of metal connected with negatively charged molecules of the acid rest. Also there are ammonium salts - NH4+ cation.
Salts arise in interaction of acids with metals, oxides, the bases or other salts. Hydrogen as a part of acid at the same time is partially or completely forced out by metal atoms therefore during reaction hydrogen or water is also emitted.
Short description of some groups of salts:
- average salts - in them hydrogen is completely replaced on metal atoms. For example, it is the ortho-phosphate of potassium (K3PO4) applied in production food E340 additives;
- sour salts as a part of which there is a hydrogen. The hydrocarbonate of sodium (NaHCO3) - baking soda is widely known;
- the main salts - contain hydroksogruppa.
Binary connections
Separately distinguish binary connections from inorganic substances. Atoms of two substances are their part. It can be:
- oxygen-free acids. For example, hydrochloric acid (HCl) which is a part of gastric juice of the person;
- oxygen-free salts which arise in interaction of oxygen-free acids with metals or two simple substances among themselves. Usual table salt, or chloride of sodium (NaCl) belongs to such salts;
- other binary connections. It is, in particular, the carbon sulfur (CS2) which is widely applied in chemical industry and other industries.
Inorganic compounds of carbon
As it is already noted, some compounds of carbon belong to inorganic substances. It:
- coal (H2CO3) and hydrocianic acids (HCN);
- carbonates and hydrocarbonates - salts of coal acid. The simplest sample - the same baking soda;
- carbon oxides - carbon and carbon dioxide;
- carbides - compound of carbon with metals and some nonmetals. Are solid substances. Because of the refractoriness are widely applied in metallurgy to receiving high-quality alloys and also in other industries;
- cyanides are salts of hydrocianic acid. Notorious potassium cyanide, the strongest poison is among.
Carbon also contains in the nature in pure form, and in several unlike forms. Powdery soot, layered graphite and the most solid mineral on Earth, diamond, - all of them have chemical formula C. Naturally, they are inorganic substances too.