To date, there are more than 100 thousand of various inorganic substances.In order to somehow classify them, they are divided into classes.In each class are combined substance similar in composition and properties.

all inorganic substances are divided into simple and complex.Among simple substances recovered metals (Na, Cu, Fe), nonmetals (Cl, S, P) and inert gases (He, Ne, Ar).K complex inorganic compounds include such broad classes already substances, such as oxides, acids, hydroxides and salts of amphoteric.

oxides



oxides - a combination of two elements, one of which - oxygen.They have the general formula E (m) O (n), where «n» indicates the number of oxygen atoms, and «m» - number of atoms of another element.

are salt-forming oxides and nesoleobrazuyuschimi (indifferent).Salt-forming oxides by reactin
g with acids or bases to form salts indifferent - do not form salts.The latter include a few oxides: CO, SiO, NO, N2O.Salt-forming oxides already divided core (Na2O, FeO, CaO), acidic (CO2, SO3, P2O5, CrO3, Mn2O7) and amphoteric (ZnO, Al2O3).

Grounds



base molecule composed of a metal atom and hydroxide group -OH.Their general formula - Me (OH) y, wherein «y» indicates the number of hydroxy groups corresponding to the valence of the metal.Solubility base is classified into water-insoluble (alkali) and insoluble, according to the number of hydroxide groups - on odnokislotnye (NaOH, LiOH, KOH), diacid (Ca (OH) 2, Fe (OH) 2) and trehkislotnye (Ni (OH)3, Bi (OH) 3).



Acids Acids composed of hydrogen atoms can be replaced by metal atoms, and acid residues.They have the general formula H (x) (Ac), where «Ac» denotes acidic residue (from the English. Acid - acid), and «x» indicates the number of hydrogen atoms corresponding to the valence of the acid moiety.

on the basic, iethe number of hydrogen atoms to divide monobasic acid (HCl, HNO3, HCN), dibasic (H2S, H2SO4, H2CO3), tribasic (H3PO4, H3BO3, H3AsO4) and tetrabasic (H4P2O7).Acids with two or more hydrogen atoms are called multivalent.

By the presence of oxygen atoms in the molecule divided by anoxic acid (HCl, HBr, HI, HCN, H2S) and oxygen - oxo acids (HNO3, H2SO4, H3PO4).Anoxic acids are the result of the dissolution in water of the respective gases (hydrogen chloride, hydrogen bromide, hydrogen sulfide, etc.), hydrates and oxoacids are acidic oxides - products of the compounds with water.For example, SO3 + H2O = H2SO4 (sulfuric acid), P2O5 + 3H2O 2H3PO4 = (phosphoric acid).

amphoteric hydroxides



amphoteric hydroxides are the properties of acids and bases.Their molecular formula could also be written in the form of a base or acid form: Zn (OH) 2≡H2ZnO2, Al (OH) 3≡H3AlO3.

salts



salts - are products of replacement of hydrogen atoms of metals in acid molecules or hydroxide groups in the base molecule acid residues.At full replacement forms the middle (normal) salt: K2SO4, Fe (NO3) 3.Partial replacement of hydrogen atoms in the molecules of polybasic acids gives acid salt (KHSO4), hydroxide groups in the molecules mnogokislotnyh bases - basic salts (FeOHCl).There are, moreover, integrated and double salts.