From Big Medical Encyclopedia

SALTS — a class of the chemical compounds which are formed as a result of acid-base reaction. The pages dissolved in biol. liquids of an organism, play the defining role in creation of internal environment of an organism (see) and in maintenance of osmotic pressure (see), i.e. in distribution of water between fabrics and cells at the physiological level. Chloride, phosphate and carbonic sodium salts (see), potassium (see), calcium (see) and magnesium (see) represent the index mineral compounds which are contained in a human body and participating in mineral metabolism (see) and a water salt metabolism (see). Nek-ry S.' concentration in blood and urine is diagnostic test at diseases cardiovascular, urinary and other systems. In usual conditions of S. are the crystal substances having ionic structure.

Many S. of a rastvorima in water (see) and other polar solvents. At dissolution of S. in them dissociate on the ions (see) having positive charge — cations, to-rye are formed usually by the metals or groups of atoms behaving as metals (e.g., an ion of ammonium) and on the ions having a negative charge — anions, to-rye are formed by acid residues (e.g.,

Na2S04 2Na + + S04 ~; NH4N03& + —

NH4 - f N03). Water soluble S., except HgCl2, Cdl2 and nek-ry others, belong to strong electrolytes (see) and in solutions dissociate on ions completely (see. Dissociation in chemistry ).

In S.'s nature form deposits of various minerals, napr, stone (cooking) NaCl salt (see. Sodium chloride), KC1 sylvinite, CaC03-MgC03 dolomite, etc. In the dissolved S.'s condition are in waters of the rivers, lakes, seas and oceans. Pages are a part of liquid and dense fabrics of vegetable and animal organisms. Contains in a human body apprx. 5,5% of salts.

Distinguish average (normal) S., to-rye it is possible to consider as products of full substitution in a molecule to - you hydrogen atoms on atoms of metal or in a molecule of the basis of hydroxyls on acid residues (Na2C03, MgCl2, etc.); acid S., to-rye it is possible to consider as products of incomplete substitution in a molecule to - you hydrogen atoms on atoms of metal (NaHC03, KH2P04, K2HP04, etc.), and the main S. — products of incomplete substitution in molecules of the bases of hydroxyls with acid residues [Bi(0H)2N03, Zn(OH)Cl, etc.]. At dissociation in solutions acid S. except metal cations form also hydrogen ions

of H+: NaIiC03 Na + + N + + C03";

basic salts except anions of acid residues — ions of a hydroxyl IT": Mg(OH)Cl *±Mg2 + - f IT" + + C1 ~. There are so-called double S., cations of different metals, e.g. KA1(S04)2 are a part to-rykh; anions different to - t, e.g. CaCl(OCl) are a part of the mixed S. Complex salts (see. Complex connections), in addition to simple ions, dissociate on complex ions — complex anions, e.g. KJFe(CN)6] <± 4K+ - f [Fe(CN)6]4-, or complex cations, e.g.

[Cu(NH3)4]S04? ± [Cu(NH3)4]2+ + SO2'.

Solutions and fusions C. carry electric current and at the same time are exposed to electrolysis (see). All water soluble S., except for KC1 formed strong to-tami and the strong bases, e.g., Na2S04, are exposed to hydrolysis (see). Villages easily enter substitution reactions and double replacement, e.g. CuS04 + >Fe-FeS04 + Gu, AgN03 + + KC1 -> AgCl + KN03. From solutions C. weak to - t stronger to - you force out weak to - you; >CH3COONa-+-+HCl-NaCl + CH3COOH, and from solutions C. of mild bases stronger bases force out mild bases: CuS04 + 2NaOH —> Cu(OH)2 + + Na2S04.

Interactions belong to the most important ways of receiving S.: 1) the bases with to-tami (neutralization test), e.g. A game + HN03 —> KN03 + H20; 2) acids with the main oxides, e.g. 2HC1 - j-SAO —> Sas12 + H20; 3) the bases with acid oxides, e.g. 2KOH + + C02 —» K2C03 + H20; 4) acids with salts, e.g. Vas12-f of H2S04 —> — >BaS04 + 2HC1; 5) alkalis with salts; e.g. 2NaOH + CuS04 —> —> Na2S04 + >Cu(OH)2; 6) two various salts, e.g. AgN03 + - f-NaBr-^AgBr ~ f NaN03; 7) the main oxides with acid oxides, e.g. SAO + C02 —» Sas03; 8) metals with nonmetals, e.g. Sa + C12 —» —> Sas12; 9) active metals with acids, e.g. Zn + 2HC1 —>-^пС124-Н2; 10) amphoteric metals with alkalis, e.g. Zn - j-2NaOH —> —» Na2Zn02 + H2; 11) metals with solutions of salts, e.g. Fe + CuSO* —>-^FeS04 + the SI.

Names C. are under construction according to the international nomenclature and are made from the name of metal or the group of atoms playing a role of metal, and armor. names of an acid residue, a cut it is formed from armor. names corresponding to - you. At the same time the name of salt oxygen-free to - you terminates on - ides, oxygen-containing to - you on - at (in case of maximum valency of an acid-forming element) and on - it (in case of its lower valency). So, e.g., salt salt to - you are chloride, salt a chamois to - you are sulfate, salt sulphurous to - you are sulfite. If salt is formed by metal with a variable valency, then the valency of metal is specified in brackets, e.g. FeS04 — ferrous sulfate (II), Fe2(S04)3 — ferrous sulfate (III). The name of acid salt has a prefix gidro-, pointing to availability of not replaced hydrogen atoms; if or it is more such atoms two, then their number is designated Greek numerals (di - three - etc.), e.g. Na2HP04 call hydrosodium phosphate, and NaH2P04 — dihydrosodium phosphate. Basic salt has a prefix gidrokso-, Bi(0H)(N03)2 indicating existence of not replaced hydroxylic groups, e.g. is called gidroksonitraty bismuth, and by Bi(0H)2N03 — digidroksonitraty bismuth. In the provided table names of nek-ry major Pages are given.

The table


See also Crystalline hydrates .

Bibliography: Glinka N. L. General chemistry, M., 1980; To Sleybo U. and Person T. The general chemistry, the lane with English, M., 1979, bibliogr.

V. P. Mishin.