Advice 1: How to define strong and weak electrolytes

Electrolytes are substances, alloys of substances or fluids that have the ability to electrolytically conduct a galvanic current. To determine which electrolytes a substance, applying the theory of electrolytic dissociation.
How to define strong and weak electrolytes
The essence of this theory is that the melting (dissolving in water) almost all electrolytes are decomposed into ions which are positively or negatively charged (which is called electrolytic dissociation). Under the influence of the electric current is negative (anions "-") move to the anode ( + ) and positively charged (cation,+) to move to the cathode (-). Electrolytic dissociation is a reversible process (the reverse process is called "polaryzacja").
Degree (a) electrolytic dissociation is dependent on the nature of the electrolyte, solvent, and concentration. It is the ratio of the number of molecules (n) that fell apart into ions to the total number introduced into the solution of molecules (N). Get: a = n / n
Therefore, strong electrolytes - substances, disintegrating completely into ions when dissolved in water. For strong electrolytes, as a rule, are substances with ionic bonds or silnoroslye: this salt is very soluble, strong acid (HCl, HI, HBr, HClO4, HNO3, H2SO4) and strong bases (KOH, NaOH, RbOH, Ba(OH)2, CsOH, Sr(OH)2, LiOH, Ca(OH)2). In a strong electrolyte is a substance dissolved in it, is mostly in the form of ions (anions and cations); molecules that medicationabana - almost none.
Weak electrolytes - substances which dissociate into ions only partly. Weak electrolytes together with ions in a solution containing molecules medicationabana. Weak electrolytes do not give to the solution high concentrations of ions.

To weak include:
- organic acids (almost all) (C2H5COOH, CH3COOH, etc.);
some of the inorganic acids (H2S, H2CO3, etc.);
- almost all of the salt, slightly soluble in water, ammonium hydroxide, as well as all grounds (Ca3(PO4)2; Cu(OH)2; Al(OH)3; NH4OH);
- water.

They practically do not conduct electricity or conduct, but bad.
Although pure water conducts electricity very poorly, she still has measurable electrical conductivity and explain the fact that water is slightly dissociated into hydroxide ions and hydrogen ions.
Useful advice
Most electrolytes – substances aggressive, so when handling them be very careful and observe safety rules.

Advice 2 : How to identify strong electrolytes

Electrolyte – a substance that in the solid state is an insulator, i.e. does not conduct electric current, however, in dissolved or molten form becomes a conductor. Why is such an abrupt change in properties? The fact that the molecules of an electrolyte in solutions or melts dissociate into positively charged and negatively charged ions, whereby these substances in such aggregate as is capable of conducting an electric current. Electrolytic properties of most salts, acids, bases.
How to identify strong electrolytes
All electrolytes are equal in strength, that is, are good conductors of electricity? No, because many substances in solutions or melts dissociate only to a small extent. Therefore, electrolytes are classified into strong, medium and weak forces.
What substances are strong electrolytes? Such substances in solutions or melts which are subjected to dissociation almost 100% of molecules regardless of the concentration of the solution. In the list of strong electrolytes includes the absolute most soluble alkalis, salts and some acids such as hydrochloric, bromide, iodide, nitrogen, etc.
What a difference electrolytes the average force? The fact that they dissociate to a much lesser extent (in the ions decay from 3% to 30% of the molecules). Classical representatives of such electrolyte – sulfuric and phosphoric acid.
And the behavior in solutions or melts of weak electrolytes? First, they dissociate to a very small extent (not more than 3% of the total number of molecules), and secondly, their dissociation is the worse and slower, the higher the concentration of the solution. Such electrolytes include, for example, ammonia (ammonium hydroxide), most organic and inorganic acids (including hydrofluoric – HF) and of course we are all familiar is water. Since only a very small fraction of its molecules splits into hydrogen ions and hydroxyl ions.
Remember that the degree of dissociation and, accordingly, the strength of the electrolyte are dependent on many factors: the nature of the electrolyte, solvent, temperature. Therefore, the division is somewhat arbitrary. It's one and the same substance may, under different circumstances, to be both a strong electrolyte and weak. To assess the strength of the electrolyte was introduced with a special value is the dissociation constant determined on the basis of the law of mass action. But it is applicable only to weak electrolytes strong electrolytes the law of mass action do not obey.
Is the advice useful?