No theory can be considered absolutely true.
Karl Popper
There is nothing more practical than a good theory.
Academician A.P. Alexandrov
Chapter 3
SOME POINTS OF THE THEORY OF ELECTROLYTE SOLUTIONS AND MASS ACTION LAW IN ANALYTICAL CHEMISTRY
3.1. SOME POINTS OF THE THEORY OF ELECTROLYTE SOLUTIONS USED IN ANALYTICAL CHEMISTRY (ANALYTICS)
3.1.1. Strong and weak electrolytes
Conductors, in which electric current flow causes transfer of a substance in ionic form (ionic conductivity) and chemical transformations (electrochemical reactions), are called electrolytes [the term "ion" was first introduced by the English physicist Michael Faraday (1791-1867)]. These can be individual substances or solutions.
A simplified formulation is as follows: electrolytes are substances that are able to decompose into ions in solutions. However, this formulation is less general and does not cover solid electrolytes and molten electrolytes.
A solution is a homogeneous mixture of two or more substances able to change its properties continuously. Solutions can be liquid and solid. Liquid solutions are generally used in analytics.
According to the electrolytic dissociation theory (1883-1887) proposed by Swedish scientist Svante Augustus Arrhenius (1859-1927), awarded in 1902 the Nobel Prize for development of the theory, electrolytes in solutions decompose (dissociate) into ions due to interaction with molecules of solvent.
Electrolyte ionisation (dissociation into ions) in solution is quantitatively characterised by degree of dissociation (ionization) α, that is equal to the ratio of number of dissociated molecules ndiss to initial number of molecules ninitial:
α -ndiss/ninitial.
Degree of dissociation (ionization) α is expressed quantitatively as a decimal quantity or in percentage terms. If α = 1 (i.e., 100%), then all initial particles decompose in solution into ions (ndiss = ninitial); if α <1 (i.e., less than 100%), then not all initial particles, but only part of them decompose into