Dissociation of salt

What is the dissociation of salts

������Acids, bases, salts undergo dissociation. Most salts are strong. This means that their solutions or melts conduct electricity well, due to the formation of a large number of charged particles - ions.

What is the mechanism of salt dissociation in solutions or melts?


Imagine what will happen to table salt well known to all people if its crystals are melted or thrown into water. This substance has an ionic lattice structure. When melting, thermal energy will lead to the fact that the oscillations of ions in the lattice sites will increase many times, as a result of which the bonds between neighboring ions will begin to break. Free ions will appear. And this process with continued heating will continue until the complete destruction of the crystal lattice. A similar mechanism of destruction will occur when the salt crystals dissolve in water, but instead of thermal energy, water molecules act here, as if "stretching" crystals into individual particles.
For the first time, the theory of electrolytic dissociation was put forward by two chemists - Arrhenius and Ostwald at the end of the 19th century. It is through dissociation that the properties of salts are described, as well as bases and acids. Sour and basic salts undergo dissociation stepwise, for example, KHSO4 = K ^ + + HSO4 ^ -

What are the features of salt dissociation?


During the dissociation of salts, positively charged metal cations (or ammonium cation) are formed, as well as negatively charged cations of acid residues. The process of dissociation is depending on which salt undergoes dissolution or melting (medium, acidic or basic).
If the salt is medium (that is, formed by an acid, in the molecules of which all hydrogen cations are replaced by metal, or ammonium cations), the dissociation occurs according to such schemes, in one stage:
KNO3 = K ^ ++ NO3 ^ -
Na2SO4 = 2Na ^ ++ SO4 ^ 2-
Sour and basic salts dissociate in several stages. The acid salt (that is, formed by an acid, the hydrogen cations of which are not completely replaced) first loses the metal ion, and then the hydrogen cation is split off. For example:
NaHSO4 = Na ^ ++ HSO4 ^ -
HSO4 ^ - = H ^ ++ SO4 ^ 2-
For the basic salts (i.e., those formed by alkalis, in which the hydroxyl groups are not completely replaced), acidic residues are first split off, and then OH ^ - ions.

Video: How Water Dissolves Salt


Images: What is the dissociation of salts What is the dissociation of salts
Images: What is the dissociation of salts What is the dissociation of salts