What is solubilityy product? Explain the common ion effect on solubility of ionic salts.

Explanation

Solubility product: It can be defined as the product of concentration of cation and anion of a salt present in a saturated aqueous solution.
It is denoted with `K_(sp)`.
Units of `K_(sp)=("Mole"//"Lt")^(n)`
where `n=` Total number of ions that can be given by salt per molecule on ionization.
Factors effecting `K_(sp):K_(sp)` can be effected by two factors only.
There are a. nature of substance b. temperature.
Significance: Solubility product is very important in preferential precipitation process in qualitative analysis.
The solubility of an electrolyte in water decreases by the addition of another electrolyte which has one ion common with the electrolyte.
For example the solubility of NaCl decreases on addition of HCl to solution of NaCl in water which is known as salting out of water.
Acetic acid is weak acid and it undergoes partial ionization as follows.
`CH_(3)COOHhArrCH_(3)COO^(-)+H^(+)`
In case o such electrolytes there exists an equilibrium in between ions and molecular form. In such a condition the addition of electrolyte with common ions shifts teh equilibrium in backward direction which causes the decrease in solubility.
Significance:
1. common ion effect is an important phenomenon in qualitative analysis.
the common ion effect principle is also used in controlling the `H^(+)` ion concentration in buffer solution.