Question

Any precipitate is formed when
(A) Solution becomes saturated
(B) The value of ion product is less that then the value of solubility product
(C) The value of ion product is equal that then the value of solubility product
(D) The value of ion product is greater than the value of solubility product.

Answer 1

Hint: The precipitates are the insoluble ionic salt that settles down to the base when an ionic compound or salt is added to a solvent. Also, a precipitation reaction takes place when at least two ions are present in the solution (anion and cation),and both form bonds with each other due to attracting forces resulting in the formation of insoluble ionic salt or can say precipitates.

Complete Step by Step Solution:
A solubility product is a product of the concentration of ions each raised to the power of their stoichiometry coefficient (number of mol used) of electrolyte salt in a saturated solution. It is the measure of maximum solubility of ions in a saturated solution and above its value, no ions will dissolve but precipitate.
\[{{K}_{sp}}\text{ }>\text{ }ionic\text{ }product\]

If the value of the ion product is less than then the value of the solubility product, means the equilibrium or saturate point is not attained yet and still salt can dissolve in the given solvent so, no precipitation takes place. Whereas when the value of ion product is equal to the value of solubility product then it is in a saturated state and salt further cannot dissolve in solution and precipitate started to form.
\[{{K}_{sp}}\text{ = }ionic\text{ }product\]

If the value of the ion product is greater than the value of the solubility product then the solution will be in the supersaturated state because above the value of the solubility product no salt can dissolve further but ions form bond with each other and will get settle down to the base which is known as precipitation. Thus, the part which gets settled down is insoluble and that is precipitates.
\[{{K}_{sp}}\text{ }ionic\text{ }product\]
Thus, the correct option is D.

Note: It is important to note that the value of solubility product does not depend on the concentration of products but depends on temperature and it is fixed for a particular reaction at a fixed temperature. Below its fixed value of ionic product, precipitation does not occur, if its fixed value attains in solution so, precipitation starts, and above its fixed value, the precipitation occurs at a good rate.