Question

What is the ${K_{sp}}$ expression for the salt $Pb{I_2}$ ?

Answer 1

Hint : The solubility product constant is defined as the equilibrium constant for the dissolution of a solid substance into an aqueous solution. It is represented with the symbol ${K_{sp}}$ . The value of the solubility product is dependent on temperature. The ${K_{sp}}$ increases when the temperature is increased. This is because of increased solubility.

Complete Step By Step Answer:
The property of a substance called solute to get dissolved in a substance called solvent to form a solution is called solubility. The solubility of different ionic compounds is different because some compounds are highly soluble, some are highly insoluble while some even absorb moisture from the atmosphere. The equilibrium constant ${K_{sp}}$ for the dissolution of a solid into aqueous solution is the solubility product constant.
Therefore, the ${K_{sp}}$ expression for the salt $Pb{I_2}$ is given by: ${K_{sp}} = [P{b^{2 + }}]{[{I^ - }]^2}$ .

Additional Information:
The solubility depends on many parameters out of which lattice enthalpy of the salt and solvation enthalpy of ions in the solution are most important. If a salt is dissolved in a solvent, the strong forces of attraction of the solute should be overcome by the interaction between the ions and the solvent. As energy is released during the process, the solvation enthalpy is negative always. The amount of energy released during solvation is determined by the nature of the solvent. The solubility is different for different salts.

Note :
Some factors like the common-ion effect, the diverse-ion effect and presence of ion pairs affect the value of solubility product constant. If a common ion is present, the value of the solubility product constant is lowered. If the ions present in the solute are not common, then the value of the solubility product constant will be higher.