Question

If a salt is insoluble in cold water but soluble in hot water, then the salt is:
A. Lead chloride
B. Mercurous Chloride
C. Silver Chloride
D. Mercuric Chloride

Answer 1

Hint: Any solute is soluble in the solvent when the solute is solvated by the solvent molecules. Solvation is the process that breaks the solute and surrounds the solute ions with the solvent ions and thus form the solution.

Complete step by step answer:
Solvation is the process that involves the rearranging of the atoms of the solute and the solvent around each other. This leads to the formation of solvation complexes.
Solvation involves the breaking of solute bonds as well as the formation of bonds between the solute and the solvent molecules.
Various forces of the attraction come into play like the hydrogen bonding and van der Waal forces of attraction.
Most metal chlorides are soluble in cold water but lead chloride is an exception for this case
Lead chloride is insoluble in cold water and soluble in hot water.
Lead ion has a borderline acidic nature in the context of a hard-soft acid-base theory.
Hard-hard and soft-soft interactions are favorable while the mixed interactions are not that favorable.
Water is a hard solvent. Hot water weakens the lead ion-anion bonds. That may be the case why lead chloride may be soluble in hot water.
Solvation involves the creation of bonds and the breaking of the bonds at the same time

So, the correct answer is Option A.

Note: Solvation and solubility are two different concepts, Solvation is a kinetic process and is quantified based on the rate while solubility quantifies the dynamic equilibrium.Solubility is related to the dynamic equilibrium state achieved when the rate of dissolution and the rate of precipitation is the same. The concept of dissolve is generally followed in chemistry which states that a polar solvent will dissolve a polar solute while a nonpolar solvent will dissolve a nonpolar solute.