Question

Which is insoluble in water?

Answer 1

Hint: Solubility is defined as a property of a solid, liquid or gaseous chemical substance called solute to dissolve in a solvent and form a solution. Based on the concentration of solute dissolves in a solvent, solutes are classified into three categories, namely highly soluble, sparingly soluble and insoluble. There are three types of solution even, they are unsaturated solution, saturated solution and supersaturated solution.

Complete answer:
Let's describe the types of solute;
Highly soluble: A substance which can be dissolved easily in solvent generally water, and gives a clear solution is known to be highly soluble. Alkalis are very easily dissolved in water.
Example- \[NaOH\],\[KOH\].
Sparingly soluble: A substance which has low solubility or if \[1g\] of substance requires \[100\] to \[1000ml\] of solvent to dissolve is known as sparingly soluble.
Example- All sulphides are slightly soluble in water. \[MgS\],\[CaS\] etc
Insoluble: An insoluble substance is a substance that will not dissolve in a solvent even after mixing.
Example- sand, fats, wood and metals.
Those molecules which have minimum ionic character are least soluble in water. In other words higher the ionic character higher will be the solubility and higher the covalent character (least ionic character) least will be the solubility. The covalent character will be high when the size of the anion is bigger and the bond strength between the two ions is greater than the strength of it and the water. Hence the covalent molecules will be insoluble in polar solvents generally water.
Example- \[AgI\],\[Ca{F_2}\],\[CaC{O_3}\] etc.

Note:
-An unsaturated solution is a solution in which more solute can be dissolved at a given temperature.
-A saturated solution is a solution containing the maximum amount of solute that will dissolve at a given temperature.
-A supersaturated solution is a solution that contains more solute than would dissolve in a saturated solution at a given temperature.