Question

How does ion size relate to solubility?

Answer 1

Solubility is the amount of substance soluble to make a saturated solution at a specified temperature. The maximum amount of solute that can dissolve in a known quantity of solvent at a certain temperature. Solubility helps the molecules to dissolve. Some factors that affect solubility of a substance are temperature—By changing temperature we can increase solubility. Next is intermolecular forces or bonds, pressure—when partial pressure increases, solubility increases and the size of the ions.

Complete step by step answer:
As we know that smaller ions are less soluble than the larger ones. The reason behind it is that:
Solubility is all about competition because the ions in the water attract each other and the water molecule also attracts the ions.
If a water molecule has a greater force of attraction towards the ions than the force of attraction between the ions itself, then that compound will be more soluble in water.
But if the force of attraction between water molecules and ions is less than the force of attraction between the ions then that compound will be less soluble.
In small ions, the ions are close apart to each other because they have stronger attractive forces. It becomes difficult for water molecules to pull them apart so they are less soluble.
But in larger ions they are far with each with less attractive forces so that water molecules can easily break them apart and attract towards it so they are more soluble.
So we can conclude in lat. That: solubility increases as the size of ions increases.

Note: Due to solubility of ions electrical conductivity decreases
To calculate solubility of substances temperature is kept constant throughout the system.
Solubility formula expressed as $\text{s}=\sqrt{\text{Ksp}}$
Ksp $=$ solubility product constant.
Solubility is calculated as the molarity of the material under excessive undissolved material in a solution.