Question

Explain any four factors which affect the solubility of ionic compounds.

Answer 1

As we know that solubility of a substance is the ability for a given substance that is solute to dissolve in a solvent. Solubility depends on the chemical and physical properties of the substance and on other factors like temperature, pressure etc.

Complete step by step answer:
- As we know that the ionic compounds are affected by the common ion effect, temperature, solute-solvent interaction and molecular size.
- Let’s discuss in brief about all these factors:
- Common ion effect: It is found that ionic compounds are soluble in solvents that have a common ion. For example, calcium sulphate that is slightly soluble in water. We can see here that if the water already contains sulphate or calcium ions, then the position of equilibrium will move to the left and hence the solubility decreases.
- Molecular size: It is found that larger the size of the molecules of the solute, the larger will be their molecular weight. Basically, it is difficult for the solvent molecules to surround the bigger molecules.
- Temperature: As there will be an increase in the temperature, the solubility of the ionic compounds will also increase.
- Solute-solvent interaction: It is found that solubility of the ionic compounds increases, if there will be strong solute-solvent interaction. Basically, ionic compounds are soluble mostly in polar solvents like water, this is because ions of the solid are attracted to the polar solvent molecules.
- Hence, we can conclude that the four factors which affect the solubility of ionic compounds are common ion effect, temperature, solute-solvent interaction and molecular size.

Note: There is a general rule found that larger particles are basically less soluble. If temperature and the pressure are the same, then among the two solutes having the same polarity, the solute with smaller particles is more soluble.