Question

How is molecular polarity related to solubility?

Answer 1

Hint The principle of ‘like dissolves like’ is applied here simply. We should know that polar solvent will dissolve polar substances and non-polar solvent tends to dissolve non-polar substances.

Complete step by step solution:
Let us study about the polarity of substances and its solubility;
Polarity refers to the attraction between the molecules of a substance. This phenomenon is responsible for the dipole moment among the molecules.
Polarity is directly related to solubility in all terms.
When a solute will dissolve into the solvent, the cohesive forces amongst the same molecules will break down to form new bonds. The phenomenon of solubility will take in the following steps;
Step I- The solvent particles will move apart to make a space for the upcoming solute particles to be dissolved. The cohesive forces among the solvent molecules will break down and the endothermic reaction will take place.
Step II- Same will take place with solute molecules. This reaction will also be endothermic which will break the cohesive forces amongst the solute molecules.
Step III- The final step will be exothermic in nature as the solvent molecules will be attached to the solute molecules. The new bonds will hold up the solute molecules and solvent molecules together.
Thus, the space created by the solvent particles for the solute particles is filled up by the forces of attraction among them, holding them together.

Note: Do note that the polar solvent will never dissolve the non-polar substance under normal conditions and vice versa is also true. The charges must compulsorily cancel each other to make a space for each other in the solution.