Ionic solutions are typically more conductive than covalent solutions when both are completely saturated under normal conditions. This is because ionic solutions contain ions that are responsible for carrying electric charge and facilitating the flow of current. In contrast, covalent solutions generally do not dissociate into charged species to the same extent, resulting in lower conductivity.
In an ionic solution, such as a solution of an ionic compound like sodium chloride (NaCl) in water, the compound dissociates into its constituent ions (Na+ and Cl-) due to the solvent's polarity. These ions are free to move and carry electric charge, allowing for the conduction of electricity. The greater the concentration of ions in the solution, the higher the conductivity.
On the other hand, covalent solutions typically involve molecules that are held together by covalent bonds, where electrons are shared between atoms rather than transferred as in ionic compounds. Covalent solutions, such as a solution of a molecular compound like glucose (C6H12O6) in water, do not dissociate into charged species to a significant extent. As a result, there are fewer freely moving charged particles in the solution, leading to lower conductivity compared to ionic solutions.
It's worth noting that there are exceptions where covalent compounds can form charged species and exhibit conductivity. For example, strong acids like hydrochloric acid (HCl) can ionize in water, producing hydrogen ions (H+) and chloride ions (Cl-), resulting in high conductivity. However, under normal conditions and at low concentrations, covalent solutions generally have lower conductivity compared to ionic solutions due to the differences in the nature of their dissolved species.