An aqueous solution of an acid conducts electricity because the acid molecules dissociate into ions when dissolved in water. This process, known as dissociation, involves the separation of the acid molecules into positively charged hydrogen ions (H+) and negatively charged ions, such as chloride ions (Cl-) in the case of hydrochloric acid. These ions, being charged particles, are free to move within the solution.
When an electric potential is applied across the solution, the positively charged hydrogen ions move toward the negatively charged electrode, while the negatively charged ions move toward the positively charged electrode. This movement of ions facilitated by water molecules allows the solution to conduct electricity.
Factors such as the concentration of the acid solution and temperature can influence the conductivity of the solution. For example, a more concentrated acid solution will have a higher concentration of ions, resulting in better conductivity. Similarly, a higher temperature can increase the kinetic energy of the ions, allowing them to move more freely and conduct electricity more efficiently.
In summary, an aqueous solution of an acid conducts electricity because the acid molecules dissociate into ions when dissolved in water, and these ions are free to move within the solution, allowing the solution to conduct electricity when an electric potential is applied.