Copper(II) sulfate solution is a good conductor of electricity primarily due to the presence of free ions in the solution. When copper(II) sulfate (CuSO4) is dissolved in water, it dissociates into copper ions (Cu2+) and sulfate ions (SO42-). These ions are charged particles that can move freely in the solution.
In any conductive solution, the movement of these charged ions allows electric current to flow. The more freely available ions there are, the better the solution can conduct electricity. In the case of copper(II) sulfate, both types of ions—copper and sulfate—contribute to the conduction of electricity.
In summary, copper(II) sulfate solution conducts electricity well because it contains free-moving ions that can carry electric charge throughout the solution.