The purpose of a switch in a series circuit is to make it easy to open or close the electrical circuit, turning the flow of electricity on or off. A light bulb in a series circuit is used to determine whether or not electricity is flowing.
The answer is (3) CH3COOH. CH3COOH is a acid. It can ionized in water. So the solution can conduct an electric current. And the other three can not be ionized in water.
