Testing Electrical Conductivity of Liquids
With the help of a simple experiment, we can determine which liquids are good conductors of electricity and which are bad conductors.
Experimental Set-Up and Procedure
For this experiment, we require a dry cell, three insulated copper wires, a container and a bulb. This is what the set-up looks like:
For the experiment to work, the circuit has to be completed. Adding a liquid to the container completes the circuit. The free ends of the copper wires are immersed inside the liquid. It is important that the distance between the wires is less than one centimetre and at the same time, they should not touch each other.
The light bulb is the indicator of electric current flowing through the liquid. Thus, if the bulb glows brightly, the liquid is a good conductor of electricity.
On the other hand, if it doesn’t glow brightly, the liquid is a poor conductor of electricity.
It is also important that once a liquid is tested, the container and the wires are thoroughly cleaned before pouring in the next liquid.
The liquids that will be tested are tap water, lemon juice, vinegar, distilled water and saltwater.
Observation and Conclusion
| Liquid in container | Observation | Conclusion |
| Tap water | Bulb glows brightly | Good conductor |
| Lemon juice | Bulb glows brightly | Good conductor |
| Vinegar | Bulb glows, but not brightly | Poor conductor |
| Distilled water | Bulb glows, but not brightly | Poor conductor |
| Distilled water with salt | Bulb glows brightly | Good conductor |
| (Saltwater) |
 It is important to note that the faint glowing of the bulb doesn’t always indicate that the conductor is poor. The cell in the circuit may be weak or the bulb itself may be faulty. There is a chance that the current flowing in the circuit is not adequate for the bulb to glow.
Summary
| Testing Electrical Conductivity of Liquids |
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