Theory:

Electrical conductivity of water:
  • Take water in a plastic container.
  • Use LED instead of bulb since LED glows even when a weak electric current flows through it.
  • Make a battery (a couple of cells) and connect its positive terminal to the longer lead of the LED. Put the negative terminal of the battery into the container contains water.
  • Put the shorter lead of the LED too into the water using a wire.
  • Make sure that both ends of the wire in the water do not touch and keep at least \(1\) cm distance.
water_cond.png
Experiment setup
 
In this experiment, we can see that the LED glows that means the circuit is closed; hence, the electricity passes through the water to complete the circuit. Thus, it proves that water is a good conductor of electricity.
Electrical conductivity of lemon juice:
Perform the above experiment replacing water in the container with lemon juice.
 
Lem_juice_cond.png
Experiment setup
 
LED glows since the lemon juice has an acid in it which is a good conductor of electricity.
 
The same result will be observed when we replace the lemon juice with vinegar.