Experiment 20
Compare different water samples with a battery
and a LED

In  the previous experiment you have tested different water samples by leaving them to dry:
Distilled water did not leave any residue, salt and sugar water left crystals of different shapes.
Now you shall test the electric conductivities of  these water samples.
*  Puncture the stopper of a 5-ml vial by the shorter lead of a LED
*  Also puncture this stopper by an injection needle.
*  Connect the injection needle with the negative terminal of a 9-Volt battery.
* Touch the  longer lead of the diode to the positive terminal of the battery, but for only
   an - extremely short period for testing!-.

The light emitting diode (LED) shows light in salt water,
no light in distilled water or in sugar water.
Explanation:  Salt water is a good conductor for electricity, distilled water and sugar water are non-conductors.
Crystals from solutions:   Experiment W21                                                                       home