ChemMatters February 1988 (page 13-15)
“Water itself doesn't conduct electricity; it's the minerals in it that conduct the electricity, not the water.” * When a tap water was produced to an electrical device with a pair of probes and a light bulb, the bulb immediately beamed. The reason for this to happen is the presence of minerals in water. However, when this was tested with distilled water, it was observed that the light bulb did not beam. This proves that water by itself is not a conductor of electricity, but it’s the minerals. * When a tap water was tested using a precipitator, the tap water took on a yellow hue and in minutes a brownish scum covered the surface of the water. However, after a thorough experiment, the reason for the appearance of this brownish scum was discovered. The scummy precipitate was formed of ions that came directly from the precipitator, not from the tap water. * When the current is on, the iron electrode becomes the anode and the iron is oxidized: Fe(s) Fe3+ (aq) + 3e-
The aluminum electrode was the cathode. Here, water was decomposed to from hydrogen gas and hydrogen ions: 2H2O (1) + 2e- H2 (g) + 2OH-(aq)
In conclusion, all the scum formed was due to the “precipitator”, not ions in the tap water. Related questions:
1. Why Distilled Water Does Not Conduct Electricity
Distilled water is water purified of any contaminants and pure water does not conduct electricity. This is because an H2O molecule has no charge and no need to swap electrons. However, salt water is considered a good electricity conductor and this is due to the ions within it.
2. Why doesn’t carbon take part in electrolysis reactions? Carbon is a conductor of electricity, but it is relatively inert. This is the reason why carbon does not take part in electrolysis reactions.
3. Is Tap Water Containing Minerals Safe?
Tap water containing minerals is generally safe to drink. There has been some research to...