Why is there a difference in conductivity for distilled water and tap water?

Question

Hi guys, just wanted to konw why tap water conducts electricity, while distilled water does not conduct any electricity. It has something to do with bonds, like ionic, covalent (polar/non-polar). Any ideas? Thanks :)

Answer 1

Tap water has come from a well or an outdoor water source and has ions from that source. It has ions from piping. It has ions from being hard water.

Distilled water has been boiled and the steam condensed, all the ions stayed behind.

Answer 2

Tap water will likely have disolved salts in it. That means ions are floating around. Conductivity tests are an indication of the amount of disolved salts.