Why does distilled water not conduct electricity, whereas rainwater does ?

Distilled water does not conduct electricity because it does not contain any ionic compound (like acids, bases or salts) dissolved in it. Rainwater, while falling to the earth through the atmosphere, dissolves an acidic gas carbon dioxide from the air and forms carbonic acid (H2CO3). Carbonic acid provides hydrogen ions, H+ (aq) and carbonate ions, CO(aq)32to rainwater. Hence, due to the presence of carbonic acid which provides ions to rainwater, the rainwater conducts electricity.