Question

Sea water is better conductor of electricity then tap water why

Answer 1

because sea water contains salt in it salt is a good conductor wereas tap water is pure so it is not a better conductor of electricity

Answer 2

Here is your answer:
The conductivity of water depends on the concentration of dissolved ions in solution.Sea water has a relatively large number of Sodium and Chloride ions and has a conductivity of around 5S/m. This is because the Sodium Chloride salt dissociates into ions. Hence sea water is about a million times more conductive than fresh water.
Hope it helps.