For electricity to flow there must be a flow of electrons or ions present in a system or medium. When electricity is passed in pure water, oxygen does not have d-orbitals or f-orbitals through which electrons may pass. In pure water there are no electrolytic substance, so no ions present in the pure water. Therefore electricity can not pass through pure water. Additionally; water cannot dissociate into OH- and H+ when electricity is passed through pure water.