Question

Identify following substances which are underlined
A gas which does not conduct electricity in the liquid state but conducts electricity when dissolved in water

Answer 1

1. It is HCI which has a unique property that does not conduct electricity when it is in the gas phase since the gas phase of $\mathrm{HCl}$ is in the form of molecules and not in ionic form.
2. The anhydrous $\mathrm{HCI}$ gas does not conduct electricity. But Aqueous $\mathrm{HCI}$ conducts electricity since $\mathrm{HCl}$ completely dissociates in solution to form hydronium ion ${\mathrm{H}}_3{\mathrm{O}}^{+}$ and ${\mathrm{Cl}}^{-}$ions.
3. These ions are getting transported into opposite directions when potential electric junction is created by applying differential voltage,
4. Thus migration of these ions in opposite directions to each other allows electricity and thus becomes the conductor of electricity.