Question

A gas which does not conduct electricity in the liquid state but conducts electricity when dissolved in water is :

• A. $HCl$.
• B. $H_2$.
• C. $S{O}_2$.
• D. $C{l}_2$.

Answer 1

Answer: (A)

$HCl$.

It is HCl having a unique property which does not conduct electricity when it is in gas phase since the gas phase of HCl is in the form of molecules and not in ionic form, the anhydrous HCl gas does not conduct electricity.

But HCl solution or Aquous $HCl$ conducts electricity since HCl completely dissociates in solution to form hydronium $H_3{O}^{+}$ and $C{l}^{-}$ ions which are getting transported into opposite direction when potential electric junction is created by applying differential voltage, thus migration of these ions in opposite directions to each other allows electricity and thus becomes conductor of electricity.