Question

Pure water does not conduct electricity because it is?
(A) Neutral
(B) Readily decomposed
(C) Almost unionised
(D) Completely unionised

Answer 1

Hint :It is important to know that , Electrical conduction is the movement of electrically charged particles through a transmission medium which means conduction requires free ions. The movement of ions can form an electric current in response to an electric field.

Complete Step By Step Answer:
All substances are made up of atoms and they have charged particles called electrons and protons. Electrons are negatively charged and protons are positively charged. Electricity in all forms is a result of this charge on the fundamental particles present. Conduction of electricity is the movement of the charged particles in an organized manner in a material. When charged particles move in an orderly fashion within a material, we get an electric current.
The creation of ions in a solution is largely decided by the nature of chemical bonds present between the atoms of the compound. Covalent compounds are usually made from non-metal elements which are bonded by bonds formed by sharing of electrons. Since electrons are shared in covalent bonds they cannot separate into charged ions in a solution easily. Ionic compounds are compounds made of charged particles. The positive ions are formed by metals having lost one or more electrons whereas negative ions are formed by nonmetals gaining one or more extra electrons. Positive and negative ions attract each other and combine with each other to yield ionic compounds and they are separated easily to conduct electricity.
The concentration of ions in pure water is very less and is almost unionised, thus does not conduct electricity.
Correct option is (C).

Note :
For pure water Kw = [H+][OH- ]=10 raised to power -14
 ∴[H+]=[OH-]=10 raise to power -7M
We can see the concentration of ions is very less as water is almost unionised, therefore it does not conduct electricity.