In the last section we discussed the nature of three important types of substances–acids, bases and salts. They show their typical properties in aqueous solutions. In this section we shall learn about their behaviour in such solutions.

Electrolytes and non­electrolytes
An electrolyte is a substance that conducts electric current through it in the molten state or through its solution. The most familiar electrolytes are acids, bases, and salts, which dissociate in their molten state when dissolved in such solvents as water or alcohol. When common salt (sodium chloride, NaCl) is dissolved in water, it forms an electrolytic solution, dissociating into positive sodium ions (Na⁺) and negative chloride ions (Cl^-;).
A non­electrolyte is a substance that does not conduct electric current through it in the molten state or through its solution. Non­electrolytes consist of molecules that bear no net electric charge and they do not dissociate in their molten state or in their solutions. Sugar dissolved in water maintains its molecular integrity and does not dissociate and it is a non­electrolyte.

Strong and weak electrolytes
In the last section we learned that electrolytes dissociate into ions in their solutions. Some electrolytes are completely dissociated into ions. They are called strong electrolytes. Sodium chloride, potassium hydroxide and hydrochloric acid are strong electrolytes. On the other hand some other electrolytes are dissociated only partially into ions. They are called weak electrolytes. Acetic acid and ammonium hydroxide are weak electrolytes.

Dissociation of acids and bases in water
In the last section we learned that some electrolytes are strong while others are weak. In this section we shall study more about dissociation processes that occur in aqueous solutions of acids and bases.