Electrolytes

All ionic substances and highly polar non-ionic compounds, which when dissolved in water give ions, are electrolytes. These electrolytes can be salts, acids and bases. Some of the characteristic features of these electrolytes are:

• They conduct electricity in their molten states or when present in the form of their solutions in any polar solvent.

• The solution of an electrolyte on the whole is electrically neutral.

• Electrolytes, when dissolved in a solvent of high dielectric constant such as water form ionic solutions involving the formation of cations and anions.

• The conducting power of an electrolytic solution depends on the nature of the electrolyte, its concentration and temperature.

Depending on their conducting power electrolytes can be classified as:

Strong electrolyte

These electrolytes give highly conducting solutions when dissolved in water because they are completely dissociated into ions. For example, HCl, NaCl, Na₂SO₄, KNO₃, H₂SO₄, NH₄Cl etc.

Weak electrolyte

Substances, which give poorly conducting solutions when dissolved in water because they are ionized to a very small extent are called as weak electrolytes. For example, NH₃, CH₃COOH, H₂CO₃, organic bases etc.