Strength of Acids and Bases:
All acids and bases do not ionize or dissociate to the same
extent. This leads to the statement that acids and bases are
not all of equal strength in producing H+ and OH-
ions in solution.
The terms "strong" and "weak" give an
indication of the strength of an acid or base. The terms strong
and weak describe the ability of acid and base solutions to conduct
electricity. If the acid or base conducts electricity strongly,
it is a strong acid or base. If the acid or base conducts electricity
weakly, it is a weak acid or base.
Demonstration of Acid and Base Conductivity:
The instructor will test the conductivity of various solutions
with a light bulb apparatus. The light bulb circuit is incomplete.
If the circuit is completed by a solution containing a large
number of ions, the light bulb will glow brightly indicating
a strong ability to conduct electricity as shown for HCl.
If the circuit is completed by a solution containing large
numbers of molecules and either no ions or few ions, the solution
does not conduct or conducts very weakly as shown for acetic
An acid or base which strongly conducts electricity contains
a large number of ions and is called a strong acid or base.
An acid or base which conducts electricity only weakly contains
only a few ions and is called a weak acid or base.