Summary:
- Acids are classified as either strong or weak, based on their ionization in water.
- A strong acid is an acid which is completely ionized in an aqueous solution.
- Weak acids are only slightly ionized.
- An acid ionization constant is the equilibrium constant for the ionization of an acid.
- Strong acids are essentially 100% ionized, and so the concentration of the acid in the denominator is nearly zero.
- For this reason, values are generally reported for weak acids only.