Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
A weak electrolyte is a substance that partially dissociates into ions when dissolved in water, resulting in a solution that conducts electricity poorly. Common examples include weak acids and weak bases.
5 Must Know Facts For Your Next Test
Weak electrolytes partially dissociate in water, meaning not all molecules break into ions.
The degree of ionization of weak electrolytes is less than 100%.
Examples of weak electrolytes include acetic acid (CH3COOH) and ammonia (NH3).
Weak electrolytes create solutions with low electrical conductivity compared to strong electrolytes.
The equilibrium between the undissociated molecules and the ions is characterized by an equilibrium constant (Ka or Kb).
Review Questions
Related terms
Strong Electrolyte: A substance that completely dissociates into ions when dissolved in water, resulting in high electrical conductivity.
Non-Electrolyte: A substance that does not produce ions when dissolved in water, hence it does not conduct electricity.
$K_a$ (Acid Dissociation Constant): $$K_a$$ is a measure of the strength of an acid in solution; it represents the equilibrium constant for its dissociation into hydrogen ions and conjugate base.