Weak bases

Definition

Weak bases are substances that partially ionize in water, producing a relatively small number of hydroxide ions ($OH^-$). They have a higher $pH$ compared to strong acids but do not completely dissociate in solution.

5 Must Know Facts For Your Next Test

1. Weak bases have a $K_b$ (base dissociation constant) value less than 1, indicating partial ionization.
2. Common examples include ammonia ($NH_3$) and methylamine ($CH_3NH_2$).
3. The $pH$ of weak base solutions is typically between 7 and 10.
4. In chemical reactions, weak bases often react with weak acids to form buffers.
5. Titration curves for weak bases show a gradual slope rather than a sharp change.

Review Questions

• What distinguishes a weak base from a strong base?
• Give two examples of common weak bases and their chemical formulas.
• Describe the behavior of weak bases in aqueous solutions in terms of ionization.

Related terms

Strong Base: A substance that completely ionizes in water, producing a large number of hydroxide ions ($OH^-$).

$K_b$ (Base Dissociation Constant): $K_b$ measures the extent to which a base dissociates into its ions in water.

$pH$: $pH$ is the measure of acidity or basicity of an aqueous solution, with lower values being acidic and higher values being basic.