Weak Base
A base that accepts protons only partially in aqueous solution, establishing an equilibrium.
Formula / equation
B + H₂O ⇌ BH⁺ + OH⁻
Unit
mol/L
In depth
A weak base generates far less hydroxide than its concentration would suggest, so its solutions are only mildly alkaline. Amines are the most important family, and their basicity is increased by electron-donating alkyl groups and reduced by aromatic rings that delocalise the lone pair.
Examples in the real world
Ammonia, methylamine, pyridine and the carbonate ion; aniline is very weak because its lone pair is delocalised.