Is Ammonia (NH₃) a Strong or Weak Base?
Is Ammonia (NH₃) a strong or weak base?
Ammonia is a weak base that accepts a proton using its lone pair on nitrogen. When it accepts H+, it forms the ammonium ion (NH4+). As an acid, ammonia is extremely weak (pKa 38).
| Formula | NH₃ |
| Name | Ammonia |
| Category | Weak base |
| pKa | 38 |
| Conjugate | Ammonium ion (NH₄⁺) |
| Key Concept | Weak base, lone pair acceptor |
Definition
Ammonia is a Bronsted-Lowry base - it accepts a proton using the lone pair on nitrogen. NH3 + H2O <-> NH4+ + OH-. This equilibrium lies far to the left.
Acidic Proton / Active Site
Ammonia acts primarily as a base, not an acid. Its lone pair on nitrogen accepts a proton. The N-H bonds are very difficult to break (pKa 38 as an acid).
Conjugate Pair
When ammonia accepts a proton, it becomes NH4+ (ammonium ion, the conjugate acid). The ammonium ion is a weak acid with pKa 9.25.
Strength Classification
Ammonia is a weak base (Kb = 1.8 x 10^-5). It only partially accepts protons from water. Stronger bases like NaOH dissociate completely.
See acidic protons, conjugate base overlays, and pKa labels on interactive 3D molecules.
Explore Ammonia's Acid-Base Properties in 3DRelated Topics
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