Is Hydrazine (N₂H₄) a Strong or Weak Base?
Is Hydrazine (N₂H₄) a strong or weak base?
Hydrazine (H2N-NH2) is a weak diprotic base - both nitrogen atoms have lone pairs that can accept protons. It is weaker than ammonia because the adjacent nitrogen is electron-withdrawing.
| Formula | N₂H₄ |
| Name | Hydrazine |
| Category | Weak base |
| pKa | 8.1 |
| Conjugate | Hydrazinium ion (N₂H₅⁺) |
| Key Concept | Diprotic base |
Definition
Hydrazine has two -NH2 groups connected by an N-N bond. Each nitrogen can accept a proton, making it a diprotic base.
Acidic Proton / Active Site
Hydrazine acts as a base, not an acid. Both nitrogen lone pairs can accept protons, though the first protonation is much easier than the second.
Conjugate Pair
N2H4 + H+ -> N2H5+ (first protonation). N2H5+ + H+ -> N2H6^2+ (second, much weaker). The adjacent NH3+ group makes the second protonation very difficult.
Strength Classification
Kb1 = 1.3 x 10^-6, weaker than ammonia. The second nitrogen is electron-withdrawing, reducing electron density on each N compared to ammonia.
See acidic protons, conjugate base overlays, and pKa labels on interactive 3D molecules.
Explore Hydrazine's Acid-Base Properties in 3DRelated Topics
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