Conjugate Säure-Basen Rechner — Formel
## Conjugate Acid-Base Relationship
### Formula
**Ka × Kb = Kw**
Therefore:
- **Ka = Kw / Kb** (find Ka of conjugate acid from Kb of base)
- **Kb = Kw / Ka** (find Kb of conjugate base from Ka of acid)
At 25°C, Kw = 1.0 × 10⁻¹⁴. This means pKa + pKb = 14.
### Formula
**Ka × Kb = Kw**
Therefore:
- **Ka = Kw / Kb** (find Ka of conjugate acid from Kb of base)
- **Kb = Kw / Ka** (find Kb of conjugate base from Ka of acid)
At 25°C, Kw = 1.0 × 10⁻¹⁴. This means pKa + pKb = 14.
Lösungsbeispiel
Ammonia has Kb = 1.8 × 10⁻⁵. Find Ka of its conjugate acid NH₄⁺.
- Ka = Kw / Kb
- Ka = 1.0 × 10⁻¹⁴ / 1.8 × 10⁻⁵
- Ka = 5.56 × 10⁻¹⁰
- pKa = -log₁₀(5.56 × 10⁻¹⁰) = 9.26