pKa计算器
计算酸的pKa值，衡量酸的强度。
pKa
4.76
公式
## How to Calculate pKa ### Formula **pKa = −log₁₀(Ka)** Where: - **pKa** = negative base-10 logarithm of Ka - **Ka** = acid dissociation constant A lower pKa indicates a stronger acid. pKa is more convenient than Ka for comparing acid strengths.
计算示例
Acetic acid has Ka = 1.75 × 10⁻⁵.
- 01pKa = -log₁₀(Ka)
- 02pKa = -log₁₀(1.75 × 10⁻⁵)
- 03pKa = 4.76
常见问题
What does pKa tell you?
pKa indicates acid strength on a logarithmic scale. Lower pKa means stronger acid. Each unit decrease in pKa represents a 10-fold increase in acid strength.
Can pKa be negative?
Yes. Strong acids like HCl have negative pKa values (around -7), meaning they dissociate almost completely.
How do I convert pKa back to Ka?
Ka = 10^(-pKa). For example, pKa = 4.76 gives Ka = 10^(-4.76) = 1.74 × 10⁻⁵.
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