1. What is Ka and Kb?

Ka (acid dissociation constant) and Kb (base dissociation constant) are quantitative measures of the strength of acids and bases in solution. They are related through the ion product of water (Kw).

2. How Does the Calculator Work?

The calculator uses the relationship between Ka and Kb:

Where:

• \( K_a \) — Acid dissociation constant (M)
• \( K_b \) — Base dissociation constant (M)
• \( K_w \) — Ion product of water (1.0 × 10⁻¹⁴)

Explanation: This relationship allows calculation of the acid constant from its conjugate base constant using the fundamental water equilibrium constant.

3. Importance of Ka Calculation

Details: Knowing Ka values is essential for predicting acid strength, calculating pH of solutions, understanding buffer systems, and predicting the direction of acid-base reactions.

4. Using the Calculator

Tips: Enter the base dissociation constant (Kb) in molar units. The value must be positive and greater than zero. The calculator will compute the corresponding acid dissociation constant (Ka).

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between Ka and Kb?
A: For a conjugate acid-base pair, Ka × Kb = Kw, where Kw is the ion product of water (1.0 × 10⁻¹⁴ at 25°C).

Q2: What are typical values for Ka and Kb?
A: Strong acids have Ka > 1, weak acids have Ka < 1. Similarly for bases. Most biological acids have Ka values between 10⁻² and 10⁻¹⁰.

Q3: Does temperature affect Kw?
A: Yes, Kw changes with temperature. The value 1.0 × 10⁻¹⁴ is specific to 25°C. At other temperatures, different Kw values should be used.

Q4: Can this calculator be used for polyprotic acids?
A: This calculator is designed for monoprotic acid-base pairs. For polyprotic systems, each conjugate pair has its own Ka and Kb relationship.

Q5: What are pKa and pKb?
A: pKa = -log(Ka) and pKb = -log(Kb). The relationship becomes pKa + pKb = 14 at 25°C.