1. What is Ka Formula From pH?

The Ka formula from pH calculates the acid dissociation constant (Ka) from pH measurements. Ka represents the equilibrium constant for acid dissociation and indicates the strength of an acid in solution.

2. How Does the Calculator Work?

The calculator uses the following formulas:

Where:

• \( Ka \) — Acid dissociation constant (unitless)
• \( pH \) — Negative logarithm of hydrogen ion concentration
• \( pKa \) — Negative logarithm of Ka value
• \( [H⁺] \) — Hydrogen ion concentration

Explanation: The pH scale is logarithmic, so converting pH to Ka involves using the inverse logarithmic relationship to determine the acid dissociation constant.

3. Importance of Ka Calculation

Details: Ka values are crucial for understanding acid strength, predicting acid-base behavior in chemical reactions, and calculating buffer capacities in biological and chemical systems.

4. Using the Calculator

Tips: Enter pH value between 0 and 14. The calculator will automatically compute both Ka and pKa values. Lower pH values indicate stronger acids with higher Ka values.

5. Frequently Asked Questions (FAQ)

Q1: What does Ka represent?
A: Ka represents the equilibrium constant for acid dissociation. Higher Ka values indicate stronger acids that dissociate more completely in water.

Q2: What is the relationship between Ka and pKa?
A: pKa is the negative logarithm of Ka (pKa = -log Ka). Lower pKa values indicate stronger acids.

Q3: What are typical Ka values for common acids?
A: Strong acids have Ka > 1, weak acids have Ka < 1. For example, acetic acid Ka ≈ 1.8×10⁻⁵, hydrochloric acid Ka ≈ 10⁷.

Q4: Can this calculator be used for bases?
A: No, this calculator is specifically for acids. For bases, you would calculate Kb from pOH or use the relationship Ka × Kb = Kw.

Q5: What are the limitations of this calculation?
A: This assumes ideal conditions and monoprotic acids. For polyprotic acids or non-ideal solutions, additional calculations are needed.