1. What Is Ka From Concentration And Dissociation Degree?

The acid dissociation constant (Ka) is a quantitative measure of the strength of an acid in solution. This calculator determines Ka from the initial concentration and degree of dissociation of a weak acid.

2. How Does The Calculator Work?

The calculator uses the formula:

Where:

• \( K_a \) — Acid dissociation constant
• \( C \) — Initial concentration of the acid (M)
• \( \alpha \) — Degree of dissociation (decimal between 0 and 1)

Explanation: This formula applies to weak acids where the degree of dissociation is small and the approximation is valid. It relates the equilibrium constant to the initial concentration and extent of dissociation.

3. Importance Of Ka Calculation

Details: Ka values are crucial for understanding acid strength, predicting pH of solutions, and calculating buffer capacities. They are fundamental in chemical equilibrium studies and analytical chemistry.

4. Using The Calculator

Tips: Enter concentration in molarity (M) and dissociation degree as a decimal (e.g., 0.05 for 5%). Ensure concentration > 0 and dissociation degree between 0 and 1 (exclusive).

5. Frequently Asked Questions (FAQ)

Q1: What is the range of typical Ka values?
A: Ka values range from about 10⁻¹⁰ for very weak acids to 10¹⁰ for very strong acids. Most weak acids have Ka values between 10⁻² and 10⁻¹⁰.

Q2: How is dissociation degree related to pH?
A: For monoprotic weak acids, pH = -log(√(Ka × C)) when α is small. The dissociation degree can be calculated from pH using α = 10^(-pKa + pH).

Q3: When is this formula not applicable?
A: This formula assumes α << 1. For stronger acids or concentrated solutions where α approaches 1, more complex equilibrium calculations are needed.

Q4: What is pKa and how is it related to Ka?
A: pKa = -log₁₀(Ka). It provides a more convenient scale where lower pKa values indicate stronger acids.

Q5: Can this be used for polyprotic acids?
A: This specific formula is for monoprotic acids. Polyprotic acids require separate Ka calculations for each dissociation step.