1. What is the pH Calculation from CO₂?

This calculator estimates pH from dissolved CO₂ concentration using the relationship between carbonic acid formation and hydrogen ion concentration. It's based on the equilibrium between CO₂ and carbonic acid in aqueous solutions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( pH \) — pH value (dimensionless)
• \( [CO_2] \) — Dissolved CO₂ concentration (mol/L)
• \( K_1 \) — Equilibrium constant for CO₂ hydration (mol/L)

Explanation: The equation calculates pH based on the first dissociation constant of carbonic acid formed from dissolved CO₂ in water.

3. Importance of pH Calculation

Details: Accurate pH estimation from CO₂ is crucial for understanding acid-base balance in biological systems, environmental science, and industrial processes where CO₂ dissolution affects solution acidity.

4. Using the Calculator

Tips: Enter CO₂ concentration in mol/L and the K₁ constant value. The default K₁ value (4.3×10⁻⁷ mol/L) is provided but can be adjusted for specific conditions or temperatures.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical value for K₁?
A: At 25°C, K₁ is approximately 4.3×10⁻⁷ mol/L, but this value varies with temperature.

Q2: Why use this calculation instead of direct pH measurement?
A: This calculation is useful for predicting pH when only CO₂ concentration is known, or for theoretical modeling of acid-base systems.

Q3: What factors affect the accuracy of this calculation?
A: Temperature, ionic strength, and the presence of other buffering agents can affect the accuracy of the calculated pH.

Q4: Can this be used for seawater or other saline solutions?
A: For saline solutions, additional corrections for ionic strength may be needed for accurate pH estimation.

Q5: How does temperature affect the calculation?
A: The K₁ constant is temperature-dependent, so accurate calculations require the appropriate K₁ value for the specific temperature.