1. What is the pH = -log[H₃O⁺] Equation?

The pH = -log[H₃O⁺] equation is the fundamental definition of pH in chemistry. It quantifies the acidity or basicity of a solution by measuring the negative logarithm of the hydronium ion concentration.

2. How Does the Calculator Work?

The calculator uses the pH equation:

Where:

• \( pH \) — pH value (dimensionless)
• \( [H_3O^+] \) — Hydronium ion concentration (mol/L)

Explanation: The equation calculates the negative base-10 logarithm of the hydronium ion concentration to determine the pH value of a solution.

3. Importance of pH Calculation

Details: pH calculation is essential in chemistry, biology, environmental science, and many industrial processes. It helps determine the acidity or basicity of solutions, which affects chemical reactions, biological functions, and material properties.

4. Using the Calculator

Tips: Enter the hydronium ion concentration in mol/L. The value must be greater than 0. The calculator will compute the corresponding pH value.

5. Frequently Asked Questions (FAQ)

Q1: What is the range of pH values?
A: pH values typically range from 0 to 14, with 7 being neutral. Values below 7 indicate acidity, while values above 7 indicate basicity.

Q2: How is hydronium ion concentration related to pH?
A: pH is inversely related to hydronium ion concentration. As [H₃O⁺] increases, pH decreases, indicating higher acidity.

Q3: What are typical [H₃O⁺] values for common substances?
A: Pure water has [H₃O⁺] = 1×10⁻⁷ mol/L (pH=7). Lemon juice has [H₃O⁺] ≈ 0.01 mol/L (pH=2). Baking soda solution has [H₃O⁺] ≈ 1×10⁻⁸ mol/L (pH=8).

Q4: Are there limitations to this calculation?
A: This calculation assumes ideal conditions and may not account for temperature effects or ionic strength in complex solutions.

Q5: Can pH be calculated for very concentrated solutions?
A: For highly concentrated solutions, activity coefficients should be considered for accurate pH calculation, as the simple logarithmic relationship may not hold.