1. What is pH Calculation?

pH calculation determines the acidity or basicity of a solution by measuring the concentration of hydronium ions (H₃O⁺). The pH scale ranges from 0 to 14, with values below 7 indicating acidity, 7 being neutral, and above 7 indicating basicity.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( [\text{H}_3\text{O}^+] \) — Hydronium ion concentration (mol/L)
• \( \log \) — Base-10 logarithm

Explanation: The negative logarithm of the hydronium ion concentration gives the pH value, which indicates the acidity level of the solution.

3. Importance of pH Calculation

Details: Accurate pH measurement is crucial in various fields including chemistry, biology, environmental science, and medicine. It helps in understanding chemical reactions, biological processes, and environmental conditions.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

Q1: What does a pH value of 7 mean?
A: A pH value of 7 indicates a neutral solution, where the concentration of H₃O⁺ ions equals that of OH⁻ ions (10⁻⁷ mol/L each).

Q2: How is pH related to pOH?
A: pH and pOH are related by the equation: pH + pOH = 14 at 25°C. This relationship comes from the ion product of water (K_w = 10⁻¹⁴).

Q3: Can pH be negative or greater than 14?
A: Yes, for very concentrated strong acids, pH can be negative, and for very concentrated strong bases, pH can exceed 14. However, these are extreme cases.

Q4: Why use logarithmic scale for pH?
A: The logarithmic scale compresses the wide range of H₃O⁺ concentrations (from 1 to 10⁻¹⁴ mol/L) into a more manageable scale of 0-14.

Q5: How does temperature affect pH?
A: Temperature affects the autoionization of water (K_w changes), which means the neutral point (pH = 7) only applies at 25°C. At other temperatures, neutral pH differs.