1. What is pH?

pH is a measure of the acidity or basicity of an aqueous solution. It is defined as the negative logarithm (base 10) of the hydrogen ion (H₃O⁺) concentration. The pH scale typically ranges from 0 to 14, with 7 being neutral.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

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

Explanation: The formula calculates the negative base-10 logarithm of the hydrogen ion concentration to determine the acidity or basicity of a solution.

3. Importance of pH Calculation

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

4. Using the Calculator

Tips: Enter the H₃O⁺ 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 (very acidic) to 14 (very basic), with 7 being neutral.

Q2: How does pH relate to H₃O⁺ concentration?
A: pH is inversely related to H₃O⁺ concentration. As H₃O⁺ increases, pH decreases (more acidic). As H₃O⁺ decreases, pH increases (more basic).

Q3: What are typical pH values for common substances?
A: Lemon juice (pH ~2), vinegar (pH ~3), pure water (pH 7), baking soda solution (pH ~9), soapy water (pH ~10).

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 0-14 scale.

Q5: Can pH be negative or greater than 14?
A: Yes, for extremely concentrated acids pH can be negative, and for extremely concentrated bases pH can exceed 14, though these are rare in typical applications.