1. What is pH?

pH is a logarithmic measure of the hydrogen ion concentration in a solution. It indicates the acidity or alkalinity of a solution, with values below 7 being acidic and above 7 being alkaline.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)
• \( \log \) — Base-10 logarithm

Explanation: The pH scale is logarithmic, meaning each whole pH value below 7 is ten times more acidic than the next higher value.

3. Importance of pH Calculation

Details: pH measurement is crucial in chemistry, biology, medicine, environmental science, and many industrial processes. It affects chemical reactions, biological functions, and material properties.

4. Using the Calculator

Tips: Enter hydrogen ion concentration in mol/L. The value must be positive (concentration > 0). The result is dimensionless.

5. Frequently Asked Questions (FAQ)

Q1: What is the pH of pure water?
A: At 25°C, pure water has a pH of 7 (neutral) with [H+] = 1.0 × 10⁻⁷ mol/L.

Q2: What pH values are considered acidic and basic?
A: pH < 7 is acidic, pH = 7 is neutral, pH > 7 is basic (alkaline).

Q3: How does temperature affect pH?
A: The pH of neutral water changes with temperature (e.g., pH ≈ 6.81 at 37°C) because water's ionization changes with temperature.

Q4: What's the relationship between pH and pOH?
A: pH + pOH = 14 (at 25°C). pOH = -log[OH⁻].

Q5: Can pH be negative or greater than 14?
A: Yes, for very concentrated acids (negative pH) or bases (pH > 14), though these are rarely encountered outside specialized laboratory conditions.