1. What is pH?

pH is a measure of the acidity or basicity of an aqueous solution. It is defined as the negative logarithm of the hydrogen ion concentration. The pH scale ranges from 0 to 14, with values below 7 indicating acidity, values above 7 indicating basicity, and 7 being neutral.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)

Explanation: The logarithmic scale means each whole pH value below 7 is ten times more acidic than the next higher value, and each whole pH value above 7 is ten times more basic than the next lower value.

3. Importance of pH Calculation

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

4. Using the Calculator

Tips: Enter the hydrogen 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 relationship between pH and [H⁺] concentration?
A: pH is the negative logarithm (base 10) of the hydrogen ion concentration. As [H⁺] increases, pH decreases, indicating higher acidity.

Q2: What are typical pH values for common substances?
A: Battery acid: ~0, Lemon juice: ~2, Pure water: 7, Baking soda: ~9, Ammonia: ~11, Bleach: ~13

Q3: How does temperature affect pH?
A: The pH of pure water decreases with increasing temperature due to increased ionization, though it remains neutral (equal H⁺ and OH⁻ concentrations).

Q4: What are the limitations of pH calculation from [H⁺]?
A: This calculation assumes ideal behavior and may not account for activity coefficients in concentrated solutions or complex buffer systems.

Q5: How is pH measured experimentally?
A: pH is typically measured using pH meters with glass electrodes, pH indicator papers, or chemical indicators that change color at specific pH values.