1. What is Hydrogen Ion Concentration?

The hydrogen ion concentration [H+] is a measure of the acidity of a solution. It is directly related to the pH value, which is a logarithmic scale used to specify the acidity or basicity of an aqueous solution.

2. How Does the Calculator Work?

The calculator uses the fundamental pH equation:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)
• \( pH \) — pH value (dimensionless, range 0-14)

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 and [H+]

Details: Hydrogen ion concentration is crucial in chemistry, biology, medicine, and environmental science. It affects enzyme activity, chemical reaction rates, and the behavior of many biological systems.

4. Using the Calculator

Tips: Enter a pH value between 0 and 14. The calculator will compute the corresponding hydrogen ion concentration in moles per liter (mol/L), displayed in both decimal and scientific notation.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and [H+]?
A: pH is the negative logarithm (base 10) of the hydrogen ion concentration: pH = -log[H+].

Q2: What is a neutral pH?
A: At 25°C, neutral pH is 7.0, corresponding to [H+] = 1.0 × 10⁻⁷ mol/L.

Q3: How does temperature affect pH?
A: The neutral pH changes with temperature due to changes in water's self-ionization. At higher temperatures, neutral pH is slightly less than 7.

Q4: What are typical [H+] values for common substances?
A: Stomach acid: ~10⁻¹ mol/L (pH ~1), pure water: 10⁻⁷ mol/L (pH 7), bleach: ~10⁻¹³ mol/L (pH ~13).

Q5: Why use scientific notation for [H+]?
A: Because [H+] values typically span many orders of magnitude (from ~1 to 10⁻¹⁴ mol/L), scientific notation makes them easier to compare and understand.