1. What is Hydrogen Ion Concentration?

The hydrogen ion concentration ([H+]) is a measure of the acidity of a solution. It is inversely related to pH, with lower pH values corresponding to higher hydrogen ion concentrations. The relationship between pH and [H+] is logarithmic.

2. How Does the Calculator Work?

The calculator uses the fundamental pH formula:

Where:

• \( [H^+] \) — Hydrogen ion concentration in moles per liter (M)
• \( pH \) — The 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 biological systems.

4. Using the Calculator

Tips: Enter a pH value between 0 (very acidic) and 14 (very basic). The calculator will display the corresponding hydrogen ion concentration in both decimal and scientific notation.

5. Frequently Asked Questions (FAQ)

Q1: What is the [H+] of pure water?
A: Pure water at 25°C has a pH of 7, so [H+] = 10⁻⁷ M = 0.0000001 M.

Q2: How does temperature affect pH and [H+]?
A: The pH of pure water changes with temperature as the water dissociation constant changes, though [H+] always equals [OH⁻] in neutral water.

Q3: What's the [H+] in stomach acid?
A: Stomach acid typically has pH 1.5-3.5, corresponding to [H+] of about 0.03-0.003 M.

Q4: How small can [H+] get in strong bases?
A: At pH 14, [H+] = 10⁻¹⁴ M. The theoretical maximum pH in aqueous solutions is about 14-15.

Q5: Why use scientific notation for [H+]?
A: Because [H+] values span many orders of magnitude (from ~1 M to 10⁻¹⁴ M), scientific notation is more convenient than decimal notation.