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, 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 in moles per liter (M)
• \( pH \) — 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 chemical reactions, enzyme function, and the health of aquatic ecosystems.

4. Using the Calculator

Tips: Enter a pH value between 0 (very acidic) and 14 (very basic). The calculator will compute the corresponding hydrogen ion concentration in molarity (M).

5. Frequently Asked Questions (FAQ)

Q1: What is the [H+] of pure water at 25°C?
A: Pure water has a pH of 7, so [H+] = 10⁻⁷ = 0.0000001 M or 1 × 10⁻⁷ M.

Q2: How does [H+] relate to acidity?
A: Higher [H+] means more acidic. A solution with pH 3 has 10 times more H+ than pH 4 and 100 times more than pH 5.

Q3: What's the [H+] range for typical solutions?
A: From 1 M (pH 0) to 10⁻¹⁴ M (pH 14). Most biological systems operate between pH 6.5-7.5.

Q4: Can pH be negative?
A: Yes, for very strong acids where [H+] > 1 M, though such solutions are rare and require special handling.

Q5: How is pH measured experimentally?
A: Typically with a pH meter using a glass electrode, or with pH indicator papers for less precise measurements.