1. What is pH and [H+]?

pH is a logarithmic measure of the hydrogen ion concentration in a solution. [H+] represents the molar concentration of hydrogen ions (protons) in solution. The relationship between pH and [H+] is inverse and logarithmic.

2. How Does the Calculator Work?

The calculator uses the fundamental pH formula:

Where:

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

Explanation: Each unit change in pH represents a 10-fold change in hydrogen ion concentration. For example, pH 3 has 10 times more H+ ions than pH 4.

3. Importance of [H+] Calculation

Details: Knowing the exact hydrogen ion concentration is crucial in chemistry, biology, medicine, and environmental science. It affects chemical reaction rates, enzyme activity, and biological systems.

4. Using the Calculator

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

5. Frequently Asked Questions (FAQ)

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

Q2: How does [H+] relate to acidity?
A: Higher [H+] means more acidic (lower pH). Each pH unit decrease means 10× more H+ ions.

Q3: What's the [H+] range for human blood?
A: Normal blood pH is 7.35-7.45, corresponding to [H+] of 3.55×10⁻⁸ to 4.47×10⁻⁸ mol/L.

Q4: Can pH be negative or >14?
A: While theoretically possible with extremely strong acids/bases, most practical measurements stay within 0-14.

Q5: How is pH measured experimentally?
A: Typically using pH meters with glass electrodes or pH indicator papers that change color.