1. What is Activity of Hydrogen Ion?

Definition: The Activity of Hydrogen Ion is equal to the molar concentration of the dilute solution.

Purpose: It measures the effective concentration of hydrogen ions in a solution, which determines acidity.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( aH^+ \) — Activity of Hydrogen Ion (mol/m³)
• \( pH \) — Negative Log of Hydronium Concentration

Explanation: The pH value is the negative logarithm (base 10) of the hydrogen ion activity.

3. Importance of Hydrogen Ion Activity

Details: Hydrogen ion activity determines solution acidity, affects chemical reactions, and is crucial in biological systems.

4. Using the Calculator

Tips: Enter the pH value (typically between 0-14 for aqueous solutions). The calculator will compute the corresponding hydrogen ion activity.

5. Frequently Asked Questions (FAQ)

Q1: What does a lower pH value indicate?
A: Lower pH values indicate higher hydrogen ion activity and more acidic solutions.

Q2: How is pH related to hydrogen ion activity?
A: pH is the negative logarithm of hydrogen ion activity: pH = -log(aH+).

Q3: What's the hydrogen ion activity of pure water?
A: At 25°C, pure water has pH 7, so aH+ = 10^-7 mol/L.

Q4: Why use activity instead of concentration?
A: Activity accounts for non-ideal behavior in solutions where ions interact with each other.

Q5: What units are used for hydrogen ion activity?
A: The calculator uses mol/m³ (SI units), equivalent to mmol/L.