1. What is pH Calculation?

pH calculation determines the acidity or basicity of a solution. For strong acids like HCl, the pH is calculated directly from the concentration of hydrogen ions [H⁺] using the formula pH = -log([H⁺]).

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)
• For strong acid HCl: \( [H^+] = C \) (concentration of HCl)

Explanation: The pH scale ranges from 0 to 14, with values below 7 indicating acidic solutions, 7 being neutral, and values above 7 indicating basic solutions.

3. Importance of pH Calculation

Details: pH measurement is crucial in chemistry, biology, environmental science, and many industrial processes. It helps determine the acidity of solutions, which affects chemical reactions, biological functions, and environmental conditions.

4. Using the Calculator

Tips: Enter the concentration of HCl in mol/L. The calculator will compute both the pH value (dimensionless) and the hydrogen ion concentration.

5. Frequently Asked Questions (FAQ)

Q1: Why is HCl considered a strong acid?
A: HCl completely dissociates in water, producing H⁺ and Cl⁻ ions, making it a strong acid with [H⁺] equal to its concentration.

Q2: What is the pH range for acidic solutions?
A: Acidic solutions have pH values less than 7. The lower the pH value, the stronger the acidity.

Q3: How does concentration affect pH?
A: For strong acids, as concentration increases, pH decreases (becomes more acidic). Each tenfold increase in concentration decreases pH by 1 unit.

Q4: Can this calculator be used for weak acids?
A: No, this calculator is specifically designed for strong acids like HCl. Weak acids require different calculations involving acid dissociation constants.

Q5: What are typical pH values for common substances?
A: Battery acid: ~0.5, Lemon juice: ~2.0, Vinegar: ~3.0, Pure water: 7.0, Baking soda: ~8.3, Ammonia: ~11.0.