1. What is pH?

pH is a measure of the acidity or basicity of an aqueous solution. It is defined as the negative logarithm (base 10) of the hydronium ion concentration [H₃O⁺]. The pH scale typically ranges from 0 to 14, with 7 being neutral.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( pH \) — pH value (dimensionless)
• \( [H_3O^+] \) — Hydronium ion concentration (mol/L)
• \( \log \) — Base-10 logarithm

Explanation: The formula calculates the negative logarithm of the hydronium ion concentration to determine the acidity level of a solution.

3. Importance of pH Calculation

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

4. Using the Calculator

Tips: Enter the hydronium ion concentration in moles per liter (mol/L). The value must be greater than 0. The calculator will compute the corresponding pH value.

5. Frequently Asked Questions (FAQ)

Q1: What does a pH value of 7 mean?
A: A pH of 7 indicates a neutral solution, where the concentration of H₃O⁺ ions equals the concentration of OH⁻ ions (10⁻⁷ mol/L each).

Q2: What is the pH range for acidic and basic solutions?
A: Acidic solutions have pH < 7, basic solutions have pH > 7, and neutral solutions have pH = 7.

Q3: Can pH be negative or greater than 14?
A: Yes, for very concentrated strong acids, pH can be negative, and for very concentrated strong bases, pH can exceed 14.

Q4: How is pH measured experimentally?
A: pH is typically measured using pH indicators, pH paper, or electronic pH meters with glass electrodes.

Q5: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C, where pOH = -log[OH⁻]. This relationship comes from the water dissociation constant K_w = [H⁺][OH⁻] = 10⁻¹⁴.