1. What is pH and pOH?

pH and pOH are measures of acidity and basicity of aqueous solutions. pH represents the negative logarithm of hydrogen ion concentration, while pOH represents the negative logarithm of hydroxide ion concentration. The sum of pH and pOH always equals 14 at 25°C.

2. How Does the Calculator Work?

The calculator uses the following equations:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)
• \( pH \) — Measure of acidity (unitless)
• \( pOH \) — Measure of basicity (unitless)

Explanation: The logarithmic scale allows representation of a wide range of hydrogen ion concentrations in a manageable numerical format.

3. Importance of pH and pOH Calculation

Details: Accurate pH and pOH calculations are essential in chemistry, biology, environmental science, and industrial processes. They help determine solution acidity/basicity, predict chemical reactions, and maintain optimal conditions in various applications.

4. Using the Calculator

Tips: Enter hydrogen ion concentration in mol/L. The value must be greater than 0. The calculator will automatically compute both pH and pOH values.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C in aqueous solutions. This relationship is derived from the ion product of water (Kw = [H+][OH-] = 1.0 × 10^-14).

Q2: What are typical pH values for common substances?
A: Pure water has pH 7, lemon juice ~2.2, vinegar ~2.8, blood ~7.4, seawater ~8.1, bleach ~12.5.

Q3: How does temperature affect pH and pOH?
A: The ion product of water (Kw) changes with temperature, so the pH + pOH sum varies slightly from 14 at temperatures other than 25°C.

Q4: Can I calculate [H+] from pH?
A: Yes, using the inverse relationship: [H+] = 10^(-pH)

Q5: What are the limitations of pH calculation?
A: The calculation assumes ideal behavior and may not account for activity coefficients in concentrated solutions or non-aqueous solvents.