1. What is the Ion Product Equation?

The ion product equation \( K_w = [H^+][OH^-] = 10^{-14} \) describes the equilibrium constant for water autoionization at 25°C. It relates the concentrations of hydrogen ions and hydroxide ions in aqueous solutions.

2. How Does the Calculator Work?

The calculator uses the fundamental relationships:

Where:

• \( [H^+] \) — Hydrogen ion concentration (mol/L)
• \( [OH^-] \) — Hydroxide ion concentration (mol/L)
• \( pH \) — Negative logarithm of hydrogen ion concentration
• \( pOH \) — Negative logarithm of hydroxide ion concentration

3. Importance of pH and pOH Calculations

Details: pH and pOH calculations are essential in chemistry, biology, environmental science, and many industrial processes for understanding acidity, basicity, and chemical equilibrium in aqueous solutions.

4. Using the Calculator

Tips: Enter any one known value (H+ concentration, OH- concentration, pH, or pOH) and the calculator will compute the other three values. Values must be within valid ranges (pH and pOH: 0-14, concentrations: positive values).

5. Frequently Asked Questions (FAQ)

Q1: What does Kw = 10⁻¹⁴ represent?
A: This is the ion product of water at 25°C, representing the equilibrium constant for water's autoionization: 2H₂O ⇌ H₃O⁺ + OH⁻

Q2: How are pH and pOH related?
A: pH + pOH = 14 at 25°C. This relationship holds true for all aqueous solutions at this temperature.

Q3: What is considered neutral pH?
A: pH = 7 is neutral at 25°C, where [H⁺] = [OH⁻] = 10⁻⁷ mol/L.

Q4: Does temperature affect these calculations?
A: Yes, Kw changes with temperature. The relationship pH + pOH = 14 is specific to 25°C.

Q5: What are typical pH ranges?
A: Acidic solutions: pH < 7, Basic solutions: pH > 7, Neutral: pH = 7. Most biological systems operate within pH 6-8.