1. What is Hydroxide Ion Concentration?

The hydroxide ion concentration ([OH-]) is a measure of the alkalinity of a solution. It's inversely related to pOH, which is the negative logarithm of the hydroxide ion concentration.

2. How Does the Calculator Work?

The calculator uses the fundamental relationship between pOH and hydroxide ion concentration:

Where:

• \( [OH^-] \) — Hydroxide ion concentration (mol/L)
• \( pOH \) — Negative logarithm of hydroxide ion concentration (dimensionless)

Explanation: This logarithmic relationship means each unit change in pOH corresponds to a tenfold change in hydroxide ion concentration.

3. Importance of [OH-] Calculation

Details: Knowing hydroxide ion concentration is essential for understanding solution pH, chemical equilibrium, and many biological and industrial processes.

4. Using the Calculator

Tips: Enter pOH value between 0 and 14. The calculator will compute the corresponding hydroxide ion concentration in mol/L.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and pOH?
A: In aqueous solutions at 25°C, pH + pOH = 14. This relationship allows conversion between pH and pOH.

Q2: What are typical [OH-] values?
A: Neutral water at 25°C has [OH-] = 1×10⁻⁷ mol/L. Basic solutions have higher [OH-], acidic solutions have lower.

Q3: How does temperature affect [OH-]?
A: The ion product of water (Kw) changes with temperature, affecting the pH/pOH relationship.

Q4: What's the difference between [OH-] and alkalinity?
A: [OH-] measures free hydroxide ions, while alkalinity measures a solution's capacity to neutralize acids.

Q5: When is pOH more useful than pH?
A: pOH is particularly useful when working with basic solutions or hydroxide ion concentrations.