1. What is Hydroxide Ion Concentration?

The hydroxide ion concentration ([OH-]) is a measure of the amount of hydroxide ions in a solution. It's a fundamental parameter in chemistry that determines the basicity of a solution and is directly related to pH and pOH.

2. How Does the Calculator Work?

The calculator uses the following relationships:

Where:

• \( [OH^-] \) — Hydroxide ion concentration (molarity, M)
• \( pOH \) — Negative logarithm of hydroxide ion concentration
• \( pH \) — Measure of acidity/basicity of solution

Explanation: The calculator takes the hydroxide ion concentration as input and calculates both pOH and pH values, which are important for understanding solution properties.

3. Importance of [OH-] Calculation

Details: Knowing hydroxide ion concentration is essential for understanding solution chemistry, predicting reaction outcomes, and controlling chemical processes in laboratories and industries.

4. Using the Calculator

Tips: Enter the hydroxide ion concentration in molarity (M). The value must be positive. The calculator will automatically compute the corresponding pOH and pH values.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between [OH-] and pH?
A: pH and [OH-] are inversely related through pOH. As [OH-] increases, pOH decreases and pH increases (solution becomes more basic).

Q2: What are typical [OH-] values for common solutions?
A: Pure water at 25°C has [OH-] = 1×10⁻⁷ M. Basic solutions have higher [OH-], while acidic solutions have lower [OH-].

Q3: How is [OH-] measured experimentally?
A: [OH-] can be measured using pH indicators, pH meters, or through titration methods with standardized acid solutions.

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

Q5: Can [OH-] be calculated from pH?
A: Yes, using the relationship [OH-] = 10^(pH-14) at 25°C, since pH + pOH = 14 under standard conditions.