1. What is OH- Concentration?

OH- concentration refers to the molar concentration of hydroxide ions in a solution. It is a fundamental parameter in acid-base chemistry that helps determine the basicity of a solution.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( [OH^-] \) — Hydroxide ion concentration (M)
• \( K_w \) — Ion product of water (1.0 × 10⁻¹⁴ M² at 25°C)
• \( [H^+] \) — Hydrogen ion concentration (M)

Explanation: This formula derives from the autoionization of water where \( K_w = [H^+][OH^-] \). Given any two of these values, the third can be calculated.

3. Importance of OH- Concentration Calculation

Details: Calculating OH- concentration is essential for understanding solution pH, determining basicity, and solving various chemical equilibrium problems in analytical chemistry and biochemistry.

4. Using the Calculator

Tips: Enter hydrogen ion concentration in moles per liter (M) and the ion product of water (typically 1.0 × 10⁻¹⁴ M²). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical value of Kw?
A: At 25°C, Kw is 1.0 × 10⁻¹⁴ M², but it varies with temperature.

Q2: How is OH- concentration related to pH?
A: pOH = -log[OH-], and pH + pOH = 14 at 25°C.

Q3: Can this calculator be used for acidic solutions?
A: Yes, the relationship holds for all aqueous solutions at equilibrium.

Q4: What units should be used for concentration?
A: Concentrations should be in moles per liter (Molarity, M).

Q5: Does temperature affect the calculation?
A: Yes, since Kw is temperature-dependent. For precise calculations, use the appropriate Kw value for the given temperature.