1. What is pH Calculation from Hydroxide Ion Concentration?

pH calculation from hydroxide ion concentration is a fundamental chemical calculation that determines the acidity or basicity of a solution. The pH scale ranges from 0 to 14, with values below 7 indicating acidity, 7 being neutral, and values above 7 indicating basicity.

2. How Does the Calculator Work?

The calculator uses the pH calculation formula:

Where:

• \( [OH⁻] \) — Hydroxide ion concentration (mol/L)
• 14 — Constant representing pKw at 25°C (negative logarithm of water's ion product)
• log — Base-10 logarithm

Explanation: This formula calculates pH from hydroxide ion concentration using the relationship between pH, pOH, and the ion product of water (Kw = 10⁻¹⁴).

3. Importance of pH Calculation

Details: Accurate pH calculation is essential in chemistry, biology, environmental science, and many industrial processes. It helps determine solution properties, chemical reactivity, and biological compatibility.

4. Using the Calculator

Tips: Enter hydroxide ion concentration in mol/L. The value must be positive and greater than zero. The calculator will compute the corresponding pH value.

5. Frequently Asked Questions (FAQ)

Q1: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C. This relationship comes from the ion product of water: Kw = [H⁺][OH⁻] = 10⁻¹⁴.

Q2: What are typical pH values for common solutions?
A: Pure water has pH 7, lemon juice ~2.2, baking soda solution ~8.3, ammonia solution ~11.1.

Q3: Does temperature affect pH calculations?
A: Yes, the ion product of water (Kw) changes with temperature, so the constant 14 is only valid at 25°C.

Q4: What if I have hydrogen ion concentration instead?
A: If you have [H⁺], you can calculate pH directly using pH = -log[H⁺].

Q5: Are there limitations to this calculation?
A: This calculation assumes ideal behavior and may not be accurate for very concentrated solutions or non-aqueous solvents.