1. What is the pH Calculation for KOH?

The pH calculation for potassium hydroxide (KOH), a strong base, is based on the relationship between hydroxide ion concentration and pH. For strong bases that completely dissociate, pH can be directly calculated from the concentration.

2. How Does the Calculator Work?

The calculator uses the pH equation for strong bases:

Where:

• \( C \) — Concentration of KOH solution (mol/L)
• 14 — pKw value at 25°C (water ion product)

Explanation: Since KOH is a strong base that completely dissociates, [OH⁻] = C. Therefore, pOH = -log[OH⁻] = -log C, and pH = 14 - pOH = 14 + log C.

3. Importance of pH Calculation

Details: Accurate pH calculation is essential for chemical reactions, biological systems, industrial processes, and laboratory experiments where precise pH control is required.

4. Using the Calculator

Tips: Enter the concentration of KOH solution in mol/L. The value must be greater than 0. The calculator will compute the pH value at 25°C.

5. Frequently Asked Questions (FAQ)

Q1: Why is there a plus sign in the formula instead of minus?
A: For strong bases, pH = 14 + log C because pOH = -log[OH⁻] and pH = 14 - pOH = 14 + log C (since log C is negative for C < 1).

Q2: What is the pH range for KOH solutions?
A: For typical laboratory concentrations (0.001-1 M), pH ranges from approximately 11 to 14. Higher concentrations yield pH values closer to 14.

Q3: Does temperature affect the calculation?
A: Yes, the pKw value changes with temperature. This calculator uses pKw = 14, which is accurate for 25°C.

Q4: Can this calculator be used for other strong bases?
A: Yes, the same formula applies to any strong base that completely dissociates, such as NaOH, LiOH, etc.

Q5: What about very concentrated KOH solutions?
A: For concentrations above 1 M, activity coefficients become important and the simple calculation may not be accurate due to ionic strength effects.