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pH Calculation Formula:
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The pH calculation from hydroxide concentration is a fundamental chemical calculation that determines the acidity or basicity of a solution based on the concentration of hydroxide ions [OH⁻]. This calculation is essential in various chemical and biological applications.
The calculator uses the pH calculation formula:
Where:
Explanation: The formula calculates pH from hydroxide ion concentration using the relationship between pH and pOH in aqueous solutions at 25°C, where pH + pOH = 14.
Details: Accurate pH calculation is crucial for understanding chemical reactions, biological processes, water quality assessment, and many industrial applications where pH control is essential.
Tips: Enter hydroxide concentration in mol/L. The value must be valid (concentration > 0). The calculator will compute the corresponding pH value.
Q1: Why is the formula pH = 14 + log[OH⁻]?
A: This formula derives from the relationship pH + pOH = 14, where pOH = -log[OH⁻], so pH = 14 - (-log[OH⁻]) = 14 + log[OH⁻].
Q2: What are typical pH values for common solutions?
A: Pure water has pH 7 (neutral), acidic solutions have pH < 7, and basic solutions have pH > 7. Strong bases can have pH values up to 14.
Q3: When is this calculation most accurate?
A: This calculation is most accurate for dilute aqueous solutions at 25°C. For concentrated solutions or different temperatures, additional corrections may be needed.
Q4: Are there limitations to this calculation?
A: This calculation assumes ideal behavior and may be less accurate for very concentrated solutions, non-aqueous solvents, or at temperatures significantly different from 25°C.
Q5: How does hydroxide concentration relate to acidity?
A: Higher hydroxide concentrations indicate more basic (alkaline) solutions with higher pH values, while lower concentrations indicate more acidic solutions with lower pH values.