Ph Calculator
Calculate the pH of a solution given the hydrogen ion concentration or the hydroxide ion concentration.
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isCalculator Editorial Team
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How to use this tool?
How to Use the pH Calculator
- Select Input Type: Choose whether your concentration is for hydronium ions ([H₃O⁺]) or hydroxide ions ([OH⁻]) from the dropdown menu.
- Enter Concentration: Type a positive number (e.g.,
1e-7for 1×10⁻⁷ mol/L) into the "Concentration" field. Use scientific notation if needed. The value must be greater than zero. - Calculate: Click the "Calculate" button. The result will show the pH value (rounded to 4 decimal places) along with step-by-step formula explanation.
Notes:
- For [H₃O⁺] input: pH = -log₁₀([H₃O⁺])
- For [OH⁻] input: pH = 14 - pOH, where pOH = -log₁₀([OH⁻])
- All concentrations must be in mol/L (molarity).
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Frequently Asked Questions
pH is a measure of the acidity or basicity of an aqueous solution. It is defined as the negative logarithm (base 10) of the hydrogen ion concentration.
Select whether you know the concentration of H₃O⁺ or OH⁻, enter the concentration in mol/L, and click Calculate. The pH will be displayed.
The pH scale ranges from 0 to 14. A pH less than 7 is acidic, pH equal to 7 is neutral, and pH greater than 7 is basic.