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pH Formula:
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The pH scale is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It ranges from 0 to 14, with 7 being neutral. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic.
The calculator uses the pH formula:
Where:
Explanation: The pH value is calculated as the negative base-10 logarithm of the hydrogen ion concentration in moles per liter.
Details: pH measurement is crucial in many fields including chemistry, biology, medicine, environmental science, and food science. It helps determine the acidity or alkalinity of substances which affects chemical reactions, biological processes, and material compatibility.
Tips: Enter hydrogen ion concentration in mol/L. The value must be greater than 0. For very small concentrations, scientific notation may be helpful (e.g., 1e-7 for 0.0000001).
Q1: What does a pH value of 7 mean?
A: A pH of 7 indicates a neutral solution, where the concentration of hydrogen ions equals the concentration of hydroxide ions (as in pure water at 25°C).
Q2: How does temperature affect pH?
A: The pH of neutral water changes with temperature. At higher temperatures, the pH of pure water decreases slightly due to increased ionization.
Q3: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C. pOH is calculated similarly to pH but uses hydroxide ion concentration instead of hydrogen ion concentration.
Q4: Can pH be negative or greater than 14?
A: Yes, for very concentrated strong acids, pH can be negative, and for very concentrated strong bases, pH can exceed 14. However, these are extreme cases.
Q5: Why is the pH scale logarithmic?
A: The logarithmic scale allows representation of the wide range of hydrogen ion concentrations found in solutions (from about 1 to 10^-14 mol/L) in a manageable 0-14 scale.