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PH Scale 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, values less than 7 being acidic, and values greater than 7 being 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. This logarithmic scale means each whole pH value below 7 is ten times more acidic than the next higher value.
Details: pH calculation is essential in various fields including chemistry, biology, medicine, environmental science, and industrial processes. It helps determine the acidity or alkalinity of solutions, which affects chemical reactions, biological functions, and material properties.
Tips: Enter the 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 value of 7 indicates a neutral solution, where the concentration of hydrogen ions equals the concentration of hydroxide ions (1 × 10⁻⁷ mol/L at 25°C).
Q2: How does temperature affect pH?
A: The pH of pure water decreases with increasing temperature because the dissociation of water increases, but the solution remains neutral as [H⁺] = [OH⁻].
Q3: What is the relationship between pH and pOH?
A: pH + pOH = 14 at 25°C. pOH is calculated as -log₁₀[OH⁻], where [OH⁻] is the hydroxide 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 be greater than 14.
Q5: Why is the pH scale logarithmic?
A: The logarithmic scale allows a wide range of hydrogen ion concentrations (typically from about 1 to 10⁻¹⁴ mol/L) to be represented on a convenient scale of 0 to 14.