1. What is pH?

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 [H+]. The pH scale ranges from 0 (very acidic) to 14 (very basic), with 7 being neutral.

2. How Does the Calculator Work?

The calculator uses the pH formula:

Where:

• \( pH \) — pH value (unitless)
• \( [H^+] \) — Hydrogen ion concentration in molarity (M)

Explanation: The logarithmic nature of the pH scale means each whole pH value below 7 is ten times more acidic than the next higher value.

3. Importance of pH Calculation

Details: pH measurement is crucial in chemistry, biology, medicine, and environmental science. It affects chemical reactions, biological functions, and the behavior of many substances.

4. Using the Calculator

Tips: Enter the hydrogen ion concentration in molar units (M). The value must be positive. For very small concentrations, scientific notation may be needed.

5. Frequently Asked Questions (FAQ)

Q1: What is a neutral pH?
A: A pH of 7 is considered neutral at 25°C (77°F), which is the temperature at which water dissociates equally into H+ and OH- ions.

Q2: What's the pH of pure water?
A: Pure water has a pH of 7 at 25°C. This can vary slightly with temperature changes.

Q3: How does pH relate to pOH?
A: In aqueous solutions at 25°C, pH + pOH = 14. pOH is calculated similarly using OH- concentration instead of H+.

Q4: What's the range of possible pH values?
A: While the theoretical range is 0-14, some concentrated acids can have negative pH values and some concentrated bases can exceed pH 14.

Q5: Why is logarithmic scale used for pH?
A: The logarithmic scale conveniently represents the wide range of hydrogen ion concentrations found in solutions (from about 1 M to 10^-14 M).