pH Calculator
Calculate pH, pOH, and ion concentrations of solutions
Calculate pH and pOH
Molar concentration of H⁺ ions in solution
pH Analysis Results
Key relationships: pH = -log₁₀([H⁺]), pOH = -log₁₀([OH⁻])
Water equilibrium: pH + pOH = 14 (at 25°C)
Ion product: [H⁺] × [OH⁻] = 1.0 × 10⁻¹⁴ M²
pH Scale Position
Your solution (pH 0.00) is positioned on the scale above.
Example: Hydrochloric Acid
Given
Solution: 0.001 M HCl
[H⁺]: 0.001 M = 1×10⁻³ M
HCl is strong acid: Complete dissociation
Calculation
pH = -log₁₀([H⁺])
pH = -log₁₀(1×10⁻³)
pH = -(-3) = 3
Result: pH = 3 (Strong Acid)
pH Scale Reference
Very Strong Acid
Battery acid, stomach acid
Weak Acid
Orange juice, coffee
Nearly Neutral
Milk, saliva
Neutral
Pure water
Weak Base
Baking soda, seawater
Strong Base
Bleach, drain cleaner
Key Formulas
pH Formula
pH = -log₁₀([H⁺])
pOH Formula
pOH = -log₁₀([OH⁻])
Water Equilibrium
pH + pOH = 14
Ion Concentrations
[H⁺] = 10⁻ᵖᴴ
[OH⁻] = 10⁻ᵖᴼᴴ
Water Ion Product
[H⁺][OH⁻] = 1×10⁻¹⁴
pH Measurement Tips
Calibrate pH meter regularly
Temperature affects pH readings
Use fresh buffer solutions
Consider ionic strength effects
Understanding pH and Acidity
What is pH?
pH (potential of Hydrogen) is a scale used to measure the acidity or basicity of aqueous solutions. It quantifies the concentration of hydrogen ions [H⁺] in solution. The pH scale typically ranges from 0 to 14, where lower values indicate acidic solutions and higher values indicate basic solutions.
Why is pH Important?
- •Critical for biological processes and enzyme activity
- •Essential for water quality and environmental monitoring
- •Important in food processing and preservation
- •Crucial for chemical reactions and industrial processes
Mathematical Relationships
pH Definition
pH = -log₁₀([H⁺])
Logarithmic scale based on hydrogen ion concentration
Water Equilibrium
pH + pOH = 14
At 25°C in aqueous solutions
Ion Product of Water
[H⁺][OH⁻] = 1×10⁻¹⁴
Constant at 25°C
Note: pH is temperature-dependent. Most pH calculations assume 25°C (298 K). At different temperatures, the ion product of water changes.