pH Calculator

Solution Type: Strong Acid

Concentration: 0.1 M

pH: 1.00

[H⁺]: 1.00e-1 M

pH Scale & Indicator Colors

Acidic (0-6)

Neutral (7)

Basic (8-14)

Titration Curve

Volume Added: 0.00 mL

Current pH: 1.00

pH vs [H⁺] (Logarithmic)

pH = -log[H⁺]

Solution Parameters & Controls

Solution Type

Solution Type:

Concentration

Concentration: 0.1 M

Value is log₁₀(c), range: 10⁻⁷ to 10¹ M

Weak Acid/Base Constants

Ka (Acid) / Kb (Base): 1.80e-5

Value is log₁₀(Ka), range: 10⁻¹⁰ to 10⁻²

Titration Simulation

Titrant Concentration: 0.1 M Volume of Titrant Added: 0.00 mL

Quick Presets

Compare Solutions

Show Comparison:

pH Calculation Formulas

pH Definition: pH = -log[H⁺]

Strong Acid: pH = -log(c)

Strong Base: pOH = -log(c), pH = 14 - pOH

Weak Acid: [H⁺] = √(Ka·c), pH = -log[H⁺]

Weak Base: [OH⁻] = √(Kb·c), pOH = -log[OH⁻]

Water Autoionization: Kw = [H⁺][OH⁻] = 10⁻¹⁴ (25°C)

What is pH?

pH is a measure of the acidity or basicity of a solution, defined as the negative logarithm (base 10) of the hydrogen ion concentration: pH = -log[H⁺]. The scale typically ranges from 0 to 14, where pH < 7 indicates acidity, pH > 7 indicates basicity (alkalinity), and pH = 7 is neutral at 25°C.

Strong Acids and Bases

Strong acids completely dissociate in water. Strong bases completely dissociate to produce OH⁻ ions. Used in batteries, cleaning products, and industrial processes.

Weak Acids and Bases

Weak acids partially dissociate, establishing equilibrium. Weak bases partially accept protons. Common in vinegar, soda, and cleaning products.

Acid-Base Titration

Titration involves gradual addition of a titrant to study pH changes. The curve reveals buffer regions and equivalence points.

Logarithmic Nature of pH

Each pH unit represents a 10-fold change in [H⁺]. Biological systems require tight pH control for proper enzyme function.

Polyprotic Acids

Acids with multiple dissociable protons, each with its own dissociation constant. Examples include sulfuric and phosphoric acid.

Real-World Applications

Environmental monitoring, medical diagnostics, food industry, industrial processes, and agriculture.