Kinetic Molecular Theory, Real Gases & Analytical Calculators

Henderson-Hasselbalch Buffer pH Calculator

Calculate exact buffer pH, pOH, and buffer capacity ratio from weak acid pKa and conjugate base/acid concentrations.

Henderson-Hasselbalch Buffer pH Calculator pH = pKa + log₁₀([A⁻] / [HA])

Calculate exact buffer pH, pOH, and buffer capacity ratio from weak acid pKa and conjugate base/acid concentrations.

Acid pKa

Weak Acid [HA] (M)

Conjugate Base [A⁻] (M)

Molarity & Solution Preparation Calculator M = m / (Mw × V) | m = M × Mw × V

Compute molar concentration (mol/L), required solute mass (g), or solution volume (mL) for laboratory preparation.

Solute Mass (g)

Molar Mass Mw (g/mol)

Solution Volume (mL)

Stock Dilution Calculator (C₁V₁ = C₂V₂) C₁ × V₁ = C₂ × V₂

Determine exact aliquot volume V₁ of concentrated stock solution and solvent volume required to reach target concentration C₂.

Stock Concentration C₁ (M)

Target Concentration C₂ (M)

Final Volume V₂ (mL)

Gibbs Free Energy (ΔG°) & Equilibrium Constant (Keq) ΔG° = ΔH° − T·ΔS° | Keq = exp(−ΔG° / RT)

Evaluate reaction spontaneity, Gibbs free energy ΔG° (kJ/mol), and thermodynamic equilibrium constant Keq at any temperature.

Enthalpy ΔH° (kJ/mol)

Entropy ΔS° (J/mol·K)

Temperature T (K)

Nernst Equation & Galvanic Cell EMF Calculator Ecell = E°cell − (RT / nF) · ln(Q)

Compute non-standard galvanic cell potential Ecell (V) and electrical work ΔG from standard potential E°cell, electron transfer n, and reaction quotient Q.

Standard Cell Potential E° (V)

Electrons Transferred (n)

Reaction Quotient (Q)

Temperature T (K)

Beer-Lambert Law & UV-Vis Absorbance Calculator A = ε · ℓ · c | %T = 10^(2 − A)

Relate optical absorbance (A), percent transmittance (%T), molar absorptivity ε, cuvette path length ℓ, and concentration c.

Molar Absorptivity ε (L·mol⁻¹·cm⁻¹)

Cuvette Path Length ℓ (cm)

Concentration (µM)

Arrhenius Activation Energy & Rate Multiplier ln(k₂ / k₁) = (Ea / R) · (1/T₁ − 1/T₂)

Compute how temperature accelerates reaction rate constant k₂/k₁ given activation energy Ea (kJ/mol).

Activation Energy Ea (kJ/mol)

Initial Temp T₁ (K)

Final Temp T₂ (K)

First-Order Kinetics & Isotope Half-Life Calculator N(t) = N₀ · (1/2)^(t / t½) | k = ln(2) / t½

Calculate remaining mass/activity N(t), decay constant k, and mean lifetime τ for first-order reactions and radioisotopes.

Initial Amount N₀ (g or mM)

Half-Life t½ (s, min, or yr)

Elapsed Time t (same unit)

Kinetic Gas Piston Chamber & Maxwell–Boltzmann Speed Curve (P + an²/V²)(V − nb) = nRT

Gas Species (Molar Mass & VdW a, b)

Amount (n): 1.00 mol

Piston Volume (V): 22.4 L

Temperature (T): 298 K

Empirical & Molecular Formula Solver (Combustion / Mass %)

Carbon C (% or g)

Hydrogen H (% or g)

Oxygen O (% or g)

Nitrogen N (% or g)

Target Molar Mass (g/mol)