All Science Calculators

30 free calculators for diffusion, chemistry and physics. Type to filter.

Diffusion

Fick's First Law Calculator

Diffusion flux from a concentration gradient

J = −D · dC/dx

Fick's Second Law Calculator

Concentration vs. depth and time (erf solution)

C(x,t) = C₀ + (Cₛ − C₀)·erfc(x/2√Dt)

Diffusion Coefficient vs Temperature (Arrhenius)

D = D₀·exp(−Q/RT) for solids

D = D₀ · exp(−Q/RT)

Stokes–Einstein Equation Calculator

Diffusion coefficient of a particle in a fluid

D = k_B·T / (6π·η·r)

Diffusion Length & Time Calculator

Mean displacement L = √(2nDt)

Graham's Law of Effusion Calculator

Relative effusion/diffusion rates of gases

r₁/r₂ = √(M₂/M₁)

Membrane Diffusion & Permeability Calculator

Flux through a membrane with partition coefficient

J = D·K·ΔC / L

Einstein Relation Calculator (Mobility ↔ Diffusivity)

D = μ·k_B·T / q for charge carriers and ions

D = μ·k_B·T / q

Thermal Diffusivity Calculator

α = k / (ρ·cₚ) — how fast heat diffuses

α = k / (ρ·cₚ)

Chemistry

Ideal Gas Law Calculator

PV = nRT

Combined Gas Law Calculator

P₁V₁/T₁ = P₂V₂/T₂ (Boyle's, Charles's & Gay-Lussac's laws)

P₁V₁/T₁ = P₂V₂/T₂

Molarity Calculator

Concentration from mass, molar mass and volume

Dilution Calculator (C₁V₁ = C₂V₂)

Stock solution dilution

C₁V₁ = C₂V₂

pH Calculator

pH, pOH, [H⁺] and [OH⁻] at 25 °C

pH = −log₁₀[H⁺]

Half-Life & Radioactive Decay Calculator

N = N₀·(½)^(t/t½)

N = N₀·(½)^(t/t½)

Arrhenius Equation Calculator

Reaction rate constant vs temperature

k = A·exp(−Eₐ/RT)

Nernst Equation Calculator

Cell potential under non-standard conditions

E = E° − (RT/nF)·ln Q

Osmotic Pressure Calculator (van 't Hoff)

π = iMRT

π = i·M·R·T

Beer–Lambert Law Calculator

Absorbance A = ε·l·c

Henry's Law Calculator

Gas solubility C = k_H·P

Physics

Ohm's Law Calculator

V = I·R and electrical power

Newton's Second Law Calculator

F = m·a

Kinetic Energy Calculator

KE = ½·m·v²

Gravitational Potential Energy Calculator

PE = m·g·h

Hooke's Law Calculator

Spring force F = k·x

Coulomb's Law Calculator

Electrostatic force between two charges

F = k_e · q₁q₂ / r²

Newton's Law of Universal Gravitation Calculator

F = G·m₁·m₂ / r²

F = G · m₁m₂ / r²

Fourier's Law of Heat Conduction Calculator

Heat transfer rate through a wall

Q̇ = k·A·ΔT / L

Density Calculator

ρ = m / V

Pressure Calculator

P = F / A