Langmuir Isotherm Calculator

mg/L
mg/g
L/mg
Chemistry

Calculate the amount adsorbed on a surface at a given concentration using the Langmuir adsorption isotherm.

Formula

qe = (Qmax × KL × Ce) / (1 + KL × Ce); RL = 1 / (1 + KL × C₀)
  • qe = equilibrium adsorption capacity (mg/g).
  • Separation factor RL: 0 < RL < 1 = favorable; RL = 0 = irreversible; RL = 1 = linear; RL > 1 = unfavorable.
  • Langmuir assumes monolayer adsorption on homogeneous surface.

Ce=10 mg/L, Qmax=100 mg/g, KL=0.1 L/mg

Inputs
  • Equilibrium Concentration (Ce): 10 mg/L
  • Maximum Adsorption Capacity (Qmax): 100 mg/g
  • Langmuir Constant (KL): 0.1 L/mg

qe = (100 × 0.1 × 10) / (1 + 0.1 × 10) = 100/2 = 50 mg/g.

Frequently asked questions

What does the Langmuir model assume?
Monolayer adsorption on a surface with a finite number of identical, equally accessible sites.
What is a separation factor?
RL indicates the favorability of the isotherm. RL between 0 and 1 indicates favorable adsorption.