Polytechnic Round 1/6 Score 0/600

Colour and Concentration

Beer–Lambert spectroscopy laboratory

Cuvette challenge

Prepare the sample

SOURCE I₀ CUVETTE l = 1 cm I DETECTOR Solution concentration
Predicted absorbance 0.000
Predicted transmittance 100%

Concept: More absorbing molecules along the light path mean less transmitted light.

The maths
A = εcl
T = 10−A
%T = 100T
A = 2 − log₁₀(%T)
c = A/(εl)

ε: L/(mol·cm); c: mol/L; l: cm; A: dimensionless; %T: percent.

Assumption: homogeneous, non-scattering solution at one wavelength, in the linear Beer–Lambert regime.

Live quantitative plots

Calibration and transmission

Model curve Current sample ●
Experiment controls

Set the concentration