Colorimetry
Determine the concentration of a colored substance using absorbance measurements
Step 1: Prepare Standards (Serial Dilution)
CuSO₄
Stock Solution
0.10 M
1
2
3
4
5
Cuvettes 1–5 correspond to 0.02, 0.04, 0.06, 0.08, and 0.10 mol dm⁻³.
Calibration Curve
Absorbance vs. concentration (A = 15 × c)
Beer-Lambert Law
- 0.02 M → A = 0.30; 0.10 M → A = 1.50
- After all 5 standards are measured, the line of best fit passes through the origin.