Assess students' ability to apply the Beer–Lambert law (A = ε·l·c) to determine solute concentration from UV–Vis absorbance data. Tasks include using provided molar absorptivity (ε) and cuvette path length (l) to calculate concentration, applying dilution factors and unit conversions, constructing or using a linear calibration curve from standards, checking that absorbance lies within the instrument's linear range, and reporting the final concentration with correct units and significant figures. Simple numerical calculations and a brief validity check are expected.