Question

Plot the following data as absorbance versus[XX] as a calibration curve:
Absorbance  
0.0453
0.097
0.14
0.35
0.51

Standard Concentration of XX
3.0 *10^-4 mol/L
6.2*10^-4 mol/L
9.0*10^-4 mol/L
2.2*10^-3 mol/L
3.2*10^-3 mol/L

A “test" solution showed a percent transmittance(%T) reading 38.4%T.Interpret the calibration curve to determine the molar concentration of XX in the test solution.

Answer 1

Ans. Absorbance of the unknow = 2 – log (%T) = 2 – log 38.4 = 0.4157

# Hence, unknown [XX] = 2.61 x 10^-3 M