Texts:
1- Calculate the molar absorptivity (ε) of compound X if the absorbance was measured to be 0.695 and the concentration was 0.0342 mol/L, and the cell has a 2.60 cm path length. Report your answer to 2 decimal places.
2- The absorbance was measured as a function of the concentration of a colored complex. The equation of the calibration curve was reported to be A = 0.036c, where A is the absorbance and c is the concentration in ppm. If the molar mass of the colored complex is 198.69 g/mol, and the cell path length is 1.00 cm, calculate the molar absorptivity (ε). Report your answer to the nearest whole number.
3- Calculate the concentration of an unknown tartrazine sample by standard addition, given the following experiment:
Step 1: A 2.00 mL aliquot of an unknown tartrazine sample was diluted to 100.0 mL, and the absorbance measured to be 0.353.
Step 2: A 2.00 mL aliquot of an unknown tartrazine sample was placed in a 100.0 mL flask. A 2.00 mL aliquot of a 100.00 ppm tartrazine standard was added to the flask, and the absorbance measured to be 0.590. Report your answer to 1 decimal place, the nearest whole number, without units.
Hint: Remember the dilution factor.