Question

• Multiple trials are a standard for any experiment. Variations in the data collected during each trial are reported by the use of statistics. Below is a set of data collected for the calibration of a spectrometric experiment that relates the concentration of a solution to the absorbance. The relationship is given by the Beers-Lambert Law,

  A = εbc,

  where A is the absorbance, ε is the molar absorptivity, b is the path length of the spectrometer and c is the solution concentration.

  Table: Absorbance versus Concentration Calibration Data

  Concentration (M)	Trial 1 Absorbance	Trial 2 Absorbance	Trial 3 Absorbance
  0.0	0.148	0.143	0.150
  0.1	0.216	0.226	0.211
  0.2	0.294	0.274	0.297
  0.3	0.363	0.341	0.356
  0.4	0.421	0.443	0.434
  0.5	0.511	0.481	0.516
  0.6	0.577	0.554	0.560
  0.7	0.629	0.623	0.629
  0.8	0.706	0.706	0.720
  0.9	0.799	0.768	0.807
  1.0	0.846	0.811	0.846
  1.1	0.934	0.953	0.897
  1.2	1.016	0.966	0.966

• Question

  What is the molar absorptivity for your substance if the path length of your spectrometer is 1.3 cm? (Enter your answer to two significant figures.)

Answer 1