Spectrophotometric Determination of a Food Dye

Instructions

Part 2 of 2: Molar Absorptivity Coefficient
Use this page to check whether you have carried out the calculation of the molar absorptivity coefficient in the Spectrophotometric Determination of a Food Dye lab correctly. This page does not tell you if your value of the molar absorptivity coefficient is correct; it only tells you whether the value you calculated is consistent with the data you collected. Enter your data as indicated below, paying special attention to the indicated units. Enter values of %T as percents; for example, use 51.3% instead of 0.513. When you have entered all of the data, select "Check Calculation". You will be told how close your calculated value is to the value calculated by the computer.
Mass FD&C red 40 used to prepare stock solution: g %T of standard solution 1: % %T of standard solution 5: % %T of standard solution 10: % %T of standard solution 15: % Your calculated molar absorptivity coefficient: L mol-1 cm-1

University of Oregon, Chemistry Teaching Laboratories
Script written and maintained by: Dr. Christopher Grant [send email]
Last Update: Thursday, 2 October 1997