Question

Percent by mass of dye in Fruit Loops cereal 11.56*100 QUESTIONS: 1. If the molar extinction coefficient (E) of a compound is 2.5 x 108 moli'cmat $28 nm and the Abs Cat 528 nm) 0.254 Dind the concentration of that solution. (assume a path length of 1.0 cm) 2. If a student measures a sample that gives an Abs = 1.85 at the 2max, is this data reliable? If not, then what might they do to improve their data? 3. If your stock solution has a concentration of 0.75 M and you want to make 250 mL of a solutie that has a concentration of 4.8 x 10-M, how much stock solution will you need? 102

Answer 1

1. According to Lambert-Beer's law – A = e.el A = Absorbance = 0.254 E = Molar estinetion coefficien or 0:254 = 2.5*10* C * 1 = 2:5 *105 mot-cu? or e = 10.254 L = path length =1 cm - 2158105 ca Molas concentration of Solution = 1:016 xlö ©CM)