Question

ILI Up 2017 Midterm Exam TWO 5. (10 pts) 10.00 mL of a concentrated dye solution is diluted to 750. spectroscopic measurement of the diluted solution rives a percent transmittance, 22.5% for measurements in a cuvet having a pathlength of 2.50 cm and a molar absorptivity of 1050 (L/mol cm)). What is the concentration of the original (undiluted solution

Answer 1

% T = 22:57 .: Absorbance of the diluted solution =%2– log 22,50 = 0.6478 According to Lambert - Beer's Law, A = e.cl A = Absorbance = 0.6478 € = Absorptivity = 1050 Lmcu con.cz_A -10.6478_1 | 1 = 2:50. cui €!! YoSox 2157.' Ċ = Molar tus of the solution = 2.4678x10(M) - The moorility of diluted sohn is 2:4678x104cm) Now, Vundeleted * Mendiluted = Voiluted x Mdiluted 10 ml x Mendiluted = 750 ml x 2.4678710 (M) or Mundiluted = (750 x 2.4678x100) = 0.0185 (M) . The concentration of indelueted Coriginal) solution e's 0.0185(M) 4 10