Caffeine, C8H10O2N4 H2O (MW = 212.2 g/mol) has been shown to have an average absorbance of 0.644 for a concentration of 1.783 mg per 100 mL at 272 nm. A sample of 3.658 g of a soluble coffee product was mixed with water to a volume of 500 mL and a 25 mL aliquot was transferred to a flask containing 25 mL of 0.1 M H2SO4. This was subjected to the prescribed clarification treatment and made up to 500 mL. A portion of this treated solution showed an absorbance of 0.666 at 272 nm. Assumbe b = 1.0 cm.   Calculate the % caffeine (w/w) in the sample.

Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
icon
Related questions
Question

Caffeine, C8H10O2N4 H2O (MW = 212.2 g/mol) has been shown to have an average absorbance of 0.644 for a concentration of 1.783 mg per 100 mL at 272 nm. A sample of 3.658 g of a soluble coffee product was mixed with water to a volume of 500 mL and a 25 mL aliquot was transferred to a flask containing 25 mL of 0.1 M H2SO4. This was subjected to the prescribed clarification treatment and made up to 500 mL. A portion of this treated solution showed an absorbance of 0.666 at 272 nm. Assumbe b = 1.0 cm.

 

Calculate the % caffeine (w/w) in the sample. 

Expert Solution
steps

Step by step

Solved in 7 steps with 6 images

Blurred answer
Knowledge Booster
Quality Assurance and Calibration Methods
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY