Homework Help is Here – Start Your Trial Now!
Science
Chemistry
i need to caluclate a rf value for the tlc plate and i really need help with showing the steps please!   Reduction of 4-Nitrobenzaldehyde to 4-Nitrobenzyl Alcohol and Thin Layer Chromatography

i need to caluclate a rf value for the tlc plate and i really need help with showing the steps please!   Reduction of 4-Nitrobenzaldehyde to 4-Nitrobenzyl Alcohol and Thin Layer Chromatography

Chemistry
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...
See similar textbooks
icon
Related questions
Question

i need to caluclate a rf value for the tlc plate and i really need help with showing the steps please!

 

Reduction of 4-Nitrobenzaldehyde to 4-Nitrobenzyl Alcohol and Thin Layer Chromatography

A = 4-nitrobenzaldehyde (starting material) B = both C = 4-nitrobenzyl alcohol (product) A B.
Transcribed Image Text:A = 4-nitrobenzaldehyde (starting material) B = both C = 4-nitrobenzyl alcohol (product) A B.
After the reaction has been completed, add about 20 mL of methylene chloride (dichloromethane/ DCM), and pour the solution into a separatory funnel. Add 20 mL of water to the separatory funnel. Shake and let the aqueous and organic layers separate. Place the organic layer (which layer is that?) with your product in an Erlenmeyer flask. Repeat with another portion of methylene chloride. Combine the organic layers and add a drying agent. Gravity filter the solution into 100 mL pre-weighed round-bottom flask and wash the flask and drying agent with an additional 5mL of methylene chloride, also filtered into your round bottom flask. Evaporate the solvent on a steam bath in the hood (Erlenmeyer), or use the rotary evaporator (round bottom flask). Weigh the flask again and calculate the crude yield. (Be sure all solvent has been removed!) Purification by recrystallization. Take a melting point of your crude product. Read the section on recrystallization in your lab text before you come to class. Recrystallization is a technique for purification of a solid compound. In general, the compound (and any impurities) is dissolved in a minimal volume of hot solvent (or solvent mixture). This hot solution is left to cool slowly to room temperature, and then placed in an ice bath. The solubility of compounds is less in colder solutions, so crystals of compound should form slowly from the saturated solution. (Since the impurity should be present in small quantities, the impurity will stay in solution while the compound of interest is crystallizing). If crystal formation is slow enough, the crystal should be pure compound. The purified compound is physically separated from solution by filtration. However, if this crystal formation is fast, impurities may be trapped in the rapidly forming lattice of the solid crystal. Therefore, it is important to be patient while performing a recrystallization. It may help you to see pictures of a movie of the process. Recrystallize the product from methylene chloride, and determine the weight percentage recovery for this purification step once this purified solid has completely dried. If your TLC of CP1 or CP2 contained multiple spots, take a TLC of the purified compound by dissolving a few crystals in methylene chloride and eluting with the same solvent as above (30% ethyl acetate; 70% petroleum ether). Mark this purified product PP.
Transcribed Image Text:After the reaction has been completed, add about 20 mL of methylene chloride (dichloromethane/ DCM), and pour the solution into a separatory funnel. Add 20 mL of water to the separatory funnel. Shake and let the aqueous and organic layers separate. Place the organic layer (which layer is that?) with your product in an Erlenmeyer flask. Repeat with another portion of methylene chloride. Combine the organic layers and add a drying agent. Gravity filter the solution into 100 mL pre-weighed round-bottom flask and wash the flask and drying agent with an additional 5mL of methylene chloride, also filtered into your round bottom flask. Evaporate the solvent on a steam bath in the hood (Erlenmeyer), or use the rotary evaporator (round bottom flask). Weigh the flask again and calculate the crude yield. (Be sure all solvent has been removed!) Purification by recrystallization. Take a melting point of your crude product. Read the section on recrystallization in your lab text before you come to class. Recrystallization is a technique for purification of a solid compound. In general, the compound (and any impurities) is dissolved in a minimal volume of hot solvent (or solvent mixture). This hot solution is left to cool slowly to room temperature, and then placed in an ice bath. The solubility of compounds is less in colder solutions, so crystals of compound should form slowly from the saturated solution. (Since the impurity should be present in small quantities, the impurity will stay in solution while the compound of interest is crystallizing). If crystal formation is slow enough, the crystal should be pure compound. The purified compound is physically separated from solution by filtration. However, if this crystal formation is fast, impurities may be trapped in the rapidly forming lattice of the solid crystal. Therefore, it is important to be patient while performing a recrystallization. It may help you to see pictures of a movie of the process. Recrystallize the product from methylene chloride, and determine the weight percentage recovery for this purification step once this purified solid has completely dried. If your TLC of CP1 or CP2 contained multiple spots, take a TLC of the purified compound by dissolving a few crystals in methylene chloride and eluting with the same solvent as above (30% ethyl acetate; 70% petroleum ether). Mark this purified product PP.
Expert Solution
steps

Step by step

Solved in 3 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Analytical Separations
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
  • SEE MORE 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
SEE MORE TEXTBOOKS