Homework Help is Here – Start Your Trial Now!
Science
Chemistry
1. a) How would you expect the melting point of the product of the acidic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer. b) How would you expect the melting point of the product of the basic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer.

1. a) How would you expect the melting point of the product of the acidic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer. b) How would you expect the melting point of the product of the basic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer.

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
icon
Concept explainers
Question
REACTION Acidic conditions REACTION Basic conditions In a round-bottom flask of appropriate size attached over a stirring plate, stir 4-methoxyacetophenone (6.00 mmol) and acetic acid ([ketone] = 0.90 M) until homogeneous. Add bleach (6% m/v NaOCI, 1.60 eq.) slowly, over a few minutes. Allow the mixture to stir at room temperature for 20 minutes, then monitor the reaction by TLC. If starting material can still be found, add a slight excess of bleach (0.10 eq.), stir an additional 10 minutes and check again by TLC. In a round-bottom flask of appropriate size, add sequentially 4-methoxyace- tophenone (3.50 mmol), bleach (6% m/v NaOCI; 6.00 eq) and 3M NAOH (1.00 eq.). Asemble a reflux apparatus, and boil the resulting mixture for approximately 20 minutes. Analyze the reaction by TLC: if the reaction is still ongoing, reflux an additonal 5 minutes before repeating this TLC step. Once over, add ~2 mL of acetone to the mixture through the condenser. Allow the solution to gently boil for another 10 minutes. PURIFICATION Once the reaction is judged complete by TLC, add 20 mL of water. Allow to stir for approximately 5 minutes, then filter the solid using vacuum-filtration, rinsing it abundantly with water. Manually pump it dry for a few minutes be- fore weighing it to get a crude mass. Cool the warm reaction mixture in an ice-bath for 10 minutes. Transfer the solution to a separatory funnel and wash the aqueous solution with ethyl acetate (2x10 mL). Transfer the aqueous solution to an ice bath: using con- centrated hydrochloric acid, carefully acidify the mixture to a pH of ~1 to obtain a precipitate. Keep the mixture in the ice bath for an additional 10 minutes to complete the precipitation. PURIFICATION Transfer most of your crude solid (keep some aside in case of an emer- gency) to a 125 mL erlenemeyer, and recrystallize it using a minimal vol- ume of a boiling 1:1 mixture of methanol and water. Allow to cool to room temperature for a few minutes, then transfer into an ice-bath to terminate crystallization. Allow to sit in ice for -10 min. Isolate the solid using vacuum- filtration; rinse it with cold water, and dry it using a water aspirator for ~10 minutes. Weigh the solid, then proceed to analyze it using both TLC and melting point analysis. Vacuum-filter this solid: wash it thoroughly with cold water, then dry it as much as possible using a water aspirator. Weigh the solid, and analyze it using TLC and a melting point analysis. TIPS Make sure you allow the reaction to cool for a minute or two before opening the condenser for TLC to avoid burning yourself on hot vapours. Don't skip the addition of acetone! Your lungs will thank you later... The product precipitates in acidic conditions: if a solid forms and redis- solves, your solution is not sufficiently acidic yet. TIPS In case of an issue with the recrystallization, you can try and analyze the crude solid that you have put aside to have some preliminary data. Due to the high demand for vacuum-filtrations, use a single filtration- flask in your setup rather instead of two.
Transcribed Image Text:REACTION Acidic conditions REACTION Basic conditions In a round-bottom flask of appropriate size attached over a stirring plate, stir 4-methoxyacetophenone (6.00 mmol) and acetic acid ([ketone] = 0.90 M) until homogeneous. Add bleach (6% m/v NaOCI, 1.60 eq.) slowly, over a few minutes. Allow the mixture to stir at room temperature for 20 minutes, then monitor the reaction by TLC. If starting material can still be found, add a slight excess of bleach (0.10 eq.), stir an additional 10 minutes and check again by TLC. In a round-bottom flask of appropriate size, add sequentially 4-methoxyace- tophenone (3.50 mmol), bleach (6% m/v NaOCI; 6.00 eq) and 3M NAOH (1.00 eq.). Asemble a reflux apparatus, and boil the resulting mixture for approximately 20 minutes. Analyze the reaction by TLC: if the reaction is still ongoing, reflux an additonal 5 minutes before repeating this TLC step. Once over, add ~2 mL of acetone to the mixture through the condenser. Allow the solution to gently boil for another 10 minutes. PURIFICATION Once the reaction is judged complete by TLC, add 20 mL of water. Allow to stir for approximately 5 minutes, then filter the solid using vacuum-filtration, rinsing it abundantly with water. Manually pump it dry for a few minutes be- fore weighing it to get a crude mass. Cool the warm reaction mixture in an ice-bath for 10 minutes. Transfer the solution to a separatory funnel and wash the aqueous solution with ethyl acetate (2x10 mL). Transfer the aqueous solution to an ice bath: using con- centrated hydrochloric acid, carefully acidify the mixture to a pH of ~1 to obtain a precipitate. Keep the mixture in the ice bath for an additional 10 minutes to complete the precipitation. PURIFICATION Transfer most of your crude solid (keep some aside in case of an emer- gency) to a 125 mL erlenemeyer, and recrystallize it using a minimal vol- ume of a boiling 1:1 mixture of methanol and water. Allow to cool to room temperature for a few minutes, then transfer into an ice-bath to terminate crystallization. Allow to sit in ice for -10 min. Isolate the solid using vacuum- filtration; rinse it with cold water, and dry it using a water aspirator for ~10 minutes. Weigh the solid, then proceed to analyze it using both TLC and melting point analysis. Vacuum-filter this solid: wash it thoroughly with cold water, then dry it as much as possible using a water aspirator. Weigh the solid, and analyze it using TLC and a melting point analysis. TIPS Make sure you allow the reaction to cool for a minute or two before opening the condenser for TLC to avoid burning yourself on hot vapours. Don't skip the addition of acetone! Your lungs will thank you later... The product precipitates in acidic conditions: if a solid forms and redis- solves, your solution is not sufficiently acidic yet. TIPS In case of an issue with the recrystallization, you can try and analyze the crude solid that you have put aside to have some preliminary data. Due to the high demand for vacuum-filtrations, use a single filtration- flask in your setup rather instead of two.
1. a) How would you expect the melting point of the product of the acidic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer. b) How would you expect the melting point of the product of the basic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer.
Transcribed Image Text:1. a) How would you expect the melting point of the product of the acidic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer. b) How would you expect the melting point of the product of the basic reaction to behave as compared to the starting 4-methoxyacetophenone (i.e. higher, similar, lower)? Explain your answer.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Ethers
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.
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