Chapter4: Least-squares And Calibration Methods
Section: Chapter Questions
Problem 3P
Related questions
Question
![Column Chromatography of 9-Fluorenone Experiment
Introduction:
Column chromatography is an important chromatography method used to separate and purify
organic compounds. Column chromatography is typically used to separate impurities and purify
products from chemical reactions, including separating unused starting material from products.
Column chromatography is very similar to Thin Layer Chromatography (TLC) because it relies on a
solid stationary phase (absorbent) and liquid mobile phase (eluant) to separate organic compounds
based on their different polarities.
In column chromatography, the stationary phase is a solid
absorbent, typically silica gel or alumina, with a liquid coating
packed into a glass column. The stationary phase is typically very
polar. An eluant (mobile phase) solvent travels down the column
and the separation occurs as the organic compounds enter into
equilibria with the stationary and mobile phases. The polarity of the
eluant may be adjusted from non-polar solvents, such as hexanes or
petroleum ether, to very polar dichloromethane or ethyl acetate;
mixtures of hexanes and ethyl acetate are typically used to finely
tune the polarity of the eluant as needed for each separation.
-Solvent: Entire column must always
be under solvent
-Sand (1 cm)
Alumina: 25 g for every 1g
of mixture to
be separated
-Sand (1 em)
Glass wool or cotton
Stopcock to control flow
As in TLC, non-polar compounds are not attracted to the polar
stationary phase and travel easily down a column with a non-polar
eluant. By contrast, polar compounds are attracted to the polar
stationary phase and will require an eluant with more polarity to
travel down the column. As the organic compounds elute from the
column, they are collected in flasks or test tubes as dissolved material in the eluant, this is called a
fraction. It is recommended to always test each fraction by TLC to confirm the identity of the
organic compound and ensure that no other compounds are in that fraction.
Collection flask
Once a compound has been eluted from the column, simple evaporation of the eluant allows for the
recovery of the purified organic compound.
Add alumina
Add Eluent Add Eluent
Add Eluent
Add Eluent
Add compound
Then "pack;
Collect
Collect
compound I compound 2](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2512f82d-69c0-4421-95ac-43df259f3b1a%2F594e9546-a398-4bb5-98d3-2606745d589b%2F2en1bdo_processed.jpeg&w=3840&q=75)
Transcribed Image Text:Column Chromatography of 9-Fluorenone Experiment
Introduction:
Column chromatography is an important chromatography method used to separate and purify
organic compounds. Column chromatography is typically used to separate impurities and purify
products from chemical reactions, including separating unused starting material from products.
Column chromatography is very similar to Thin Layer Chromatography (TLC) because it relies on a
solid stationary phase (absorbent) and liquid mobile phase (eluant) to separate organic compounds
based on their different polarities.
In column chromatography, the stationary phase is a solid
absorbent, typically silica gel or alumina, with a liquid coating
packed into a glass column. The stationary phase is typically very
polar. An eluant (mobile phase) solvent travels down the column
and the separation occurs as the organic compounds enter into
equilibria with the stationary and mobile phases. The polarity of the
eluant may be adjusted from non-polar solvents, such as hexanes or
petroleum ether, to very polar dichloromethane or ethyl acetate;
mixtures of hexanes and ethyl acetate are typically used to finely
tune the polarity of the eluant as needed for each separation.
-Solvent: Entire column must always
be under solvent
-Sand (1 cm)
Alumina: 25 g for every 1g
of mixture to
be separated
-Sand (1 em)
Glass wool or cotton
Stopcock to control flow
As in TLC, non-polar compounds are not attracted to the polar
stationary phase and travel easily down a column with a non-polar
eluant. By contrast, polar compounds are attracted to the polar
stationary phase and will require an eluant with more polarity to
travel down the column. As the organic compounds elute from the
column, they are collected in flasks or test tubes as dissolved material in the eluant, this is called a
fraction. It is recommended to always test each fraction by TLC to confirm the identity of the
organic compound and ensure that no other compounds are in that fraction.
Collection flask
Once a compound has been eluted from the column, simple evaporation of the eluant allows for the
recovery of the purified organic compound.
Add alumina
Add Eluent Add Eluent
Add Eluent
Add Eluent
Add compound
Then "pack;
Collect
Collect
compound I compound 2
![In this experiment, the eluant is?
1)
petroleum ether
O 2) water
3) dichloromethane
4) ethyl acetate](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F2512f82d-69c0-4421-95ac-43df259f3b1a%2F594e9546-a398-4bb5-98d3-2606745d589b%2F4685ww_processed.jpeg&w=3840&q=75)
Transcribed Image Text:In this experiment, the eluant is?
1)
petroleum ether
O 2) water
3) dichloromethane
4) ethyl acetate
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Knowledge Booster
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
![Macroscale and Microscale Organic Experiments](https://www.bartleby.com/isbn_cover_images/9781305577190/9781305577190_smallCoverImage.gif)
Macroscale and Microscale Organic Experiments
Chemistry
ISBN:
9781305577190
Author:
Kenneth L. Williamson, Katherine M. Masters
Publisher:
Brooks Cole
![Macroscale and Microscale Organic Experiments](https://www.bartleby.com/isbn_cover_images/9781305577190/9781305577190_smallCoverImage.gif)
Macroscale and Microscale Organic Experiments
Chemistry
ISBN:
9781305577190
Author:
Kenneth L. Williamson, Katherine M. Masters
Publisher:
Brooks Cole
![EBK A SMALL SCALE APPROACH TO ORGANIC L](https://www.bartleby.com/isbn_cover_images/9781305446021/9781305446021_smallCoverImage.jpg)
EBK A SMALL SCALE APPROACH TO ORGANIC L
Chemistry
ISBN:
9781305446021
Author:
Lampman
Publisher:
CENGAGE LEARNING - CONSIGNMENT
![Principles of Instrumental Analysis](https://www.bartleby.com/isbn_cover_images/9781305577213/9781305577213_smallCoverImage.gif)
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
![Chemical Principles in the Laboratory](https://www.bartleby.com/isbn_cover_images/9781305264434/9781305264434_smallCoverImage.gif)
Chemical Principles in the Laboratory
Chemistry
ISBN:
9781305264434
Author:
Emil Slowinski, Wayne C. Wolsey, Robert Rossi
Publisher:
Brooks Cole