Question

In: Chemistry

column chromatography lab question: what will happen if hexane and dichloromethane are mixed (dichloromethane is run...

column chromatography lab question: what will happen if hexane and dichloromethane are mixed (dichloromethane is run first). how will this be fixed

Solutions

Expert Solution

Solutions:-

When Hexane and dichloromethaneare mixed neither of the two compounds elute off the column, then we can conclude that the solvent is not polar enough to strip the compounds from their affinity to the stationary phase. To fix this, a more polar solvent should be selected for use, but it cannot be too polar otherwise both of the compounds will elute off at the same time.

If the two compounds that you desire to separate elute from the column at the same time, you can conclude that the two halogenated alkenes have too similar of retardation factors for a solvent such as dichloromethane to separate. In order to fix this problem, the student should use two different solvents, starting with a less polar solvent such as petroleum ether and then switch to a more polar solvent such as MtBE. The petroleum ether would elute out the less polar of the two halogenated alkenes while the MtBE would elute out the more polar of the two halogenated alkenes. The use of two different solvents would result in a separation of the two mixed compounds.


Related Solutions

column chromatography lab question: what will happen if hexane and dichloromethane are mixed (dichloromethane is run...
column chromatography lab question: what will happen if hexane and dichloromethane are mixed (dichloromethane is run first). how will this be fixed
During a column chromatography laboratory experiment, a column is to be run with hexane first, then...
During a column chromatography laboratory experiment, a column is to be run with hexane first, then a hexane/ dichloromethane mixture, then 100% dichloromethane. What will happen if you mix up the hexane and dichloromethane? How can you fix the problem?
Column Chromatography Lab 1. What would happen if diethyl ether were put in the column first...
Column Chromatography Lab 1. What would happen if diethyl ether were put in the column first instead of petroleum ether? 2. The recrystallization lab required you to purify naphthalene which contained a small portion of fluorenone. Could you use column chromatography to purify the same mixture? Would the selection of solvents be different from those used in this lab?
Explain what would happen if the hexane was added to the top of the column immediately...
Explain what would happen if the hexane was added to the top of the column immediately after adding the sample. This is for isolation of chlorophyll and carotenoid pigments from spinach
In a Column Chromatography of spinach extract experiment a post lab question is as follows: Compare...
In a Column Chromatography of spinach extract experiment a post lab question is as follows: Compare the order of elution from the column with the Rf of the observed compounds. Is there a correlation? If yes, what is it?
What would happen if you ran a flash (chromatography) column using a solvent where the Rf...
What would happen if you ran a flash (chromatography) column using a solvent where the Rf fo the lower spot was 0.5? What would happen if you ran a flash column where the Rf value of the upper spot was .2 and the Rf value of the lower spot was .05?
In organic chemistry lab chromatography, explain why the fluorence moved through the column in Part C...
In organic chemistry lab chromatography, explain why the fluorence moved through the column in Part C first and fluorenone followed? What would the result of using too much in a too tight plug for Part C? Using a choice of hexane, dichloromethane or actone, indicate which solvent you would use to separate the following pairs of compounds. a. Acetophenone and 2-phenylethanol b. Bromobenzene and p-xylene c. Saliclicacid and o-nitrobenzoic acid
Proof read lab report on theory of column chromatography. We just did TLC last week and...
Proof read lab report on theory of column chromatography. We just did TLC last week and now we are doing column.   Some key points in my background need to include.   Describe Column chromatography and its applications Choosing solvents for column chromatography sample and column size packing column two methods, adding sample, eluting column, and monitoring column Column chromatography is used to purify individual chemical compounds from mixtures. Generally, it is used in a glass tube from 5 mm to 50...
Proof read lab report on theory of column chromatography. We just did TLC last week and...
Proof read lab report on theory of column chromatography. We just did TLC last week and now we are doing column.   Some key points in my background need to include.   Describe Column chromatography and its applications Choosing solvents for column chromatography sample and column size packing column two methods, adding sample, eluting column, and monitoring column Column chromatography is used to purify individual chemical compounds from mixtures. Generally, it is used in a glass tube from 5 mm to 50...
Using Silica or Alumina in packing the column results in “Normal” chromatography. What is reversed-phase chromatography...
Using Silica or Alumina in packing the column results in “Normal” chromatography. What is reversed-phase chromatography and why is it useful?
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT