Questions 1. A sample was placed on a chromatography column. When methylene chlo
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Questions 1. A sample was placed on a chromatography column. When methylene chloride was used as the eluting solvent, all of the components eluted off the column, but there was no separation between them. Why? How would you change this experiment to resolve this problem? 2. Consider a sample that is a mixture composed of benzoic acid, biphenyl, and benzyl alcohol. Predict the order of elution of the components in the mixture. Assume that the chromatography uses a silica column and the solvent is hexane, with an increasing portion of methylene chloride added as a function of time.Explanation / Answer
1. This is because all the components are soluble in methylene chloride and as a result when it is used as the eluent, all the components eluted off. To resolve this issue, the polarity of solvent must be lower i.e. mixture of solvents should be used such as hexane-methylene chloride in order to lower the polarity. In that case, a better separation would be achieved among the components.
2. In the column, biphenyl will come first, followed by benzyl alcohol and then benzoic acid. It is because biphenyl is less polar amongst them followed by benzyl alcohol and then benzoic acid.
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