Question

In: Chemistry

Nucleophilic Substitution Reactions Organic Chemistry Lab: Explain the order of elution you observed while performing the...

Nucleophilic Substitution Reactions Organic Chemistry Lab:

Explain the order of elution you observed while performing the gas chromatography for this experiment. What property of the product molecules seem to be the most important in determining relative retention times?

Solutions

Expert Solution

In gas GC, the stationary phase is a high boiling point liquid and mobile phase is an inert gas.The retention times is generally measured as the time taken by the analyte liquid mixture (volatilized in the hot chamber where it is injected in minute quantity), to travel from injection junction to the detector. The detector measures this time interval in minutes.

For efficient separation of components of mixture , the rate of travelling through the column is important. This rate depends on several factors=

But in nucleophillic substitution reactions the ,polarity of the products is an important factor that effects the RRT(relative retention time) : Polar compounds move slowly in polar columns.

The products if are alkyl halides then the order of polarity would be –RF>RCl>RBr>RI

So the more polar one will be retained longer, and have Higher RRT.

RRT=tr/tm

Where, tr= retention time of analyte

tm=retention time for standard species

elution order= RF<RCl<RBr<RI

Other factors that influence the RT are

Boiling point difference of compounds in the mixture is the most important factor, the higher the difference the higher will be the relative retention time of the compound.

    Volatility of product : More volatile component travels faster through the column

    Column specific temperature: Raising the temperature speeds up the rate of all components of the mixture.

    Length of column: longer column, the longer will be the retention time,

However the relative retention time does not change.


Related Solutions

provide background on nucleophilic substitution reactions in general and ambidentate nucleophiles specifically including a definition of...
provide background on nucleophilic substitution reactions in general and ambidentate nucleophiles specifically including a definition of the term and what factors are important in determining the product distribution. It would be helpful to include structures to reinforce your statements
Propose a nucleophilic aromatic substitution mechanisms for the reactions of a) 2,4-dinitrochlorobenzene + sodium methoxide b)...
Propose a nucleophilic aromatic substitution mechanisms for the reactions of a) 2,4-dinitrochlorobenzene + sodium methoxide b) 2,4-dimethylchlorobenzene + sodium hydroxide, 350 degrees C c) p-nitrobromobenzene + methylamine d) 2,4-dinitrochlorobenzene
23. KCN is insoluble in benzene but in the presence of 18-crown-6 the nucleophilic substitution reactions...
23. KCN is insoluble in benzene but in the presence of 18-crown-6 the nucleophilic substitution reactions take place very fast using CNas nucleophile- Justify with mechanism. 24. Arylamines and heterocyclic aromatic amines are considerably less basic than alkylamines — Justify. 25. p-Anisidine is more basic than aniline — Justify with appropriate drawings.
This is Organic Chemistry Lab, Solvent Extraction. 1. What are the criteria for solubility of organic...
This is Organic Chemistry Lab, Solvent Extraction. 1. What are the criteria for solubility of organic molecules in water? 2. If methylene chloride was used as the organic solvent in solvent extraction, instead of ether, what would the top layer be in the separation step? 3. What formula was used to calculate interaction of organic compounds with the stationary phase? 4. In the given mixture (liquid-liquid), which compound (be specific) has the weakest interaction with the stationary phase? Why?
Which one of the following statements does not correctly describe unimolecular nucleophilic substitution (SN1) reactions of...
Which one of the following statements does not correctly describe unimolecular nucleophilic substitution (SN1) reactions of alkyl halides? (">" means "reacts faster than") A) Carbocations are intermediates in unimolecular nucleophilic substitutions. B) The order of decreasing reactivity as a function of leaving group is RI > RBr > RCl. C) The order of alkyl bromide reactivity is R3CBr > R2CHBr > RCH2Br > CH3Br. D) The rate of an SN1 reaction depends on the concentration of the nucleophile. Please explain...
Please include tips and tricks for synthesis reactions in organic chemistry
Please include tips and tricks for synthesis reactions in organic chemistry
1. Why might you use a separatory funnel in an Organic Chemistry lab? What is the...
1. Why might you use a separatory funnel in an Organic Chemistry lab? What is the appropriate way to use one? 2. In an acid-base reaction, what major mechanism is being carried out?
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
Organic chemistry Gas chromatography lab questions : 1. Briefly explain the various parts of a GC...
Organic chemistry Gas chromatography lab questions : 1. Briefly explain the various parts of a GC - Injection port, oven, copper coil, and detector. 2. Identify the stationary phase and the mobile phase. 3. What is the problem with setting the oven temperature too high when programming the parameters? What is the problem with setting it too low? Thank you.
ORGANIC CHEMISTRY (TLC lab) if you used a solution of 90% ethyl acetate / 10% hexane...
ORGANIC CHEMISTRY (TLC lab) if you used a solution of 90% ethyl acetate / 10% hexane instead of 10% ethyl acetate / 90% hexane to elute your TLC plates, what would you expect to see? Would the Rf valaues increase of decrease for each compound? Explain in detail. Rf values Naphthalene = 0.44 9-fluorene 0.56 Benzophenone = 0.39 Fluorene = 0.88 4-nitroaniline = 0.28 4- methoxyacetophenone = 0.24
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT