Separating Acids and Neutral compounds by solvent extraction
Suppose that you used dichloromethane instead of tert-butyl methyl ether as the nonpolar solvent in this experiement. What changes in the procedure would you make in view of the fact that dichloromethane is more dense than water.
The extracts would have to be removed from the separating funnel with a pipet because the dichloromethane would collect at the base of the separating funnel and the NaHCO3 and NaOH solutions, on top of the dichloromethane. you would need to extract the top layer from above, leaving the bottom layer intact for further washes.In other words, you would save the opposite layer. If you used dichloromethane, you would save the bottom layer (MeCl2) and discard the aqueous top layer.
in which layer would p-toluic acid be more soluble if p-toluic acid were added to a two-layer mixture of tert-butyl methyl ether and water
- it would be more soluble in tert-butyl methyl ether.
what is the difference between extraction and washing
-Extraction is pulling the desired compound out of a mixture of compounds. - Washing is pulling unwanted impurities away from the desired product
What two visible evidence of reaction will you see when you acidify the NaHCO3 extract with HCl solution
-one result of the reaction will be carbon dioxide bubbling out of solution -Also sodium chloride can be viewed falling in the solution.
Macroscale process
1) Dissolve acetanilide, p-toulic acid, and pert-butylphenol in t-butyl methyl ether 2) Extract p-toulic acid from the ether layer with NAHCO3 solution, separating the layer. 3) Extract p-tert-butylphenol from the ether layer with NaOH solution, separate the layers 4) Isolate p-toulic acid by adding HCl solution to the aqueous NaHCO3 layer 5) Isolate p-tert butylphenol by adding HCl solution to the aqueous NaOH layer 6) Isolate acetanilide by drying the ether solution, then evaporating t-butyl methyl ether in a fume hood. 7) Dry the isolated compounds and measure their masses 8) Measure the melting point of each compound and compare to literature value
Extraction
Is a process that selectively dissolves one or more of the mixture compounds into an appropriate solvent.
what product would you obtain if you evaporated the water from the NaOH layer prior to acidifying the layer?
if one evaporated the water from the NaOH layer prior to acidification, the p-tert-butylphenocide anion (the sodium salt of p-tert-butylphenol) would have been obtained.
extract
is the solution of these dissolved compounds
Too much heat heat causes acetanilide to
sublime. when the ether has evaporated a small amount of oil will remain.
tert-butyl methyl ether hazards
It is highly flammable liquid and a fire hazard Breathing tert-butyl methyl ether can irritate your nose and throat. Exposure to it may cause headache,nausea,weakness and lightheadness It can effect liver and kidneys
Densities
ether or hydrocarbon < water< dichloromethane
3M HCL hazards
Acid is highly corrosive, and concentrated forms release acidic mists that are also dangerous. It may burn your skin,damage your eyes badly when contacted directly with high concentration when inhaled it may damage your internal organs and can be fatal in severe cases
what would happen of you first extracted the ether solution with aqueous NaOH solution instead of aqueous HCl? Would this make any difference in the overall results?
Ether solution with aqueous NaOH nothing much difference will come, And you can see the layer separation
How would the results differ if you added sodium p-toluate instead of p-toluic acid to the two-layer mixture of tert-butyl methyl ether and water?
Found in the water layer
if you mistakenly extracted the ether solution first with NaOH solution and then with NaHCO3 solution, no crystals would be produced upon acidification of the NaHCO3 layer. Briefly explain
I believe the answer is that if you extract with NaOH, since it is a stronger base, it will extract all the compound you are trying to extract, leaving none behind to extract with the NaHCO3. Therefore, when acidifying the NaHCO3 layer, there will be no organic compound ion in it
The solvents selected must be
Immiscible, or not soluble in one another, so that they produce two separate solvent layers.
Salting out
Inorganic salts are dissolved in water to reduce the solubility of the organic compound in the aqueous layer.
briefly explain how you will isolate p-tert-butylphenol after you have extracted it into NaOH solution.
To isolate p-tert-butylphenol after you have extracted it into NaOH solution one would precipitated the p-tert-butylphenol by adding 3M HCl to the cooled solution until it is acidic. then as the phenol separates as an oil, one needs to cool the mixture in an ice bath to facilitate crystallization. The crystal that are then formed are the p-tert-butylphenol which can be separated from the solution by filtration using the hirsch funnel.
why would NaOH extract be heated before acidification?
To remove any remaining traces of tert-butyl methyl ether that might inhibit the crystallization of the phenol
Purpose of the experiment
Use solvet extraction technique to separate a mixture consisting of a carboxylic acid, a phenol, and a neutral compound.
