Please help me Sketch a separation scheme showing how you would separate the following two component mixture: m-nitroaniline and hexanol. All the substances are soluble in ether. You can use any of the following solutions in your separation: aqueous hydrochloric acid, aqueous sodium bicarbonate, and aqueous sodium hydroxide. Thanks
1. dissolve mixture in ether
2. transfer to separating funnel
3. shake mixture with aqueous HCl
4. separate and save aqueous
5. repeat 3-4 twice more
6. wash organic phase with bicarbonate solution
7. separate, discard aqueous and transfer organic phase to a flask [this now contains the hexanol as a solution in ether]
8. pour acid solution from steps 3-5 into a separating funnel.
9. add aqueous NaOH until alkaline (use pH paper)
10. extract with ether and save organic phase
11. repeat 10. twice. [the extract has a solution of the analine in ether]
12. evaporate the ether from the two solutions to recover the two substances.
There is no mention of a drying agent. In both cases you would use a drying agent to remove water traces before evaporating the ether.
I can't draw the scheme on here but these are the major steps.
To separate the mixture of m-nitroaniline and hexanol using the given solutions, we can follow the steps below:
1. Start by adding the mixture of m-nitroaniline and hexanol to a separating funnel. Make sure to measure and record the approximate amounts of each compound in the mixture.
2. Add a suitable amount of ether to the separating funnel containing the mixture. Ether is chosen as the solvent because both m-nitroaniline and hexanol are soluble in it.
3. Gently shake the separating funnel for a few minutes to ensure thorough mixing of the components. This helps in dissolving both m-nitroaniline and hexanol in the ether.
4. After shaking, allow the separating funnel to rest for a short period, allowing the layers to separate based on their densities. The layers will form with the denser layer (aqueous layer) at the bottom and the lighter layer (ether layer) on top.
5. Once the layers have settled, carefully open the stopcock of the separating funnel and drain the aqueous layer (bottom layer) into a separate container. This aqueous layer will contain any water-soluble impurities, such as traces of acids or bases present in the original mixture.
6. Close the stopcock and take the remaining ether layer. This layer will contain both m-nitroaniline and hexanol.
Now, we need to follow a series of treatments using the provided solutions to separate m-nitroaniline and hexanol from the ether layer:
7. Transfer the ether layer to a clean container, and add a small amount of aqueous hydrochloric acid. Gently shake the container for a few minutes. The purpose of adding hydrochloric acid is to protonate the m-nitroaniline, converting it into a water-soluble salt while leaving hexanol unaffected.
8. Once the shaking is complete, allow the layers to settle again. The layers will separate, forming a new bottom aqueous layer and a top organic layer. Carefully drain the aqueous layer (containing the protonated m-nitroaniline) into another container.
9. To the remaining organic layer (containing hexanol), add a small amount of aqueous sodium bicarbonate. Gently shake the container for a few minutes. The purpose of adding sodium bicarbonate is to neutralize any remaining acid and remove acidic impurities from hexanol.
10. Allow the layers to settle, and again drain the bottom aqueous layer (containing byproducts of the reaction between sodium bicarbonate and acid) into a separate container.
11. Lastly, transfer the remaining organic layer (containing hexanol) to a clean container. At this point, hexanol should be isolated from the original mixture.
12. To recover m-nitroaniline, we need to convert it back to its free base form. Add a small amount of aqueous sodium hydroxide to the separated protonated m-nitroaniline from step 8. Gently shake the container for a few minutes to deprotonate the m-nitroaniline salt.
13. Allow the layers to settle, and drain the aqueous layer (containing the deprotonated m-nitroaniline) into a separate container.
Now, you should have successfully separated m-nitroaniline, hexanol, and any impurities using the given solutions and solvent. It is important to note that the actual amounts and concentrations of the solutions used will depend on the specific quantities and properties of the mixture being separated.