Question

The Separation of Three Organic Compounds by Acid, Base Reactions and Liquid, Liquid Extraction.

Okay, so we had solid benzoic acid, ethyl 4- aminobenzoate, and 9-fluorenone all dissolved in diethyl ether. We separated the basic component by adding 3M HCl, we separated the acidic component by adding 3M NaOH. I don't understand what happens here. To isolate the acidic solution, we added 6 M NaOH and used the vacuum to recover the solid. To isolate the basic solution we added 6M HCl. I did an experiment where a 1:1:1 mixture of Benzoic Acid solid (C6H5COOH), ethyl 4-aminobenzoate solid (C9H11NO2), and 9-fluorenone solid (C13H8O) was dissolved with methylene chloride. Then each component was extracted and tested. I need to come up with a proton transfer chemical reaction that represents what happened in each separation. First separation: HCl was added and two layers formed. aqueous layer was extracted and transfer to a clean container and methylene chlotide layer was left aside. NaOH was added dropwise to aqueouse layer extraction and vacuum filtration was used to extract/separate the basic component ethyl 4-aminobenzoate solid (C9H11NO2).

Results &Data:

1)Benzoic acid (Acid)

Benzoic acid	0.051g
Tare dish	0.419 g
Dish with Solid (Benzoic acid)	0.443 g
Dry mass obtained (Final product after vacumming)	0.441 g
Melting point	97.0 °C – 97.2 °C

Table 1: Collected data from Benzoic acid

2) Benzoate (Base)

Benzoate	0.050 g
Tare dish	0.406 g
Dish with Solid (Benzoate)	0.413 g
Dry mass obtained (Final product after vacumming)	0.408 g
Melting point	78.0 °C – 79.4 °C

Table 2: Collected data from Benzoate.

3) 9-Fluorenone (Neutral)

9-Fluorenone	0.050 g
Tare tube	11.360 g
Dry mass obtained (Final product after drying)	11.470 g
Melting point	89.4 °C – 89.5 °C

Table 3: Collected data from 9-Fluorenone.

I need to find the theoretical and percent yield of each product, how many mg of each product is present. And also create 4 chemical reactions. Need help, Please help thankyou

Answer 1

Solution of mixture of benzoic acid, 4-aminobenzoate and 9-fluorenone in dichloromethane or diethyl ether, when treated with 3M HCl, basic component i.e. 4-aminobenzoate dissolves in aqueous HCl layer. The other two components remain in DCM or diethyl ether layer. The reaction of 4-aminobenzoate with HCl can be shown as given below:

The aqueous layer when treated with 3M NaOH, 4-aminobenzoate regenerate, which can be filtered off and dried. The reaction can be shown as given below:

The organic layer containing remaining two components, upon treatment with 3M NaOH loses benzoic acid to aqueous layer as a sodium salt. The reaction can be shown as given below:

The aqueous layer containing sodium salt of benzoic acid upon tretment with HCl regenerates benzoic acid, which can be filtered off and dried. The reaction can be shown as given below:

The remaining components i.e. 9-fluorenone is in organic layer. Organic layer can be evaporated to get 9-fluorenone.

Given mixture contains 0.051g of benzoic acid, 0.050g of ethyl-4-aminobenzoate and 0.050g of fluorenone. Thus, theoretical yield of benzoic acid should be 0.051g, theoretical yield of ethyl-4-aminobenzoate should be 0.050g and theoretical yield of 9-fluorenone should be 0.50g. Weight of separated components from given data can be calculated as follows:

Weight of separated benzoic acid = final weight - tare weight

Weight of separated benzoic acid = 0.441g - 0.419g

Weight of separated benzoic acid = 0.022g

Similarly weight of ethyl-4-aminobenzoate can be calculated as follows:

Weight of separated ethyl-4-aminobenzoate = 0.408g – 0.406g

Weight of separated ethyl-4-aminobenzoate = 0.002g

Similarly weight of 9-fluorenone can be calculated as follows:

Weight of separated 9-fluorenone = 11.470g – 11.360g

Weight of separated 9-fluorenone = 0.110g

Thus, percent yields can be calculated as follows:

Percent yield of benzoic acid = (practical yield / theoretical yield) x 100

Percent yield of benzoic acid = (0.022g / 0.051g) x 100

Percent yield of benzoic acid = 43%

Percent yield of ethyl-4-aminobenzoate = (0.002g/0.050g) x 100 = 4.0 %

Percent yield of 9-fluorenone = (0.110g / 0.050g) x 100 = 220%

Percent yield indicates that separation has not taken place effectively.