Question

Procedure

You will be provided with a mixture of TWO of the following three organic components dissolved in diethyl ether. If present, they are present at the concentrations given below:

Benzoic acid, 0.20 M

Ethyl – 4-aminobenzoate, 0.20 M

Acetanilide, 0.20 M

Your goals are: (1) determine which of the above four molecules are present in the sample that was given to you and (2) isolate a sufficient quantity to determine a melting point and hand in a product.

You will be given ~20 mL of the diethyl ether solution.

You will have available: 10% HCl, 6M HCl, 10% NaOH, 6M NaOH, saturated NaCl, and drying agent.

Answer 1

benzoic acid --> HA, polar, will react with mild bases

Acetanilide --> amide, will react with acids

Ethyl – 4-aminobenzoate --> nonpolar solvent

Q1.

always start with NaOH addition -->

deprotonates benzoic acid

in aqueous solution -- > extract benzoic acid with water + Nacl in order to separate organic layer + aqueous layer.

now..

add HCl into the extracted aqueous solution --> HBenzoic acid is recovered

then

in the organic layer

add HCl

HCl reacts with the base to protoante it

this will go into aqueous solution since H+ makes it polar

then

aqueous layer --> acetanilide

organic layer --> Ethyl – 4-aminobenzoate

now..

in the organic layer, add a base, so the amide deprotonates

then, we have separate all 3 samples