Question

If you are provided with a mixture containing an amine compound e.g. R-NH₂ and a neutral compound e.g. biphenyl, show using a flowchart how you would successfully separate the mixture to obtain the two pure compounds.

Answer 1

According to the question;

As we know that;

The mixture of a neutral compound and an amine can be separated by extraction with HCl.

Since, HCl is an acid it reacts with amine and forms its conjugate which is present in ionic form while HCl does not react with neural compound. Since conjugate of amine is ionic, it dissolves in water.

So,

Neutral compound does not dissolve in water and hence it remains in organic layer. The separation can be better explained by the flow chart.

Then,

Mixture (dissolved in organic solvents)Extract with HCl

Organic layer (neutral compound) aqueous layer (amine)

Evaporate solvent neutralization

Neutral compound amine