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A student was given 1.5 g of 1:1:1 mixture of the following compounds. By using

ID: 899874 • Letter: A

Question

A student was given 1.5 g of 1:1:1 mixture of the following compounds.

By using extraction, the student aims to separate and purify the above mixture. Fill in the blanks in the procedure by using the following pool of compounds/reagents/solvent. You do not necessarily have to use all the structures in the pool.

Procedure: The 3-component mixture was dissolved in 30 mL ether and poured into a separatory funnel, then 10 mL of 10 % HCl was added. After mixing/venting the separatory funnel, two layers formed with the top ether layer containing A)………………………and B)………………………….. and with the bottom aqueous layer containing C)…………………………………….The bottom acidic extract was drained out into a beaker and made basic with D)……………………….. until pH 12 to obtain E)…………………. as a precipitate.

            To the remaining top organic layer in the separatory funnel, 5 mL 6 M NaOH was added and the separatory funnel was mixed and allowed to stand. This resulted in two layers: the top organic layer containing F)…………………………..and the bottom aqueous layer containing G)……………..

The bottom basic extract was drained out into a beaker and acidified with 10 % HCl to yield H)…………………………. as a precipitate.

OH NH2 0 hexanoic acid naphthalene 2-phenylethanamine

Explanation / Answer

The answers are bold and underlined

Procedure:

The 3-component mixture was dissolved in 30 mL ether and poured into a separatory funnel, then 10 mL of 10 % HCl was added. After mixing/venting the separatory funnel, two layers formed with the top ether layer containing A) Hexanoic acid and B) Naphthalene and with the bottom aqueous layer containing C) 2-phenylethylamine hydrochloride salt. The bottom acidic extract was drained out into a beaker and made basic with D) 6 M NaOH until pH 12 to obtain E) 2-phenylethylamine as a precipitate.

To the remaining top organic layer in the separatory funnel, 5 mL 6 M NaOH was added and the separatory funnel was mixed and allowed to stand. This resulted in two layers: the top organic layer containing F) Naphthalene and the bottom aqueous layer containing G) Sodium hexanoate.

The bottom basic extract was drained out into a beaker and acidified with 10 % HCl to yield H) Hexanoic acid as a precipitate.