Question

A mixture of compounds containing diethylamine, phenol, ammonia, and acetic acid is separated using liquid-liquid extraction as follows: Step 1: Concentrated HCl is added followed by draining the aqueous layer. Step 2: Dilute NaOH is added to the organic layer followed by draining the aqueous layer. Step 3: Concentrated NaOH is added to the organic layer followed by draining the aqueous layer. Which compound would you expect to be extracted into the aqueous layer after the addition of dilute NaOH, step 2?

Answer 1

Answer:

I would expect to extract the acetic acid.

Explanation:

In the first step, since we are adding a concentrated acid, it will react with the bases present in the mixture (diethylamine and ammonia) forming salts, which are soluble in water. Therefore, after draining the aqueous layer, we will have phenol and acetic acid left in the organic layer.

In the second step, we are adding a diluted base, so it will react with a strong acid. This compound is acetic acid, and its salt will be present in the aqueous layer. Phenol will be left on the organic layer.