Question

You carry out a reaction that yields a major product Q (boiling point: 120°C) and side product R (boiling point: 150°C). The ratio of Q to R is 70:30. Both Q and R are liquids. m) You use ethyl acetate (0.902 g/mL) to act as an extraction solvent. What are three main criteria for the liquid/liquid extraction organic solvent based on the lecture notes? (3 pts) What layer will ethyl acetate be at? (upper/lower) (1 pt) n) Q and R will be soluble in the organic layer (ethyl acetate) – any residual inorganic material was removed by water. Provide two ways you remove water from the organic layer. (2 pts) o) After the ethyl acetate is evaporated, Q and R (a mixture of liquids) remain. What criteria does this mixture have to satisfy to be separated by simple or fractional distillation (besides bp difference and composition)? (1 pt) p) What kind of distillation would you carry out (simple or fractional) and why? (3 pts) q) What parts of the microscale kit (seen on page 12 in the textbook) that you use for the distillation you pick that you don’t use for the alternate distillation (the one you didn’t pick)? (3 pts)

Answer 1

Answer:

Here's what I get  

Explanation:

1. Requirements for a liquid/liquid extraction solvent

(a) Distribution Coefficient

The solute must be more soluble in the solvent (the extract phase) than in the raffinate phase (the other liquid).

(b) Insolubility

The solvent and the other liquid must be mutually immiscible. This means they will form two layers in the separatory funnel.

(c) Removability

It must be easy to separate the solvent from the solutes. This usually means the solvent must have a much lower boiling point than the solutes.

2. Extract layer

The density of ethyl acetate is 0.920 g/mL.

The density of water is 1.00 g g/mL.

The ethyl acetate layer will be on the top.

3. Separability of mixture

Two miscible liquids must have a boiling point difference of at least 40 °C to be separable by simple distillation.

4. Type of distillation  

The boiling point difference is only 30°C, so you must use fractional distillation.

5. Apparatus

Your microscale kit must include an air condenser or a fractionating column.  

Perhaps it looked like the fractionating head in the kit in Fig. 1.

The alternate distillation (simple distillation) would use a distillation head like that in Fig. 2.