What is distillation?

The process of separating the components of a liquid mixture through selective evaporation and condensation.

Identify the simple breakdown of steps when doing a distillation. Distillation set up

What is a simple distillation?

What are the two cases where it is possible to get a good separation by using a simple distillation?

What is fractional distillation? When should it be used?

Be able to identify the following parts on a simple & fractional distillation apparatus: distilling flask, distilling head, fractional distillation column, condenser, vacuum adapter, and receiving flask.

Azeotrope mixture

Purpose of adding boiling chips.

Distillation is the separation of multiple ___ components based on their ___. As the mixture is heated and the first component ___, its ___ form travels through the distillation set-up and ___ into a different container.

- liquid

- boiling points

- boils

- vapor

- condenses

To insert a thermometer into an adapter, use ___ to prepare the thermometer. Then, hold the thermometer ___ the adapter and ___ the thermometer into the adapter.

- mineral oil

- close to

- slowly turn

What are the concerns presented by overheating a distillation to a dry flask?

- The remaining solid residue might contain explosive peroxides.

- The empty glassware might heat quickly, igniting vapors from the distillation.

Before turning on the heat for a microscale distillation, what should you confirm about the set-up?

- Existence of some opening in the set-up.

- Secure connections at the joint.

- Presence of boiling chip in the sample.

Where should the tip of the thermometer be placed in a microscale distillation set-up?

At or slightly below the sidearm of the distillation head.

An azeotrope is a mixture that has ___ composition in the ___. Therefore, an azeotropic mixture ___ be separated by distillation.

- the same

- gas and liquid phases

- cannot

Suppose you are using distillation to separate cyclohexane and toluene. The boiling point of cyclohexane is ___ and the boiling point of toluene is ___. Therefore, the liquid collected first should be ___.

- 81°C

- 111°C

- cyclohexane

Summary flow chart of the separation of 3-nitroaniline, benzoic acid, and naphthalene.

In a separatory funnel, which layer is top layer and which layer is bottom layer? Why?

How can you separate an organic acid and an organic base using separatory funnel?

Determine which base will work to deprotonate each compound in an acid/base extraction.

Determine which base will work to deprotonate each compound in an acid/base extraction.

Determine which base will work to deprotonate each compound in an acid/base extraction.

Leaves impurities in their starting layer.

Extraction

Often involves a reaction in one of the layers.

Extraction

Moves desired compound from one layer to another.

Extraction

Moves impurities from one layer to another.

Wash

Leaves desired compound in its starting layer.

Wash

Suppose you are performing an extraction procedure with a carboxylic acid, like a benzoic or toluic acid.

Which layer should contain the carboxylate in a two-layer mixture of water and an organic solvent, like diethyl ether?

The organic layer

You then add a base to form the corresponding carboxylate.

Which layer should contain the carboxylate in a two-layer mixture of water and an organic solvent, like diethyl ether?

The aqueous layer

What is the purpose of a drying agent in the work up of an organic reaction?

To absorb small amounts of water in an organic solution

When using acids and bases, note that these substances are ___. Make every effort to avoid contact with ___. Be sure to wipe up any spills ___.

- corrosive

- the skin and lab surfaces

- immediately

Aniline involves an amine, which is a ___ functional group. When an aqueous acid solution is added to an organic solution including aniline, the aniline appears in the ___ layer in its ___ form. Then, a base is added to ___ the aniline.

- basic

- aqueous

- protonated

- reconstitute

Extract reconstituted 3-nitroaniline out of the aqueous layer.

Dicloromethane

Extract aniline into the aqueous layer.

5% HCl solution

Reconstitute benzoic acid from aqueous layer.

6M HCl

Extract reconstituted benzoic acid out of the aqueous layer.

Dicloromethane

Extract benzoic acid into the aqueous layer.

5% NaOH solution

Reconstitute aniline from aqueous layer.

6M NaOH

What hazards are associated with naphtalene?

- Naphtalene is flammable.

- Naphtalene is toxic.

- Naphtalene produces nauseating vapors.

Percentage recovery calculation.

% recovery = (amount recovered/starting amount) x 100

Before adding a sample or solvent into a separatory funnel, what should you have in place?

- A funnel in the top of the separatory funnel.

- A flask under the separatory funnel.

- A stopcock in the closed position.

To determine the layers in a separation of organic and aqueous solutions, you can add a small amount of ___ to the top. If the top layer is aqueous, the addition will ___ the top layer. If the bottom layer is aqueous, the addition will ___ the top layer and ___ the bottom layer.

- water drops

- combine with

- travel through

- combine with

What is the purpose of the brine wash?

To reduce the amount of water in the organic solution.

What is the visual indicator that enough of a drying agent, such as anhydrous MgSO₄ or CaCl₂, has been added to properly dry an organic solution?

The drying agent will move freely like a powder around the solution.