Lab 3 Extractions

Purpose of lab:

To prepare and separate a 3-component mixture using acid-base extractions and learn some basic concepts relating to the purification and analysis of organic compounds

4.Acid-Base extractions

a method for separating organic compounds by manipulating their solubility using changes in pH

This experiment uses:

Acid-base extraction of a mixture of 3 compounds

Acid-Base extraction consists of:

Carboxylic acid and benzoic acid - strong acid

2-naphthol - phenol (weak acid)

Naphthalene - neutral compound

First Extraction

Sodium bicarbonate (weaker base) and sodium hydroxide (strong base)

Second Extraction

The neutral compound remains in the upper ether layer, where the deprotonated phenol now dissolves in the lower aqueous layer

Extraction using :

vacuum filtration and separation

Acid -base

extractions utilize the difference in solubility of a compound, when the organic compound becomes ionic,  it becomes more water soluble.

2-Naphthol (weak acid)

soluble in diethyl ether and sodium hydroxide but not sodium bicarbonate b/c its is a weak acid

Chemicals needed:

10% sodium hydroxide, 5% sodium bicarbonate, 6M HCl, Diethyl ether, and anhydrous sodium sulfate

Vacuum filtration setup

hirsch funnel, 25ml side arm filtration flask, and ring stand

Glassware needed:

10 mL graduated cylinder, 10 mL beaker, 150 mL beaker, and 5 mL conical vial

Other items needed:

Ring/clamp stand, pH paper, filter paper, ice bath, and centrifuge tubes