Acid base Extraction

Essay by AkeCollege, UndergraduateA-, October 1996

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The purpose of this laboratory assignment was two-fold, first, we were to

demonstrate the extraction of acids and bases, finally, determining what unknowns were

present. Second, we were to extract caffeine from tea. These two assignment will be

documented in two separate entities.

Introduction: Acid/base extraction involves carrying out simple acid/base reactions in

order to separate strong organic acids, weak organic acids neutral organic compounds

and basic organic substances. The procedure for this laboratory assignment are on the

following pages.

3) Separation of Carboxylic Acid, a Phenol and a Neutral Substance

The purpose of this acid/base extraction is to separate a mixture of equal parts of

benzoic acid(strong acid) and 2-naphthanol(weak base) and

1,4-dimethoxybenzene(neutral) by extracting from tert-butylmethyl ether(very

volatile).The goal of this experiment was to identify the three components in the mixture

and to determine the percent recovery of each from the mixture.

4) Separation of a Neutral and Basic Substance

A mixture of equal parts of a neutral substance containing either naphthalene or

benzoin and a basic substance containing either 4-chloroaniline or ethyl 4-aminobenzoate

were to be separated by extraction from an ether solution.

Once the separation took

place, and crystallization was carried out, it became possible to determine what

components were in the unknown mixture, by means of a melting point determination.


Procedure Observations Inference

Dissolve 3.05g Phenol Mixture was a golden-

Neutral acid in 30ml brown/yellow color

t-butyl methyl ether in

Erlenmeyer flask and transfer

mixture to 125ml separatory

funnel using little ether to

complete the transfer

Add 10 ml of water Organic layer=mixture

aqueous layer=water(clear)

Add 10 ml saturated aqueous Sodium bicarbonate NaHCO3 dissolves in

solution sodium bicarbonate water.

to funnel and mix cautiously

with stopper on

Vent liberated carbon Carbon dioxide gas

dioxide and shake the mixture was released three times

thoroughly with...