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.
Ball and stick model of the benzoic acid molecule.
English: Crystals of pure benzoic acid, recrystall...
Victim of AcidificationOnce 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.
Results
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...