Expt5.0-RecrystallizationOnlineFall2020-studentVersion.docx...

Expt 5.0 Recrystallization- A Purification Technique
Objective:
In this experiment, you will simulate a recrystallization of 4-nitroaniline, an organic solid. Data will be provided so that
you can calculate quantities of solvent needed for your experiment and to calculate a percent recovery.
Before you begin:
 Read Expt 5.0-Recrystallization in the Laboratory Manual for Organic Chemistry Chem 231/241L
 Watch both YouTube videos on recrystallization and vacuum filtration
(recrystallization)
(vacuum Filtration)
Structures for impure solid and potential recrystallizing solvents.
Solid to be
Recrystallized
Structure of
solid
Possible
recrystallizing
solvents
Structure of
solvent
4-nitroaniline
cyclohexane
toluene
ethanol CH
3
CH
2
-OH
water H
2
O
Solvent screening: Notes and observations from lab notebook to determine best solvent choice.
cold = room temp hot = beaker with boiling water (100ºC)
cyclohexane toluene ethanol water
cold hot cold hot cold hot cold hot
did not
dissolve with
vigorous
shaking
not soluble
after several
minutes of
heating
did not dissolve
with vigorous
shaking