Distillation and
Chromatography
Objectives
• Separate the components of a solution
using distillation and chromatography
• Determine physical or chemical properties
which proves separation was successful
• Determine Vapor Temperature variations
during the distillation.
An Introduction to
Separations
What is Separation
• The division of chemical mixtures into its
chemical components by physical means.
• A single substance that has no other
substances mixing with it is called a PURE
SUBSTANCE. If there is something else
mixed with it, it is a mixture.
Why Separations
• Most Chemicals are natural products that
must be separated into pure chemicals for
use in industry or research.
How to Separate
• Separations are achieved through
mostly physical means.
• All chemicals have different physical
characteristics.
• The differences in the physical
properties are exploited to separated
different molecules.
Example Physical Properties
•
•
•
•
•
•
Boiling point
Melting point
Charge state
Partition Coefficient
Vapor Pressure
Solubility
Physical Properties of C2
Molecules
Chemical Name Formula Mw
Mp
Bp log Kow pKa
Ethanol
C2-H6-O 46.07 -114.1 78.5
-0.31
15.9
Acetic acid
C2-H4-O2 60.05 16.6 117.9
-0.17
4.76
Aetaldehyde
C2-H4-O 44.05 -123.5
21
13.57
Ethylamine
C2-H7-N 45.08 -81.2 16.6
-0.13
10.87
Types of Separations
•
•
•
•
•
Re-crystallization
Selective Precipitation
Solvent extraction
Electrophoresis
Distillation
•
•
•
•
Chromatography
Field Flow Fractions
Super Critical Fluid
Hyphenated methods
Introduction to Chromatography
The Master
British biochemist Richard Synge won
the 1952 Nobel Prize in chemistry. He
developed partition chromatography, a
technique for identifying and
quantifying the component parts of
such substances as proteins,
carbohydrates, and nucleic acids.
Elements necessary for
Chromatography
•
•
•
•
Mobile Phase
Stationary Phase
Sample inlet
Detection
Types of Chromatography
Chromatography
Gas
Gas Solid Column Gas Liquid Column
Liquid
Column
HPLC
Paper
Thin Layer
Types Of Adsorption Packings
•
•
•
•
•
•
•
•
Paper
Cellulose
Starch
Sugars
Magnesium Silicate
Calcium Sulfate
Silicic Acid
Silica Gel
•
•
•
•
•
•
Florisil
Magnesium Oxide
Aluminum Oxide
Activated charcoal
ODS
Synthetic packing
Thin Layer Chromatography
Developing Chromatograph
Liquid Column Chromatography
The Packed Column
High Pressure Liquid
Chromatography
Distillation is…
• The separation and purification of
a mixture of components based on
the different volatilities of each
component.
• The volatile components are
vaporized, then condensed, and
collected.
What is in our mixture?
1)
2)
3)
4)
Water
Ethanol
Red Dye
Blue Dye
Volatility
Water is less volatile than ethanol
because water’s intermolecular
forces are stronger than those of
ethanol.
Phase Equilibrium
Temp
vapor
80º
liquid
%Ethanol
%Water
100
83%
0
17%
50
67% 0
50
33% 100
Modifications to Procedure
•
•
•
•
•
•
•
•
1 ml direct pipette with pump
Small plastic beaker for density determination
Dye Mixture
Plastic graduated dropper for food dye
Ice
Large beaker for Ice Bath
Chromatography Kit
4 vials for each component isolated
Procedure modifications
• Prepare a solution containing 25 % V/V Ethanol
Water Solution
• Volume of solution prepared should not exceed
25 % of volume of pot Flask
• Determine Volume by the following Equation
• Volume of Pot Flask * .25 = Total Volume of
solution prepared
• Using a Pipette and Balance determine the
density of the solution prepared
Chromatography Analysis
• Wet the column using eluent which is
designated as the most polar
• Place the .5 ml of solution prepared into
reservoir of Column Chromatography
apparatus as demonstrated by Instructor
• Draw into column the solution
• Add the polar eluent into the column until
one of the dyes can be isolated into the
small vial provided
Chromatography continued
• Place the less polar eluent into the
reservoir above the column. Draw the
eluent into the column as instructed.
• Isolate the second dye and place into
labeled vial
Distillation
• Using Logger pro determine the temperature
which is most constant during the distillation. Do
not allow the vapor temperature to exceed 90
degrees Celsius
• Test the combustibility of the solution prepared
and the combustibility of the components
isolated
• Determine the density of the original solution
and density of the separated components.
Questions
• Answer all questions in lab
• Using the most constant temperature
reading obtained during the distillation
determine the % alcohol in the Vapor.
• Which of the Dyes is more Polar and
Attracted to the more polar Eluent