Lab 3: Chemistry of Whisky
Whisky is an alcoholic drink made of fermented malt or cereal grains that have been distilled then aged
in oak barrels. The most important step of making whisky aroma and taste is the barrel aging process
Distillation – The process of separating a mixture based on Boiling points. This a very useful process for
the purification of liquids
2 Types: 1) Simple Distillation
2) Fractional Distillation
Distillation involves 3 steps
1) The Vaporization of a liquid
2) The Condensation of Vapour
3) Collection of a Pure Liquid Component
When do use simple and fractional distillation
Temp change > 25 Simple distillation
Temp change <25 Fractional distillation
In fractional distillation a fractionating column is placed in between the distillation flask and the
distillation head. This column usually contains steel or copper sponge. The fractionating column enables
improved separation by providing extra surface area surface area for condensation of the solvent
vapors. This results in many vaporization- condensation cycles before collection cycles before collection
of the pure liquid, which improves the separation.
Fractional Distillation requires patience because of a slow rate of distillation is needed for good
Simple Distillation Fractional Distillation Experimental Plan:
Part 1 Simple distillation
1. Put unknown into a round-bottom flask with a few boiling stones.
2. Begin boiling at a rate at which you get a approx one drop per second.
3. Record temp every time 1ml is collected
4. Boil till 20ml is collected.
Part 2 Fractional Distillation
1. Mark ten test tubes and approx about how much 2ml of liquid would be in each.
2. Begin boiling and collect 2ml into each test tube (boil at a rate of at no more than 20 drops per
3. Record the temp every time 1 mL was collected
4. Using the temps recorded from fractional distillation (due to it being more precise) figure out your
5. Gather a IR spectrum and that should help find your two types of pure components which leads to
the finding of your unknown whisky compound.
What you should have got out of this lab
When choosing the right temps you were looking for the ones where the was little to know change
between the test tubes and there should have been 2 times the values obtained were almost identical
and those should have been the test tubes used when running your tests and obtaining your IR
When calculating your corrected boiling point remember
( ) ]0.5
And the C.F. value should be added to the boiling points attained. Exp. 4: The Chemistry Behind Decaffeinated Coffee:
Coffee trees belong to the Rubiaceae family of flowering plants.
The main chemical compound component in coffee beans is caffeine, an alkaloid that stimulates the
nervous system. Additionally coffee also consists of proteins, lipids, chlorogenic acid and aliphatic acids.
Some of these substances possess some antioxidant activity and have been known to act as anti-
inflammatory and anti-carcinogenic agents.
Decaffeination – A process in which you would extract caffeine from the coffee bean before the roasting
1) Swiss Water Process
2) Direct Process ( One of the oldest methods)
3) Indirect Process
4) The CO P2ocess
Direct Process – A solid liquid extraction is used to remove the caffeine from the green coffee beans by
using DCM or Ethyl Acetate.
WE USED TO THE DIRECT PROCESS AS DECAFFINATION OF THE COFFEE IN THIS LAB
Solid-Liquid Extraction – Involves the withdrawal of a desired substance from a substance from a solid
using a liquid solvent. In this process one should use a hot solvent should be used to leach out
compounds from the solid. The Solid and solvent should be heated together in a reflux, this allows for
leaching as well as maintaining the solvent at a constant increasing temp.
IN ORDER TO OBTAIN THE CRUDE COMPONENTS OF A PLANT, THE SOLVENT MUST BE EVAPORATED
FOLLWING EXTREACTION. In order for coffee to be considered “decaffeinated” by FIFDA rules requires the coffee contains Less
than 30mg of caffeine.
Part 1 Extract caffeine from coffee
1. Add the coffee into the round bottom flask
2. Add 30m