Distillation Lab
How Distillation Works
• Distillation separates liquids based on their
different boiling points.
• Liquids are boiled and then recondensed in a
separate location.
• Water is distilled to remove its impurities.
• Processing of crude oil is mostly distillation.
Gases like propane boil off at less than 40oC,
gasoline boils off from 40-200oC, kerosene boils
off from 2-300oC, diesel boils off from 250350oC, etc.
Lab Procedures I
1. Remove the 250 ml round bottom flask.
2. Use the graduated cylinder to add 25 ml of
isopropanol and 25 ml of tap water.
3. Add 4 fresh boiling chips and 2 drops of food
color.
4. Reconnect the 250 ml flask.
5. Turn on the water as low as possible.
6. Turn on the hot plate as high as possible.
7. Place a bowl of ice water around the collection
flask.
Lab Procedures II
6. Set up the temperature probe on the Labpro.
7. Set the temperature probe at the intersection
above the boiling flask.
8. *Record the time, temperature and
observations every 60 seconds in each
individuals notebook.
9. *Sketch the distillation apparatus between
measurements and figure out the role of water.
10. The temperature will flatten out while boiling
for several minutes.
11. When it rises 3 more degrees, turn off the heat
and move the hot plate to stop the boiling.
Lab Procedures III
10. Place the collected distillate in the
collection bottle labeled 88%
Isopropanol.
11. Place the colored liquid remaining in the
boiling flask in a bottle labeled “Waste
Bottoms.”
12. Reattach all the flasks securely.
Lab Analysis
• Prepare a graph using Excel. Select XY
scatter and connect the dots with curved
lines.
• Label observations on your graph with text
boxes.
• Print and tape a copy of the graph in each
person’s lab notebook.
• Answer the following questions in your lab
notebook.
Distillation Lab Questions
1. Describe the physical changes that
isopropanol does in order to move to the
collecting flask.
2. What is the role of water from the faucet?
3. How is the isopropanol extracted or purified
from the water & food color in this process?
4. Find out 3 uses of distillation.
5. What are the manipulated and responding
variables in distillation?
Teacher Notes
• High output hot plates are required.
• Temperature probes need clay or electricians tape to
seal the top.
• Set up each distillation apparatus to rest ¼ or ½ inch
above the hot plate with enough room to put ice baths
below the collecting flasks. Use bricks from Phys under
low hot plates.
• Prepare used isopropanol to distill by taking 1 part of
88% isopropanol and mix with 1 part of water.
• Waste bottoms are primarily food coloring and water with
a small amount of isopropanol.
• Use black rubber hoses for water connections.
Water cools the
vapor to liquid In the
condensing tube.
Thermometer
measures vapor
Excess pressure
is released out
opening.
Isopropanol boils
At 82.5oC, water at
100oC, food color?
44% isopropanol
boiling chips
Food coloring
Ice
condenses
last of vapor
to
minimize
escape.