Distillations
I, II, and III
Introduction:
Distillation
is a common method used to separation completely the components of a solution.
It is an application of the following principle: If the substances present in a
solution are not equally volatile, the solution vapor will have a different
composition from that of the original solution and separation can be
accomplished by catching and condensing the vapor. If one substance is volatile
and the other is not, the separation may be complete. If both substances are
volatile, but not equally so, the separation will be only partial but the
distillate (the product) will be richer in one of the components that the
original solution was.
Objectives:
1. To determine the distillate between three
different of mixtures.
2. To determine the % of alcohol in a water-
alcohol mixture by distillation.
3. To determine the difference between tap water
and distilled water.
Materials:
1. Distillation apparatus
2. Bunsen burner apparatus
3. Graduates, beakers, test tubes, and 25ml
volumetric flask
4. Chemicals: KMnO4, H2SO4,
NH4OH, AgNO3, HNO3, BaCl2, HCl, (NH4)2C2O4,
acetic acid, soap solution, tap water and distilled water
Distillation I:
1. Place 10 ml of KMnO4 in the
round bottom flask and add 150 ml of tap water.
2. Note the original colors of the solutions
and the color of the mixture. Add red and blue litmus paper to the mixture and
record any changes. The papers may remain in the flask during the distillation.
3. Turn on the Bunsen burner and begin
distilling the mixture. The burner should be 4-6 inches from the bottom of the
flask, and heating should be gentle. Place a 50-ml graduate under the opening
of the condenser to collect the distillate.
4. Once the mixture begins to separate
(noted by drops of distillate in the graduate), record the temperature.
5. Collect 5-10 ml and record the color of
the distillate. Test the distillate using the red and blue litmus paper and
record the results.
6. The mixture remaining in the round bottom
flask may be pour down the drain. DO NOT ALLOW the litmus paper to go down the
drain. Rinse the flask with tap water.
7. Complete steps 1 through 6 using 10 ml of
sulfuric acid
8. Complete steps 1-6 using 10 ml of
ammonium hydroxide
Distillation II:
9. Obtain a 25-ml volumetric flask. Mass it
dry and add 25 ml of the water-alcohol mixture. Mass the volumetric flask with
the mixture and record mass.
10. Pour 175 ml of the water-alcohol mixture
into the round bottom flask, set-up the distillation apparatus and record the
temperature “at the start”. Begin heating your water-alcohol mixture gently.
11. Obtain 5 50-ml beakers and label them #1
through #5. Mass each beaker dry and record mass on the data table.
12. Beaker #1 should be place below the
condenser to collect the first 30-ml of distillate. Record the temperature when
the distillate starts to drip and when the beaker has 30 ml. Switch
to Beaker # 2 and also record the temperature when the distillate starts to
drip and when the beaker has 30-ml. Continue this process until all 5 beakers
have 30–ml of distillate.
13. Mass each beaker with the distillate then
measure the volume accurately by pouring the 30-ml of distillate into a
graduate. Record volume. The distillate can be poured down the drain and the
water-alcohol mixture in the volumetric flask can be put back into the stock
container.
14. Clean up the work area.
Distillation III:
15. Obtain 9 test tubes and add 50 ml of
distilled water in a beaker.
16. Half fill one test tube with distilled
water and set it a side for comparison
17. In four test tubes half fill with
distilled water. Label # 1-# 4
18. In the remaining four test tubes half
fill with tap water. Label # 5-# 8
19. Test 1: The presence of chlorides. Add 3
drops of silver nitrate solution to test tube # 1 and # 5. Note any changes. Add
2 drops of nitric acid. Note any changes. If the precipitate does NOT dissolve,
the presence of chlorides is indicated.
20. Test 2: The presence of calcium salts.
Add 6 drops of ammonium oxalate solution to test tube # 2 and # 6. Wait 30
seconds, and then note any changes. Add 10 drops of acetic acid. If the
precipitate does NOT dissolve, the presence of calcium salts is indicated.
21. Test 3: The presence of sulfates. Add 6
drops of barium chloride solution to test tube # 3 and # 7. Note any changes.
Add 5 drops of hydrochloric acid. If the precipitate does NOT dissolve, the
presence of sulfates is indicated.
22. Test 4: Hardness of water. Add soap
solution to test tubes # 4 and # 8, one drop at a time with shaking after each
drop is added. Count the number of drops needed to make lather. The amount of
soap needed to make lather is a measure of the hardness of the water.
Data Tables:
Distillation I:
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Trial |
Before distillation |
After distillation |
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Color of each substance |
Red litmus |
Blue litmus |
Temp |
Color of distillate |
Red litmus |
Blue litmus |
What was the distillate? |
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1 |
KMnO4 H20 |
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2 |
H2SO4 H2O |
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3 |
NH4OH H2O |
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Distillation II:
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Before Distillation |
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Mass of
volumetric flask |
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Mass of
water-alcohol mixture |
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Mass of
volumetric flask with water-alcohol mixture |
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Volume of
water- alcohol mixture |
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Density of
water-alcohol mixture |
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% alcohol in
the mixture |
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After Distillation |
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Beaker |
Temp start/ Temp end (C) |
Mass of beaker (g) |
Mass of beaker + distillate (g) |
Volume of distillate (mL) |
Density of Distillate (g/mL) |
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1 |
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2 |
/ |
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3 |
/ |
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4 |
/ |
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5 |
/ |
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Distillation
III:
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Chemicals
Tested for |
Chemicals added |
TAP WATER Observations |
DISTILLED
WATER Observations |
Results |
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Test 1: |
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Test 2: |
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Test 3: |
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Test 4: |
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Analysis:
1. Plot a graph of the following data. Label
both axis and include a title. The points should be connected, and no
regression line. Print the graph so that it fills the entire page. This graph
will be used to interpolate data from Day 2 lab procedure. Determine the %
alcohol of water before the distillation and after the distillation in each
beaker. Attach your graph to the end of the lab report.
% Alcohol
(x-axis) Density (g/ml)
10 0.9804
20 0.9664
30 0.9507
40
0.9315
50
0.9099
60
0.8870
70
0.8634
80
0.8391
90
0.8136
100
0.7851
2. Describe the process of distillation.
This description should include how the process works, where it is used in the
real world and a diagram to help illustrate the explanation. At the end,
briefly describe how distillation was used in the day one and day two
procedures. You may use your textbook or online sites, reference any
information or diagrams used.
Questions:
1. What type of mixtures can you separate
using distillation?
2. What role does the Bunsen burner have in
the distillation process?
3. Could the solution be distilled without
the burner? Why or why not?
4. Why was temperatures recorded during the
distillation process?
5. As you completed a distillation, you
noticed a white crystalline film lining the inside of the round bottom flask.
What could this substance be? Why didn’t you notice it in the original
solution?
Conclusion:
In
your conclusion, make specific references to objective(s) and results. The conclusion should also include sources of
experimental error and suggestions for improvement that are thoughtful and well
written. Be concise!