Distillation of Salt Water Lab
Background:
Distillation consists of heating a liquid until it vaporizes, and then condensing the vapor and collecting it in a
separate container. Distillation is used to purify liquids, or to separate mixtures of liquids that have different
boiling points. There are many types of distillation, each of which has a distinct purpose. For this experiment
you will do a simple distillation in order to obtain pure water from salt water.
Water evaporates from the ocean, condenses and falls as precipitation in a process referred to as the water cycle.
Water from the land runs into the ocean. As it flows, water collects minerals and salts from the Earth’s crust.
When the water evaporates again, the salts and minerals are left behind.
Objective: Make fresh water from salt water by using the process of distillation.
Specific objectives: When you complete this lab, you should be able to demonstrate your knowledge of the
following skills and concepts:
1. Set up and use a distillation apparatus.
2. Measure the volume of a liquid.
3. Monitor and record observations during the distillation process.
4. Use your observations to compare the distillation process to the water cycle.
5. Explain how salts are involved in the water cycle.
Problem: What will be produced as salt water is continually heated?
Hypothesis: _______________________________________________________________________________
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Procedure: In your own words summarize how you did this lab. Include a Diagram of your distillation
apparatus with labels:
Data: Each minute from start to finish, record your observations of the salt water flask, glass bends and
tubing, and collection test tube. Be sure to note any changes observed.
Time
Saltwater container
(minutes)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Glass or tubing or
connectors
Collection beaker or test tube
Salt is also known as sodium chloride. The presence of chloride ion in solution is indicated by formation of the
white precipitate AgCl when silver nitrate solution is exposed to it. Prepare a small test tube to see how well
you have separated the salt from the water by adding 2 ml of your distillate. Take these to Mrs. Wiley. I will
have a sample of the Original Saltwater in a test tube and a sample of Distilled Water in another test tube. I will
add 5 drops of Silver nitrate solution to each tube. Relative concentrations are indicated by the amount of
precipitate formed. (A precipitate is a solid that forms in a chemical reaction.) Record your observations and
compare:
Original Saltwater test tube: __________________________________________________________________
Your Distillate test tube: ____________________________________________________________________
Distilled Water test tube: ____________________________________________________________________
Conclusion: (1)State if your hypothesis was supported or negated by the data in this lab and (2) what you found
out to be the true results. (3)List any errors that you made. (4)List any improvements you would make if you
did this experiment again.
Conclusion Questions:
1. Why does the liquid in the flask become a gas? _________________________________________________
2. What is this process called? ____________________________________
3. What part of the water cycle does this represent? ________________________________________________
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4. Where did the liquid you collected come from? _________________________________________________
5. What is this process called? ______________________________________
6. Would the liquid in the test tube be safe to drink? Explain your answer. _____________________________
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7. Explain why the salts should not evaporate with the water. ________________________________________
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8. If you were trapped on an island without water, explain how you could use what you learned to make ocean
water drinkable. (Be specific in your answer and your design.) _______________________________________
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9. What is an element? _______________________________________________________________________
10. What is a mixture? _______________________________________________________________________
11. How does a mixture differ from a compound? ________________________________________________
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12. What is meant by boiling point? ___________________________________________________________
13. What is the boiling point of water? _______________________
14. What is distillation? ____________________________________________________________________
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15. Why are we or why should we be concerned about changing sea water into regular drinking water?
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