Name:____________________ Period:_____
Partner(s):__________________________ Lab Station:_____
Separation of a Mixture
Procedure:
Part A: Observing Physical Properties
1. Using a spatula, transfer a pea-sized amount each of salt, sand, and iron filings to three plastic
weighing dishes.
2. Observe the physical appearance of each substance and record your observations in Data
Table A.
3. Use a magnet in a Ziploc bag to move through each substance in the dishes. If the substance
is magnetic it will still to the bag and if a substance is not magnetic, nothing will happen.
Record your observations in Data Table A.
4. To remove the magnetic material, carefully open the bag and remove the magnet. The
magnetic material will fall off the bag and back into the weighing dish when the magnet is
removed.
5. To determine whether each substance is soluble in water, fill three small test tubes half-full of
tap water. Put a small amount of each substance into different test tubes. Gently shake the test
tube and record your observations in Data Table A.
6. Empty the test tubes into the designated waste beaker and rinse the test tubes out in the sink.
7. Pour the remaining sand into the salt sample. Mix together and make observations about the
physical appearance of the combination in Data Table A.
8. Transfer the sand-salt mixture to a 50-mL beaker and add about 10 mL of water. Stir the
sample with a stirring rod and record any changes that occur.
9. Clamp a ring to a ring stand to support a filter funnel. Position the funnel directly above the
beaker. Fold a piece of filter paper into quarters and place the paper in the funnel with three
quarters placed to one side so that the paper forms a cone.
10. Wet the filter paper slightly with distilled water from a wash bottle and then slowly pour the
mixture from step 8 into the funnel.
11. Using a wash bottle, rinse all of the solid remaining in the 50-mL beaker into the funnel. Use no
more than 5 mL of water.
12. After all the liquid has passed through the funnel, gently remove the filter paper and dispose of
it in the trash.
13. To clean up Part A, dump any remaining solids in the trash can and pour any liquids without
solid in them down the drain. Rinse all test tubes and beakers out before answering the
following questions. Move on to Part B when all of the questions have been answered.
Questions:
1. One substance is an element, one is a compound, and one is a mixture. Identify which
substance falls into which category.
2. Is the combination of salt and sand a new compound or a mixture? Explain.
3. Describe the results of the filtration experiment. Which substance remained on the filter paper
after filtration? What substance(s) passed through the filter paper?
Part B: Separation of a Mixture
14. Design a flow chart to indicate how a mixture of salt, sand, and iron filings can be separated
and the exact steps that need to be taken to obtain the data you need. (Hint: there should be
three separation steps and three mass determinations after the initial sample mass
determination.) Get the flow chart checked off before you start Part B.
15. Label your 50-mL beakers #1 and #2, weigh them both, and record the masses in Data Table
B. Transfer about 2 g of the unknown mixture into your pre-weighed beaker #1 and measure
the total mass of the mixture and container. Determine the mass of the mixture. Record all
data in Data Table B.
16. Use your flow chart to separate the mixture. Be sure to weigh all weighing dishes and filter
paper before adding any samples to them so you can find out how much each component of
the mixture weighs. (Hint: use beaker #2 to catch the saltwater mixture after the filtration.)
17. Determine the mass of salt, sand, and iron in the sample mixture. Remember to record all
data.
Data Table A: Observing Physical Properties
Substance
Physical Appearance
Salt
Sand
Iron
Physical Appearance
Sand + Salt
Data Table B: Separation of a Mixture
Mass of Original
Mass of Iron
Mixture
(recovered)
Magnetic?
Soluble in Water?
Effect of Water
Results of Filtration
Mass of Salt
(recovered)
Mass of Sand
(recovered)
Total Mass of
Recovered Solids
Questions:
4. What are the properties of salt, sand, and iron filings that allow you to separate the mixture?
5. Calculate the mass percentage of each component in the mixture. Assume that the total mass
is the original mass of the mixture that you tested.
6. The actual yield is the mass of material recovered after a separation process. The theoretical
yield is the maximum amount of substance that can be obtained, assuming 100% efficiency of
each step in the separation procedure. The actual yield is usually less than theoretical because
some material is generally lost in any physical manipulation in the lab. The percent yield, which
describes the efficiency of the recovery operation, is calculated using the following equation.
Calculate the percent yield for the separation of your mixture.
percent yield = (actual yield/theoretical yield) x 100%