Name:______

Mixture Separation Lab

Objectives: Observe the chemical and physical properties of a mixture.

  • Relate knowledge of chemical and physical properties to the task of purifying the mixture.
  • Analyze the success of methods of purifying the mixture.

Background: The ability to separate and recover pure substances from mixtures is extremely important in scientific research and industry. Chemists need to work with pure substances, but naturally, occurring materials are seldom pure. Often, differences in the physical properties of the components in a mixture provide the means for separating them. In this experiment, you will have an opportunity to design, develop, and implement your own procedure for separating a mixture. The mixture you will work with contains salt, sand, iron filings, and poppy seeds. All four substances are in dry, granular form.

Safety: Wear goggles. Use care when working with glassware.

PreLab Questions: In the blank write if the following properties are extensive or intensive:

______1. Iron is magnetic

______2. Water is a liquid at room temperature

______3. The density of water is 1.0g/mL

______4. A sample of water has a mass of 5.5 grams

______5. Hydrochloric acid will react with magnesium

______6. The volume of a piece of metal is 6.7cm3

______7. The length of a piece of string is 10.5cm

In the blank write if the following are chemical or physical properties of matter:

______8. color

______9. smell

______10. freezing point

______11. boiling point

______12. melting point

______13. attraction (paramagnetic) or repulsion (diamagnetic) to magnets

______14. viscosity

______15. density

______16. heat of combustion

______17. reactivity with water

______18. pH

Procedures:

  1. Obtain separate samples of each of the four mixture components from your teacher. Use the equipment you have available to make observations of the components and determine their properties. Look for things like whether the substance is magnetic, whether it dissolves, or whether it floats. Record your observations in your data table.
  2. Make a plan for what you will do to separate a mixture that includes the four components from step 1. Record your plan below and review it with your teacher.
  1. Obtain a sample of the mixture from your teacher. Using the equipment you have available, run the procedure you have developed.
  2. When you separated all four components inform your teacher.
  3. Clean your lab station. Draw a picture of a Bunsen burner next to your name.

Data:

Properties / Sand / Iron Filings / Salt / Poppy Seeds
Dissolves in Water
Floats in Water
Magnetic
Other

Conclusion Questions:

______1. On a scale of 1 to 10, how successful were you in separating and recovering each of the four components: sand, salt, iron filings, and poppy seeds? Consider 1 to be the best and 10 to be the worst. Justify your rating:

2. How did you decide on the order of your procedural steps? Would any order have worked?

3. If you could do the lab over again, what would you do differently? Be specific.

______&______4. Name two materials or tools that were not available that might have made your separation easier.

5. For each of the four components, describe a specific physical property that enabled you to separate the component from the rest of the mixture.

  • sand______
  • salt______
  • iron filings______
  • poppy seeds______

6. How could you separate each of the following two-part mixtures?

  • Lead filings and iron filings______
  • Sand and gravel______
  • Sand and finely ground polystyrene foam______
  • Salt and sugar______
  • Alcohol and water______

7. Classify each of the following as either a pure substance or a mixture.

______salt water

______carbon dioxide

______air

______mercury

______wood

______glass