1. Mixtures
Mixtures

2. Think of gravel and think of air. What are each of these made of?
Mixtures
What determines the properties of each mixture?
The properties depend upon properties of the materials in the mixture.
How many substances are there in a mixture?
A mixture must contain at least two substances.

3. What is a mixture?
A mixture is a physical combination of substances.

4. What is an example of a colloid? Smoke Mayonnaise Foam
What is a mixture called, that is like a suspension, but it has parts that do not settle?
A colloid
What is an example of a colloid?
Smoke
Mayonnaise
Foam

5. What are heterogeneous mixtures?
Heterogeneous mixtures are mixtures that have different parts that you can plainly see.
Think…Snack Mix…

6. Dust settles out of air onto furniture and shelves
Dust settles out of air onto furniture and shelves. What kind of mixture is dusty air? Why?
If you cannot see the individual dust particles, the dusty air is a suspension. It is cloudy, but the dust will settle over time. But if you see individual dust particles, the dusty air is just a heterogeneous mixture and not a suspension.

7. What do you think would happen if you mixed two suspensions?
The particles would eventually settle into layers, with one layer for each kind of substance in the two suspensions.

8. What does a mixture of sugar dissolved in water look like?
If you cannot see the sugar in water, how do you know sugar is dissolved in the water?
We dissolved the sugar in the water by stirring.
What is another name for a homogeneous mixture?
A solution
What is meant when we say that a mixture is homogeneous?
It is the same throughout.

9. What is a solution?
A solution is a mixture with parts that blend so that it looks the same everywhere, even under a microscope!

10. Solute The solute is the smaller amount dissolved in a solution.
When we mix sugar and water together, the sugar is the solute.
The solute is the material that dissolves and is the smaller portion in a solution.

11. Solvent
The solvent is the larger amount that dissolves the other substance in the solution.
When we mix sugar and water the water is the solvent. The water dissolves the sugar.

12. Alloy An alloy is a solution of a metal and another solid.
Two or metals are often bound together to form an alloy.

13. Solubility
The maximum amount of a solute that can dissolve in a solvent is called the solubility.
Solubility is the capacity to dissolve.
This can depend on temperature. Often the higher the temperature the more soluble a substance is.

14. Why might fish not get enough oxygen in hot water?
Oxygen gas does not dissolve readily in hot water.

15. How could you increase the amount of solute that will dissolve in a solvent?
Changing the temperature will often change the solubility of a substance. So, increasing the temperature will often increase the amount of solute that will dissolve in a solvent. For some substances, lowering the temperature would work instead. .

16. Separating Mixtures
Parts of mixtures can be separated using physical methods.
The different properties of matter are helpful in separating mixtures:
Density
Solubility
Particle size
Magnetism
Boiling point

17. How could you separate a mixture that consists of iron filings, sand, and salt?
You would use a magnet to separate the iron from the mixture. You could add water to the sand and salt. The salt will dissolve in the water. After it dissolves, you could pour the water through a filter. The sand will not pass through the filter. Then you could allow the water to evaporate and the salt would be left behind.

18. You need to separate a mixture of several kinds of dried beans
You need to separate a mixture of several kinds of dried beans. How could you accomplish this?
If the beans are different sizes, you could separate them by using sieves of various sizes. Otherwise, you would probably have to manually separate them by inspection. .

19. What is distillation?
Distillation separates the parts of a mixture by vaporization and condensation.

20. Two liquids boil at about the same temperature
Two liquids boil at about the same temperature. Would it be easy to separate them by distillation? Why or why not?
No, distillation uses vaporization and condensation to separate a liquid mixture. Two liquids with a similar boiling point would likely evaporate and condense at about the same time, making them hard to separate.

21. Saudi Arabia has a large number of distillation plants
Saudi Arabia has a large number of distillation plants. Why do you think they are so important there?
Saudi Arabia has little freshwater in the desert, so people must distill salt water into freshwater. Additionally, they use a type of distillation in their oil refineries.