• How Do You Classify Mixtures?

Physical Mixing
A combination of substances in which no new substances are produced

Examples:
Saltwater, steel, air, dirt, blood,
Chicken soup, potting soil, oil and vinegar

• Based on the distribution of their components, mixtures can be classified as heterogeneous or homogeneous mixtures.

Heterogeneous Mixture
A mixture in which the composition is not uniform throughout

A heterogeneous mixture has two or more phases, making it obvious it is a mixture

Example:
Chicken soup, potting soil, oil & vinegar

Homogeneous Mixture, A.K.A. Solution
A mixture in which the composition is uniform throughout
Homogeneous mixtures are called solutions.

A homogeneous mixture has only one phase, so that it is not obvious it is a mixture.

Example:
Saltwater, steel, air

Solution
One substance, the solute, is dissolved in another, the solvent.

Solute
What is being dissolved

Solvent
What is doing the dissolving

Aqueous Solution
A solution in which water is the solvent

The Physical Separation of Mixtures

• Procedures to separate mixtures into their component substances without producing any new substances

Methods of Physical Separation:

Filtration
Separation of solids from liquids or separation of small particles from large particles by a semi-permeable membrane

Examples:
oil filters in cars, coffee filters in coffee makers

Distillation
Separation of substances based on the differences in their volatilities

Examples:
distillation of drinking water, distillation of liquor from fermented mixtures

Volatility
The ability and readiness of a liquid to be converted into vapor.
 

How do you classify mixtures?
 

Practice Problems Answer the following questions:

1. What is a mixture?

2. Does physical mixing of two substances produce a new substance?

3. Give an example of a mixture.

4. What is the difference between a heterogeneous mixture and a homogeneous mixture?

5. What is another word for a homogeneous mixture?

6. Give two examples of a heterogeneous mixture.

7. Give two examples of a homogeneous mixture.

8. Distinguish between a solute and a solvent.

9. Give an example of a solution.

10. What is an aqueous solution?

11. Why are milk and a just-opened Coca-Cola NOT examples of a solution?

12. What is a phase? a)  How many phases does a solution have? . b)  How many phases does a heterogeneous mixture have? . c)  How many phases does a just-opened Coca-Cola have?

13. Name and describe two methods for separating mixtures.

14. What is volatility?