1. Solutions and Other Mixtures
CHAPTER 6.1
Solutions and Other Mixtures

2. Classifying Matter
Matter
The composition of a material can be used to classify it as a mixture or a substance
The composition of a pure substance is constant
The composition of a mixture can vary widely
Mixture
Substance
Element
Compound
Homogeneous
Heterogeneous

3. Types of Mixtures
Heterogeneous Mixture: The parts of the mixture are noticeably different from one another.
Examples: Sand, Salsa, Chocolate Chip Cookie Dough
Homogeneous Mixture: The substances are so evenly distributed that it is difficult to distinguish one substance in the mixture from another.
Examples: Swimming pool water, Stainless steel fork

4. Solutions, Suspensions, & Colloids
Mixtures can be classified based on the size of their largest particles.

6. Suspension Suspension –
Settles out or separates into different layers when it is no longer agitated
(no longer moving).
Heterogeneous mixture
Separates into layers over time
Particles can be trapped by filter paper (like a coffee filter)
Are cloudy in appearance
Examples: Sand and Water

7. Filtration Separates materials based on the size of their particles
Examples:
Drip coffee makers
Wire screens at an archaeological site

8. Colloid particles are larger than the particles in a solution.
No, you don’t need to learn the exact sizes of the particles, just realize that there is a defined size.

9. Colloids
Contain some particles that are intermediate in size and are in between the small parts in a solution, and the larger particles in a suspension.
They do not separate in layers
You can’t use a filter to separate the parts of a colloid
The scattering of light property can be used to separate them from other mixtures

10. Colloids Particles are large enough to scatter light.
That means that you actually see what we call a “beam of light” – in a solution, which has really small particles, the light passes right through.

12. Scattering of light

14. Slide #13 gives “opal” as an example of a colloid
Slide #13 gives “opal” as an example of a colloid. It’s a gemstone, and here’s what it looks like.

15. Emulsions
Liquid/liquid systems of 2 immiscible substances are called emulsion. Substances or particle size = microns.
Examples: butter (w/o), margarine (w/o), mayonnaise (o/w), salad dressing (o/w), milk (o/w), cream (o/w), and chip-dip (o/w).
Oil
Oil
Oil
H O
H O 2
Oil 2
Oil
Oil
Oil
H O
H O 2
Oil 2
Oil
Oil
Water
Oil
Oil/Water
Water/Oil

16. Solutions
Formed when substances dissolve and form a homogeneous mixture
Characteristics
Do not separate into distinct layers over time
Will not leave trapped substances when poured through a filter
Most are translucent (clear or see-through)

17. Solutions Solute Substance that dissolves in the solution.
Solvent
Substance that dissolves the solute,
stuff “doing the dissolving.”
Water in salt and water
water in “sweet tea”
What you have the most of!
Solute
Substance that dissolves in the solution.
Salt in the water
Sugar in the tea
Chemicals put in your fish tank.

18. Using Properties to Separate Mixtures
Distillation & Filtration
are 2 common separation methods