1. Types of Mixtures

2. Heterogeneous mixtures
Homogeneous mixtures
Uniform composition throughout
Examples: salt water, sugar-water, metal alloys
Heterogeneous mixtures
NOT a uniform composition.
May be obvious to the naked eye, or must be viewed under a microscope
Examples: dirt, milk, bread

3. Types of Mixtures Solutions Suspensions Colloids
Homogeneous mixtures of two or more substances in a single phase. Small dissolved particles
Suspensions
Heterogeneous mixtures in with large dissolved particles.
Colloids
Heterogeneous mixtures with particles intermediate in size between solutions and suspensions

4. Solutions
A solution is formed when one substance dissolves in one another.
A substance which can dissolve is called soluble.
The solvent is the substance into which it dissolves.
When NaCl dissolves in water, the NaCl is the solute and the water is the solvent

5. Solutions
In a solution, the dissolved particles of the solute are so small that they can’t be seen.
The particles are the size of atoms, molecules, and ions.
The solute doesn’t settle out.
When the solution is poured through filter paper, the entire solution passes through.

6. Solutions
Solutions don’t have to be liquids. They can be any combination of solid/liquid/gas.
Air
Soda
Salt water
Metal alloy
Ethanol in water
Amalgam

7. Suspensions
In a suspension, the particles are so large that they settle out unless the mixture is constantly stirred or agitated.
Can be separated by pouring through a filter.

8. Colloids
Intermediate sized particles are dispersed throughout the dispersing medium.
The particles are small enough that they remain suspended in the solvent.
These mixtures can’t be separated by normal filtration.
Can be any combination of gas/liquid/solid

9. Types of colloids Sol Gel Liquid emulsion Foam Solid aerosol
Liquid aerosol
Solid emulsion

10. It is easy to determine if a mixture is a suspension – let it sit and if the particles settle out, it is a suspension.
The difference between colloids and solutions may be more difficult to determine.
The colloid particles may only be slightly larger than those of a solution, causing the mixture to appear homogeneous

11. Tyndall Effect
In a colloid, the particles are large enough that they will scatter light
If you shine a beam of light through a colloid, the light beam is visible due to the scattering of the light.
Shining a beam of light through a solution does not yield the same effect.

13. Electrolytes
A substance that dissolves in water and separates into ions in the solution is called an electrolyte.
The solution will conduct electricity
Examples: salt, hydrochloric acid, vinegar
A substance that dissolves in water and DOES NOT separate into ions (it remains as molecules) is a non-electrolyte
The solution will not conduct electricity
Examples: sugar, kerosene