1. “Everything around us is made up of chemicals, including ourselves
“Everything around us is made up of chemicals, including ourselves. Some things are made up of a single chemical, or substance. Orange juice, however, contains different kinds of molecules and is a mixture of substances. Vinegar is a solution with water acting as a solvent in which the other substances are dissolved. These substances can be separated physically from one another. Most foods are mixtures. Salad dressing is a mixture, called an emulsion, containing oil and vinegar. They do not mix properly, but separate out into the lighter oily layer and the heavier water layer containing the vinegar. Other kinds of mixtures may be solids, like coins, or gases, like the air around us. Toothpaste is a mixture called a suspension, in which fine particles are suspended in a liquid, and they do not dissolve. It is often necessary for chemist to separate out the different chemicals to find out what they are.”
Eyewitness Science “Chemistry” , Dr. Ann Newmark, DK Publishing, Inc., 1993, pg 14
Solutions

2. Types of Mixtures
Heterogeneous mixture-not uniform throughout; particles are large enough to see under a microscope; layers form
Suspension-the particles do not remain mixed unless the mixture is constantly stirred or agitated
Example: liquid medications

3. Types of Mixtures
Colloid-particles that are bigger than the particles in a solution but smaller than the particles in a suspension; can be noticed under a microscope.
Example: Milk

4. Types of Mixtures
Homogeneous mixture-uniform throughout; can’t distinguish between the types of particles; no layers form.

5. Definitions
Solution – a homogeneous mixture of two or more substances in a single phase
Solute - substance being dissolved
Solvent –substance doing the dissolving; present in greater amount

6. Classes of Solutions
aqueous solution:
solvent = water
water = “the universal solvent”
amalgam:
solvent = mercury
Ex:
dental amalgam
tincture:
solvent = alcohol
Ex:
tincture of iodine (for cuts)
organic solution:
solvent
contains ________
carbon
Ex: benzene, toluene, hexane

7. Types of Solutions Gaseous solutions
Ex: air
Solid solutions-one solid is mixed with another solid and is called an alloy
Ex: brass-a mixture of copper and zinc

8. Solvation
Electrolyte-A substance that dissolves in water to give a solution that conducts electricity
Example: salt water solution (presence of Na+ and Cl- ions) - +
salt

9. Solvation
Nonelectrolyte-A substance that dissolves in water to give a solution that does not conduct electricity.
Example: sugar solution (no ions in solution) - +
sugar

10. Making Solutions
In order for the solute to dissolve, the solvent particles must come into contact with the solute; fits into the intermolecular spaces of the solvent

11. Factors Affecting the Rate of Solution
1. temperature
As temp. , rate
As SA ,
rate
2. surface area
3. mixing
With more mixing,
rate
We can’t control
this factor.
4. nature of solvent or solute

12. Factors Affecting Rate of Solubility
Temperature-the particles move around quicker and can interact with each other more frequently
Surface area-as more particles are exposed on the surface, they can interact with each other more
Mixing-stirring helps to disperse the particles with each other