1. Mixtures and Solutions Water unit B.3

2. Pure substances • Have a chemical formula or chemical symbol • Examples: • Elements (Lithium = Li) • Compounds (water = H2O)

3. Mixture • When 2 or more substances combine but substances retain their individual properties • Example – trailmix • Two classifications of mixtures: • Heterogeneous – mixture that is not uniform throughout • Example – salt and pepper • Homogeneous – mixture that is uniform throughout • Example – salt water

4. Solution • A special type of homogeneous mixture is a solution. • Solution – a homogeneous mixture of 2 or more substances (uniform or the same through out) • Example – salt water

5. Solute and Solvent • Solute – substance that is dissolved into another substance – usually less of this substance • Solvent – substance that does the dissolving – usually the greater amount • Your turn: • We create a solution by mixing copper –sulfate in water. • What part is the solvent? • What part is the solute?

6. colloid • A mixture containing solid particles small enough to remain suspended and not settle out • Example - milk

7. Suspension • A mixture containing large dispersed solid particles that are large enough to settle out or be separated by filtration • Example – muddy water

8. Tyndall Effect • Scattering of light beam caused by the reflection from suspended particles • If the beam scatters it is positive • If a mixture does not settle but exhibits the Tyndall effect then it is a ……… • Colloid • If a mixture does settle out, then it is a …….. • Suspension • If you cannot see a beam of light through a mixture, then the mixture is a …. • solution