1. Acids, Bases, and Solutions Chapter 7 Mrs. Jenkins

2. What is a solution, solvent, and solute? What is a solution? A well-mixed mixture that contains a solvent and at least one solute Ex. Tap Water, Ocean Water, Soda Water What is a solvent? The part of the solution present in the largest amount It dissolves the other substances Ex. Liquid in Tap Water What is a solute? The substance that is present in a solution is a smaller amount and is dissolved by the solvent

3. Colloids and Suspensions Colloids and Suspensions are mixtures that have different properties than solutions. What is a colloid? small, undissolved particles that do not settle out Is a mixture containing small, undissolved particles that do not settle out A colloid contains larger particles than a solution Ex. Fog, milk, mayonnaise, shaving cream

4. Colloids and Suspensions What is a suspension? small, undissolved particles that do not settle out Is a mixture containing small, undissolved particles that do not settle out Have you ever noticed that pepper and water do not mix completely? This is an example of a “suspension.” A suspension is a mixture in which particles can be seen and easily separated by settling or filtration. It contains particles that are even larger than solutions or colloids.

5. Solutions and Conductivity How would you know if a solution can conduct electricity or not? A solution of ionic compounds in water conducts electricity, but a water solution of molecular compounds may not. If no ions are present ( as is a sugar solution) electricity will not flow.

6. Effects of Solutes on Solvents The freezing point of water is 0 degrees and the boiling point is 100 degrees. When you add a solute to the solution it will LOWER the freezing point and RAISE the boiling point of a solvent. When you have water freezing at 0 degrees C to form crystals of solid ice, it is a lot harder to freeze at 0 degrees if you add salt to that water. You LOWER the freezing point below 0 degrees for the solution to freeze.

7. Effects of Solutes on Solvents Solutes raise the boiling point of a solvent In a liquid, molecules are moving close to each other, but in a gas they are far apart and are moving more rapidly. As the temperature of a liquid rises, the molecules gain energy and escape into the air. Question: Does salt water have a lower or high freezing point than pure water?

8. Concentration and Solubility What is a concentrated solution? One that as a lot of solute dissolved in the same amount of solvent Ex. Syrup What is a dilute solution? A Mixture that has only a little solute dissolved in a certain amount of solvent Ex. Sap of a Maple Tree

9. Changing and Measuring Concentration How do you change the amount of concentration? By adding more solute or by adding or removing solvent Ex. When you make juice which is a concentrated solution, you add water to make it more diluted To measure the amount of concentrated, you compare the amount of solute to the amount of solvent

10. Solubility What is solubility? Solubility is the amount of solute that can dissolve in a solvent at a given temperature. When it is a saturated solution, that means you have added so much solute that no more will dissolve. When it is supersaturated, you have more solute than you do solvent to dissolve. When it is unsaturated, is when you can still dissolve the solute.

11. Factors that affect Solubility What are the three factors that affect the solubility of a substance? Pressure, type of solvent, and temperature What happens when you increase the pressure of a substance? The higher the pressure, the more dissolved

12. Factors that affect Solubility How is the solubility affected by the type of solvent? “Like dissolves like”….so ionic and polar molecules dissolve well in polar solvents. What happens when you increase the temperature? For most solids, solubility increase with an increase in temperature. Gases become less soluble when you increase the temperature. Why does warm soda taste flat? It contains less gas.