1. Drill – 4/5/11 1. What is dilution? 2. How does the amount of solute change? 3. How does the amount of solvent change?

2. Solutions Chapter 12

3. Why do some things dissolve? “Like dissolves like.”  Nonpolar solvents dissolve Nonpolar solutes (non polar molecules).  Polar solvents dissolve Polar solutes (polar molecules / ionic compounds)

4. Remember… Nonpolar – has a neutral net charge. ex: all nonpolar covalent molecules Polar – particles have a positively and negatively charged side. ex: any ionic compound, polar covalent molecules

5. Solubility Values  The amount of substance required to form a saturated solution with a specific amount of solvent at a specified temperature  Grams of solute per grams of solvent

6. Effects of Pressure on Solubility  No effect on solids and liquids  Increase in pressure for gases = increase in solubility in liquids  Henry’s Law – The solubility of a gas is directly proportional to the pressure of that gas on the surface of liquid  Ex. Bottling soda

7. Solubility of Solids in Liquids  Effect of Temperature on Solid Solubility: increases solubility (usually) as temp. increases.

8. Solubility of Gases in Liquids  Effect of Temperature on Gas Solubility: Decreases solubility (usually) as temp. increases.

9.  Solubility Curve WS

10. Concentration A measure of the amount of solute in a given amount of solvent or solution. (General terms dilute and concentrated are general and difficult to transfer between different types of solutions.)

11. Molarity  The number of moles of solute in one liter of solution.  Molarity: Molar (M)  Molarity = amount of solute (mol) volume of solution (L) volume of solution (L)

12. Molality  The number of moles of solute per kilogram of solvent.  molality: molal ( m )  molality = amount of solute (mol) mass of solvent (kg) mass of solvent (kg)

13. Dilution with Molarity  M = mol/V can be rearranged to mol = M×V If we don’t change the amount of solute (which is the case with dilution) then moles before = moles after mol 1 = mol 2 M 1 V 1 = M 2 V 2