1. Starter S-160 Define A.Saturated solution B.Miscible C.Supersaturated solution

2. Solutions Chapter 16

3. 16.1 Properties of Solutions Chapter 16

4. Solutions occur when a solute dissolves in a solvent Solutions are homogeneous mixtures Three factors determine how rapidly solutes dissolve 16.1 Solution Properties Sink Hole Animation

5. 1.Stirring – moves fresh solvent over the surface of the solute 2.Temperature – particles move faster at higher temperatures, increase in frequency and force of collisions between solute and solvent 3.Particle Size – smaller particles expose greater surface areas to the colliding solvent 16.1 Solution Properties

6. Solubility – the amount of solute dissolved in a given amount of solvent Unsaturated – more solute can be dissolved at a specific temp Saturated – maximum solute that can be dissolved 16.1 Solution Properties

7. Some liquids are infinitely soluble in each other. They are said to be miscible. Immiscible – liquids that are insoluble in each other Solubility is often given as grams of solute per 100g of solvent 16.1 Solution Properties immiscible

8. A solubility curve gives the solubility (usually in grams solute per 100g solution) as it varies with temperature For most substances solubility increases with temperature Charts are for specific solvents You will need to read these charts for the test 16.1 Solution Properties

9. Pressure has little effect on the solubility of liquids or solids Strong effect on the solubility of gases Henry’s Law – at a certain temperature, the solubility of a gas in a liquid is proportional to the pressure of the gas above the liquid 16.1 Solution Properties

10. Starter S-162 Using the chart that will show up in a second, A.What is the solubility of sodium nitrate at 70 o C? B.How much Potassium Iodide could be dissolved in 400g of water at 10 o C? C.A saturated solution of NH3 is heated from 20 o C to 60 o C, how much ammonia precipitates out?

11. 16.2 Concentrations of Solutions Chapter 16

12. There are different ways to calculate how much solute is dissolved Concentration – the amount of solute dissolved in a solvent Dilute – small amount of solute Concentrated – large amount of solute 16.2 Concentrations of Solutions

13. Molarity (M) – the number of moles of solute dissolved in one liter of solution Moles are calculated from the mass Volume must be in liters (convert from mL if necessary) Volume is the total final volume of the solution, not the volume of the solvent 16.2 Concentrations of Solutions

14. Example: 0.90g NaCl is dissolved to make 100.0 mL of solution. What is the molarity of the soution? 16.2 Concentrations of Solutions

15. Example: Household laundry bleach is a dilute aqueous solution of sodium hypochlorite. How many moles of solute are present in 1.5 L of 0.70M NaClO? 16.2 Concentrations of Solutions

16. Often it is necessary to dilute a chemical. Make it’s molarity lower However, we can not reduce the number of moles in solution without a chemical reaction 16.2 Concentrations of Solutions

17. Example: How many milliliters of aqueous 2.00M Magnesium Sulfate must be diluted with water to prepare 100.0 mL of 0.400 M Mangesium Sulfate? This means that 20.0 mL of the 2.00 M solution must be mixed with 80.0 mL of water (the solvent) to make the 0.400 M solution 16.2 Concentrations of Solutions

18. Percent Solutions – can be expressed two ways Percent by mass 16.2 Concentrations of Solutions

19. Example: How many grams of glucose is needed to make 2000.0g of a 2.8% by mass solution? 16.2 Concentrations of Solutions

20. Percent by volume It helps often to remember that 1g of water equals 1 mL of water 16.2 Concentrations of Solutions

21. Example: What is the percent volume of ethanol (C 2 H 6 O) in the final solution when 85 mL of ethanol is diluted by adding 165 mL of water? 16.2 Concentrations of Solutions

22. Starter S-164 18.2 g of H 2 SO 4 are dissolved to make a 1.3 M solution. What is the final volume of the solution?

23. 16.3 Colligative Properties of Solutions Chapter 16

24. Colligative Property – depends only on the number of solute particles, not their identity 1.Vapor-Pressure Depression (lowering) 2.Boiling-Point Elevation (increasing) 3.Freezing-Point Depression 16.2 Concentrations of Solutions

25. Vapor-Pressure Depression The surface of a liquid has particles that are constantly leaving the surface and some particles returning (equilibrium) 16.2 Concentrations of Solutions

26. Vapor-Pressure Depression If a solute is dissolved in the solvent Not as many molecules can escape the surface 16.2 Concentrations of Solutions

27. Vapor-Pressure Depression This reduces the amount of gas above the solution So the vapor pressure decreases 16.2 Concentrations of Solutions

28. Vapor-Pressure Depression The decrease in a solution’s vapor pressure is proportional to the number of particles the solute makes in solution 16.2 Concentrations of Solutions

29. Freezing-Point Depression When a substance freezes the particles take on an orderly pattern The addition of a solute disrupts this pattern More kinetic energy must be withdrawn form the solution to cause it to solidify 16.2 Concentrations of Solutions

30. Freezing-Point Depression The difference in temperature between the normal freezing point of the solvent and the freezing point of the solution is called freezing-point depression 16.2 Concentrations of Solutions

31. Freezing-Point Depression Salt is added to ice to lower the freezing point If enough salt it added, the freezing point is depressed and the ice turns to liquid 16.2 Concentrations of Solutions

32. Boiling Point Elevation Boiling occurs when the vapor pressure of the liquid equals the atmospheric pressure Solutes decrease vapor pressure, so a solution must be at a higher temperature before it can boil 16.2 Concentrations of Solutions

33. Boiling Point Elevation The difference between the normal boiling point of the solvent and the boiling point of the solution is called boiling point elevation 16.2 Concentrations of Solutions

34. Remember that all colligative properties are proportional to the number of particles in solution The greatest effect would occur in a 50/50 solutions Antifreeze is mixed with water to increase the boiling point and to lower the freezing point 16.2 Concentrations of Solutions

35. Starter S-165 What is the percent by mass if 12.0 g of sodium chloride is dissolved in 52 mL of water? What is the percent by volume if 41 mL of sulfuric acid is dissolved in 202 mL of water?

36. Starter S-167 Test Day!