1. Unit 10 Review 2011

2. 1. Describe the following terms Solution Solvent Solute Soluble Insoluble Miscible Immiscible Homogeneous mixtures of 2 or more substances Dissolving medium Substance that dissolves Will dissolve Won’t dissolve Liquids are soluble in one another Liquids aren’t soluble in one another

3. 2. Examples of the solutions Solid in a liquid Gas in a liquid Solid in a solid Gas in a gas Salt water Carbonated beverage Steel/braces Air

4. 3 Describe what happens as a crystal of salt (NaCl) dissolves in water. Charged ends of water are attracted to the ions in salt This attraction is strong enough to pull the ions away

5. 4 How is the dissolving process different in sugar (compared with salt)? OH bonds attract H of H 2 O molecules until sucrose molecule is surrounded by many H 2 O molecules, which then pull entire sucrose molecule away

6. 5 Why doesn’t oil dissolve in water? Would oil dissolve in anything? Oil is nonpolar and water is polar. Oil would dissolve in a nonpolar solvent.

7. 6 What is solubility? Maximum amount of solute that will dissolve in a given amount of solvent at a specific temperature and pressure.

8. 7. How does temp affect solubility? For solids? For gases? –What else changes gas solubility? As temp increases, solubility increases As temp increases, solubility decreases pressure

9. 8 What three things can be done to increase the rate at which a solid dissolves? a.Agitate the mixture b.Increase surface area of solute c.Increase temperature of solvent

10. 9 Dissolving is a Physical or Chemical change. PHYSICAL

11. 10 How would you prepare a supersaturated sugar solution? Include the term “seed crystal”. Make a saturated solution at a high temperature. Then cool slowly so excess solute remains dissolved at a lower temp. when a seed crystal is added, the entire solution will crystalize.

12. 11 What is one test you could do to determine if a solution was saturated, unsaturated, or supersaturated? Describe how the results would be different for unsaturated, saturated, supersaturated solutions. Add more solute: unsaturated solution, it will dissolve saturated solution, it won’t dissolve supersaturated solution, a seed crystal will cause the solution to crystallize

13. 12 Water is known as the: Universal solvent

14. 13 What does solution concentration describe? Molarity: amount of solute dissolved in a given amount of solvent

15. 14 What do we use to describe solution concentration in chemistry? Molarity

16. 15 If a solution is “strong” it is If a solution is “weak” it is concentrated dilute

17. 16 What does it mean to dilute a solution? What equation do we use for dilutions? To lower its concentration “water it down” M 1 V 1 = M 2 V 2

18. 17 What is the molarity of a sodium chloride solution that contains 1.73 moles in 3.94 L of solution?

19. 18 What is the molarity of sodium hydroxide solution that contains 23.5 g NaOH in 500.0 mL of solution?

20. 19 How many grams of potassium nitrate are in 275 mL of 1.25 M solution?

21. 20 How many mL of 3.25 M hydrochloric acid would contain 16.0 grams of solute?

22. 21 You have 12.0 M HCl in your stock room, how would you prepare 600.0 mL of 2.50 M HCl solution? (12.0 M)(x) = (2.50 M)(600.0 mL) X=125 mL Measure out 125 mL of stock solution. Add 475 mL of distilled water.

23. 22 How would you correctly prepare 500.0 mL of a 3.0 M solution of NaOH from solid solute? NaOH Measure out 60 g of NaOH (s) Add water to the 500.0 mL line

24. 23 How would you prepare 500 mL of 3.0 M NaOH from 12.0 M concentrated stock solution? (12.0 M)(X) = (3.0 M)(500 mL) X=125 mL Measure out 125 mL of stock solution. Add it to 375 mL of distilled water

25. 26 An excess of zinc is added to 125 mL of 0.100 M HCl solution. What mass of zinc chloride is formed? Zn + 2HCl  ZnCl 2 + H 2

26. 27 When determining solubility remember: “like dissolves like”

27. 28 Polar/Nonpolar molecules will dissolve in water Polar

28. 29 Polar molecules: one of these shapes: Must have ______ bonds (electronegativity difference between 0.4- 2.1) Dumbbell, bent, trigonal pyramidal Polar covalent

29. 30 Molecules that won’t dissolve in water include anything with ____ bonds (electronegativity differences less than 0.4) Symmetrical shapes such as: These substances might dissolve in: nonpolar Linear, trigonal planar, tetrahedral Oil

30. 31 Determine whether or not the following chemicals will dissolve in water. Circle the ones that will MgCl 2 SeO 2 SiO 2 PCl 3 Ionic