Name: Class: Date: cp final review part 2 Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. Standard conditions when working with gases are defined as. a. 0 K and 101.3 kpa c. 0 C and 101.3 kpa b. 0 K and 1 kpa d. 0 C and 1 kpa 2. What happens to the average kinetic energy of the particles in a sample of matter as the temperature of the sample is increased? a. The average kinetic energy decreases. b. The average kinetic energy increases. c. The average kinetic energy does not change. d. The change in average kinetic energy cannot be determined. 3. The average kinetic energy of the particles of a substance. a. is not affected by the temperature of the substance b. increases as the temperature of the substance is lowered c. is directly proportional to the temperature of the substance d. is equal to the total energy absorbed by the substance 4. Which are the first particles to evaporate from a liquid? a. particles with the lowest kinetic energy b. particles with the highest kinetic energy c. particles below the surface of the liquid d. All particles evaporate at the same rate. 5. Why does a liquid's rate of evaporation increase when the liquid is heated? a. More molecules have enough energy to overcome the attractive forces holding them in the liquid. b. The average kinetic energy of the liquid decreases. c. The surface area of the liquid is reduced. d. The potential energy of the liquid increases. 6. Which of the following will evaporate the fastest? a. water at 0 C b. water at 20 C c. water at 40 C d. All samples will evaporate at the same rate. 7. The escape of molecules from the surface of a liquid is known as. a. condensation c. evaporation b. boiling d. sublimation 8. The direct change of a substance from a solid to a gas is called. a. evaporation c. condensation b. sublimation d. solidification 1
Name: 9. Which of the following is an example of a phase? a. pressure c. temperature b. water vapor d. triple point 10. If the volume of a container of gas is reduced, what will happen to the pressure inside the container? a. The pressure will increase. b. The pressure will not change. c. The pressure will decrease. d. The pressure depends on the type of gas. 11. The volume of a gas is doubled while the temperature is held constant. How does the gas pressure change? a. It is reduced by one half. b. It does not change. c. It is doubled. d. It varies depending on the type of gas. 12. How is the ideal gas law usually written? PV a. = R c. PV = nrt nt PV nrt b. = nr d. P = T V 13. A breathing mixture used by deep-sea divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 101.4 kpa if P He = 82.5 kpa and P C 2 = 0.4 kpa? a. 82.9 kpa c. 18.5 kpa b. 19.3 kpa d. 101.0 kpa 14. How does the surface tension of water compare with the surface tensions of most other liquids? a. It is lower. b. It is about the same. c. It is higher. d. It is higher when a surfactant is added. 15. What is the shape of the water molecule? a. linear c. trigonal planar b. tetrahedral d. bent 16. Which of the following is primarily responsible for holding water molecules together in the liquid state? a. dispersion forces c. ionic bonds b. hydrogen bonds d. polar covalent bonds 17. What is primarily responsible for the surface tension of water? a. dispersion forces c. ionic attractions b. hydrogen bonding d. covalent bonding 18. The fact that ice is less dense than water is related to the fact that. a. the molecular structure of ice is much less orderly than that of water b. the molecules of ice are held to each other by covalent bonding c. ice has a molecular structure in which water molecules are arranged randomly d. ice has a molecular structure that is an open framework held together by hydrogen bonds 2
Name: 19. What type of compound is always an electrolyte? a. polar covalent c. ionic b. nonpolar covalent d. network solid 20. An electric current can be conducted by. a. methane gas c. a salt solution b. a sugar solution d. rubbing alcohol 21. Which of the following usually makes a substance dissolve faster in a solvent? a. agitating the solution b. increasing the particle size of the solute c. lowering the temperature d. decreasing the number of particles 22. If a crystal added to an aqueous solution causes many particles to come out of the solution, the original solution was. a. unsaturated c. an emulsion b. saturated d. supersaturated 23. If the solubility of a particular solute is at 20 C, which of the following solution concentrations would represent a supersaturated aqueous solution of that solute? a. at 25 C c. 9g at 20 C b. at 15 C d. 11g at 20 C 24. What is the molarity of 200 ml of solution in which 2.0 moles of sodium bromide is dissolved? a. 2.0M c. 0.40M b. 10M d. 4.0M 25. A solute depresses the freezing point because the solute. a. is colder than the solvent b. disrupts crystal formation of the solvent c. tends to sink to the bottom of the solution d. has bigger molecules than the solvent 26. Given 1.00 mole of each of the following gases at STP, which gas would have the greatest volume? a. He c. S 3 b. 2 d. All would have the same volume. 27. Why does a catalyst cause a reaction to proceed faster? a. There are more collisions per second only. b. The collisions occur with greater energy only. c. The activation energy is lowered only. d. There are more collisions per second and the collisions are of greater energy. 3
Name: 28. What happens to a catalyst in a reaction? a. It is unchanged. c. It is incorporated into the reactants. b. It is incorporated into the products. d. It evaporates away. 29. A catalyst works by. a. lowering the activation energy barrier b. shifting the equilibrium position toward the products c. changing the temperature of the reactants d. changing the particle size of the reactants 30. What happens to a reaction at equilibrium when more reactant is added to the system? a. The reaction makes more products. c. The reaction is unchanged. b. The reaction makes more reactants. d. The answer cannot be determined. 31. Which physical state of nitrogen has the highest entropy? a. solid c. gas b. liquid d. vapor 32. The amount of disorder in a system is measured by its. a. activation energy c. equilibrium position b. entropy d. K eq 33. Which of the following is transferred due to a temperature difference? a. chemical energy c. electrical energy b. mechanical energy d. heat 34. A process that absorbs heat is a(n). a. endothermic process c. exothermic process b. polythermic process d. ectothermic process 35. The quantity of heat required to change the temperature of 1 g of a substance by 1 C is defined as. a. a joule c. a calorie b. specific heat d. density 36. What is the amount of heat required to raise the temperature of 200.0 g of aluminum by 10 C? (specific heat of aluminum = 0.21 cal g C ) a. 420 cal c. 42,000 cal b. 4200 cal d. 420,000 cal 37. During a phase change, the temperature of a substance. a. increases c. remains constant b. decreases d. may increase or decrease 38. If a balloon is heated, what happens to the volume of the air in the balloon if the pressure is constant? a. It increases. c. It decreases. b. It stays the same. d. The change cannot be predicted. 39. When an acid reacts with a base, what compounds are formed? a. a salt only c. metal oxides only b. water only d. a salt and water 4
Name: 40. What is transferred between a conjugate acid-base pair? a. an electron c. a hydroxide ion b. a proton d. a hydronium ion 41. What are the acid and conjugate acid in the following bronsted lowry acid/base reaction? CN + H 2 HCN + H a. CN, H 2 c. CN, H b. H 2, HCN d. H 2, H 42. Which of the following represents a Brønsted-Lowry conjugate acid-base pair? a. S 3 2 and S 2 c. H 3 and H 2 b. C 3 2 and C d. NH 4 and NH 3 43. What is the charge on the hydronium ion (H 3 )? a. 2 c. 0 b. 2 d. 1+ 44. If the hydrogen ion concentration of a solution is 10 10 M, is the solution acidic, alkaline, or neutral? a. acidic c. neutral b. alkaline d. The answer cannot be determined. 45. What is the best description for a solution with a hydroxide-ion concentration of 1 10 4 M? a. acidic c. neutral b. basic d. The answer cannot be determined. 46. What is ph? a. the negative logarithm of the hydrogen ion concentration b. the positive logarithm of the hydrogen ion concentration c. the negative logarithm of the hydroxide ion concentration d. the positive logarithm of the hydroxide ion concentration Short Answer 47. What is the percentage of water in the hydrate CoCl 2 6H 2? If you had a 30 gram sample of this hydrate, how much would the mass be AFTER heating to a constant weight? Essay 48. Explain the difference between exothermic and endothermic chemical reactions, drawing potential energy diagrams with products, reactants, and labeled. 5