P R A C T I C E T E S T

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1 South Pasadena onors hemistry Name Semester 2 inal Exam Period Date The following information may be helpful. P R A T I E T E S T D = m K = V M = n V P 1 V 1 P2 V2 T = P V = n R T 1 T R = L atm 2 mol K V c M c = V d M d Molar Mass = m n [ + ] [ ] = p + p = 14 p = log[ + ] p = log[ ] A =a b c rxn = qrxn n rxn [ + ] = 10 p [ ] = 10 p 1 atm = 760 mmg = 760 torr = 14.7 psi = kpa 1 mole = particles = 22.4 L gas at STP Solubility Rules for Salts Always soluble: alkali ions, N 4+, N 3, l 3, l 4, 2 3 2, 3 Generally soluble: l, Br, I Soluble except with Ag +, Pb 2+ 2+, g 2 Soluble except with Pb 2+, a 2+, Ba 2+, Sr 2+, Mg 2+ 2 S 4 Soluble except with Pb 2+, a 2+, Ba 2+, Sr 2+ Generally insoluble: 2, Insoluble except with a 2+, Ba 2+, Sr 2+ +, alkali ions, N 4 3 2, P 4 3, S 2, S 3 2, r 4 2, Insoluble except with alkali ions, N 4 + Strong Acids l, Br, I, N 3, 2S 4, l 3, l 4, I 4 Gases that orm 2S (g) 2 3 (aq) 2 (g) + 2 (l) 2S 3 (aq) S 2 (g) + 2 (l) N 4 (aq) N 3 (g) + 2 (l) Part 1: Multiple hoice. Select the answer choice that best completes the question. 1. Bonds between which of the following elements is expected to be most polar? (A) (B) N () P (D) S Br 4. An unknown element X forms a salt with the formula X 2. Which of the following could be X? (A) Al 3+ (B) a 2+ () Na + (D) Sn Which type of bond is described as a lattice of positive ions in a sea of electrons? (A) covalent (B) hydrogen () ionic (D) metallic 3. The compound (N 4) 2 3 contains how many atoms of hydrogen? (A) 2 (B) 4 () 6 (D) 8 5. Which of the following name is correctly paired with its formula? (A) arbonate 2 3 (B) hloride l 3 () erric e 2+ (D) Nitrate N 2 6. Which one of the following is the correct formula for calcium phosphate? (A) a 2(P 4) 3 (B) a 3(P 4) 2 () ap 4 (D) P 4a 3

2 7. What is the name of the compound N 2 3? (A) dinitride trioxide (B) dinitrogen trioxide () nitrate (D) nitrogen oxide 8. What is the percent of carbon in barium carbonate, Ba 3 (molar mass = g/mol)? (A) 3.04% (B) 6.09% () 14.0% (D) 20.0% 9. ow many moles of hydrogen cyanide, N, are contained in 9.00 grams of N? (molar mass = g/mol) (A) (B) () 1.00 (D) ow many molecules are in moles of carbon tetrachloride, l 4? (molar mass = 154 g/mol) (A) (B) () (D) Which of the following describes the bonds in a molecule of ethyne, 2 2? (A) 1 double bond, 2 single bonds. (B) 1 triple bond, 2 single bonds. () 2 double bonds, 1 single bond. (D) 3 single bonds. 12. The total number of dots drawn in the Lewis structure of nitrogen, N 2, is (A) 5 (B) 10 () 14 (D) Which of the following is the correct Lewis Structure for carbon monoxide,? (A) (B) () (D) 14. Which one of these molecules is polar? (A) (B) () (D) l l N l l l l 15. Which of the following is paired INRRETLY with the solid it forms? (A) Bronze Metallic solid (B) a Ionic solid () 2 Molecular solid (D) P 4 10 Network covalent solid 16. An unknown solid has a melting point of 400 and conducts electricity. Which of the following could be the solid? (A) Diamond, (B) Salt, Nal () Sugar, (D) Zinc, Zn 17. Which of the following is expected for a sample of solid P 4 10? (A) It is malleable. (B) It has a low melting point. () It conducts electricity when it is melted. (D) It is lustrous. 18. What intermolecular forces are present between molecules of l but not 2? (A) Dipole-dipole interactions (B) ydrogen bonding () Ionic bonds (D) London dispersion forces

3 19. Water molecules are attracted to each other with this type of intermolecular force. (A) ovalent bonding (B) Dipole-dipole interactions () ydrogen bonding (D) London dispersion forces 20. Which of the following is expected do have the highest melting point? (A) B 3 (B) 4 () 2 (D) N The general formula n 2n describes the molecular composition of the hydrocarbon family known as the (A) alkadienes (B) alkanes () alkenes (D) alkynes 24. Which of the following is the correct name for the following compound: (A) 1,1-dibromobutane (B) 1,1-dibromopropane () 2-bromopropane (D) 3,3-dibromopropane Br Br 25. Which of the following is an isomer of the compound below: (A) 22. ow many carbons make up the parent chain in the following molecule? (B) () (A) 4 (B) 5 () 6 (D) 7 (D) 23. The number of isomers of bromopropane, 3 7Br, is (A) 2 (B) 3 () 4 (D) Which functional group is found in the following compound? (A) Aldehyde (B) arboxylic Acid () Ether (D) Ketone

4 27. The structure of which compound is given below? (A) Grain alcohol (ethanol) (B) Isopropyl alcohol (2-propanol) () Nail polish remover (acetone, or propanone) (D) Vinegar (ethanoic acid) 28. Which set of coefficients balances the equation for the complete combustion of ethane, 2 6? 2 6 (g) + 2 (g) 2 (g) + 2 (l) (A) 1,3,2,3 (B) 1,6,2,6 () 2,6,4,5 (D) 2,7,4,6 29. When the equation for the combustion of propene, 3 6, is balanced with the lowest whole-number coefficients, what is the coefficient of oxygen, 2? (A) 6 (B) 9 () 12 (D) When an alcohol reacts with a carboxylic acid, which of the following is formed? (A) A ketone (B) An ester () An ether (D) Which of the following compounds is expected to be soluble in water? (A) as 4 (B) es () Pbl 2 (D) SrBr Which of the following represents the dissociation of ai 2 in solution? (A) ai 2 a + I 2 (B) ai 2 a I () ai 2 a 2+ + I 2 (D) ai 2 is insoluble so it does not dissociate. 33. ow many grams of sodium hydroxide pellets, Na, are required to prepare 50.0 ml of a M solution? [molar mass Na = 40.0 g/mol] (A) (B) 2.00 () 3.00 (D) List the following solutions prepared with the same solute in order of increasing concentration: I g solute in a 240 ml solution II g solute in a 120 ml solution III g solute in a 120 ml solution (A) I < II < III (B) II < I < III () II < III <I (D) III < II < I 35. A 100 ml sample of a solution with a concentration of 5.00 M is diluted to a new volume of 400 ml with distilled water. The new concentration will be (A) 1.25 M (B) 1.66 M () 15.0 M (D) 20.0 M 36. The acid l 3 is named: (A) hloric acid (B) ydrochloric acid () ydrogen chlorate (D) ydrogen chlorine trioxide 37. A solution tested with cabbage juice turns green. Which of the following could be its p? (A) 1 (B) 4 () 7 (D) A substance that turns cabbage juice blue and slightly lights up a light bulb is a: (A) strong acid (B) strong base () weak acid (D) weak base

5 39. Which chemical is the conjugate base in the reaction? N N (A) 2 (B) N 3 () N 4 + (D) 40. If a solution has [ ] = M, what is the p? (A) 3 (B) 7 () 11 (D) An acid was neutralized by the following reaction: Na + l Nal + 2 This reaction would be classified as (A) decomposition (B) double replacement () single replacement (D) synthesis 42. 3P 3 3P 4 + P 3 When the equation above is balanced, the coefficient for 3P 4 is: (A) 1 (B) 2 () 3 (D) When solutions of potassium sulfate and calcium bromide are combined, which of the following precipitates? (A) KBr (B) as () as 4 (D) There is no precipitate. 44. Which of the following are products when magnesium metal is placed in hydrochloric acid? (A) (B) + () Mg (D) Mgl Zn Zn e In the half reaction above: (A) Zn is oxidized because it is gaining electrons. (B) Zn is oxidized because it is losing electrons. () Zn is reduced because it is gaining electrons. (D) Zn is reduced because it is losing electrons. 46. The classic holiday demonstration, hemist s Tree, undergoes the reaction: u + 2 Ag + 2 Ag + u 2+ The copper, u, is electrons and being. (A) gaining, oxidized (B) gaining, reduced () losing, oxidized (D) losing, reduced 47. When we reacted AgN 3 and K 2r 4 to form Ag 2r 4 and KN 3, was oxidized. (A) chromate ion (B) nitrate ion () silver ion (D) nothing (it wasn t a redox reaction) 48. What mass of sulfur dioxide, S 2 (64.0 g/mol), is produced when 245 g of sulfuric acid, 2S 4 (98.0 g/mol) reacts completely with zinc metal according to the balanced equation below? Zn + 2 2S 4 ZnS 4 + S (A) 64.0 g (B) 80.0 g () 128 g (D) 160 g 49. At STP, how many liters of oxygen gas react with 4.00 moles of P 3 according to this equation? 4 P 3 (g) (g) 6 2 (l) + P 4 6 (s) (A) 32.0 (B) 89.6 () 134 (D) 146

6 50. ow many moles of es 2 are required to produce 64 grams of S 2 according to the balanced equation below? 4 es 2 (s) (g) 2 e 2 3 (s) + 8 S 2 (g) (A) 0.40 (B) 0.50 () 3.2 (D) Is the reaction below endothermic or exothermic? 3 N N 3 + N 2 f: (A) Endothermic (B) Exothermic () Neither endothermic nor exothermic (D) It cannot be determined 52. What is the value of rxn for the following reaction? a(s) + 2 a 3(s) f: (A) 2236 kj/mol (B) 178 kj/mol () +178 kj/mol (D) kj/mol 55. Which one of the following changes will result in a decreased rate of reaction? (A) adding a catalyst (B) heating up the reactants () cutting the reactants into smaller pieces (D) diluting the reactants 56. Photographic film is sometimes kept in the refrigerator (A) because cold film results in sharper pictures. (B) to slow down the chemical reactions on the film. () to protect the film from light. (D) because the cold insulates the film. 57. What distance corresponds to the activation energy for the reaction of X to Y? 53. onsider the following reaction: 2 + = 2 == The average bond energies in (kj/mol) are: 1070 = 745 = 495 What is the value of rxn? (A) 1145 kj/mol (B) 345 kj/mol () +345 kj/mol (D) kj/mol (A) a (B) b () c (D) d 58. What is the rxn for the reaction shown on the graph? 54. onsider the reaction: N + N N N The average N N bond energy is 160 kj/mol. What is the value of rxn? (A) 160 kj/mol (B) 0 kj/mol () +160 kj/mol (D) +320 kj/mol (A) 15 kcal/mol (B) 5 kcal/mol () +5 kcal/mol (D) +10 kcal/mol

7 Questions 59-60: Refer to the following kinetic energy graph. Lines A and B represent the average kinetic energy and the threshold energy, respectively. # 59. If the temperature of the system is increased, how will the graph change? (A) A will increase, while B remains the same. (B) B will increase, while A remains the same. () Both A and B will increase. (D) Both A and B will remain the same. 60. If B decreases while A increases, which of the following may have happened? I. The reaction mixture was heated. II. A catalyst was added. III. The surface area of the reaction mixture was increased. (A) I only. (B) II and III only. () I and II only. (D) I, II, and III. 61. onsider the reaction: 2 N(g) + 2(g) 2 N 2(g) At equilibrium, [N] = 0.10 M, [ 2] = 0.10 M, and [N 2] = M. This reaction is considered: (A) Reactant-favored (B) Product-favored () Neither reactant- nor product-favored (D) It cannot be determined 62. What is the expression for the equilibrium constant for the following reaction: 2 (g) + I 2 (s) 2 I (g) (A) [2][I2] [I] 2 (B) [I]2 [ 2][I 2] () [2] [I] 2 (D) [I]2 [ 2] A B KE 63. This reaction takes place in solution: A 2 B At equilibrium, [A] = 0.1 M and [B] = 0.1 M. What is the value of the equilibrium constant, K eq? (A) 0.10 (B) 0.20 () 1.0 (D) 10 Questions 64-68: The value of K eq for the following reaction is heat + 2S 3 (aq) 2 + (aq) + S 3 2 (aq) 64. Which of the following may indicate that equilibrium has been reached? I. [ 2S 3] = [ + ] = [S 3 2 ] II. Equal moles of + and S 3 2 have been added. III. The p remains constant. (A) II only. (B) III only. () I and III only. (D) I, II, and III. 65. Which of the following is the correct expression for the equilibrium constant, K eq, for the reaction? [ 2S 3] (A) [ + 2 ][S 3 ] [ 2S 3] (B) [ + ] 2 2 [S 3 ] () [+ ] 2 2 [S 3 ] [ 2S 3] (D) 2[+ 2 ][S 3 ] [ 2S 3] 66. In an equilibrium mixture, [ 2S 3] = M, and [S 3 2 ] = M. What is the [ + ] in this mixture? (A) M (B) M () M (D) M

8 67. To a mixture already at equilibrium, which of the following would have a greater concentration if 2S 3 (aq) were added? I. 2S 3 II. + III. S 3 2 (A) I only. (B) II only. () II and III only. (D) I, II, and III 68. Which of the following conditions would produce the highest [ 2S 3]? (A) p = 2.0 T = 10 (B) p = 2.0 T = 40 () p = 9.0 T = 10 (D) p = 9.0 T = onsider the reaction: 2 S 2(g) + 2(g) 2 S 3(g) + heat which of the following would shift the reaction to produce more S 2(g)? (A) Add 2 to the reaction mixture. (B) Increase the volume of the container. () Lowering the temperature. (D) Remove S 3(g) to the reaction mixture. 70. In the reaction heat + 2 Br(g) 2(g) + Br 2(l) Under which conditions would produce the most Br 2(l)? (A) igh temperature, low pressure (B) igh temperature, high pressure () Low temperature, low pressure (D) Low temperature, high pressure Answers D 3. D 4. D 5. A 6. B 7. A 8. B 9. A 10. D 11. B 12. B 13. B 14. B 15. D 16. D 17. B 18. A D A 24. A 25. A 26. D 27. A 28. D 29. B 30. B 31. D 32. B 33. A 34. A 35. A 36. A D 39. D B D 45. B D 48. B B 51. B 52. B 53. B 54. A 55. D 56. B 57. B 58. B 59. A A 62. D 63. A 64. B A 67. D 68. A 69. B 70. B

9 Part 2: ree Response. or each question, write your response in the space provided. If the problem requires mathematical computation, show your work (steps) neatly, reporting your answer with the correct number of significant digits and units. Partial credit is given only when the process taken is clearly shown. Place a box around or circle your final answer. Unit conversions should be shown using dimensional analysis, showing how all units cancel out. Work for problems involving formulas should follow the I.E.S.A. form. 1. A particular compound containing only chlorine and oxygen is 52.56% chlorine by mass. The molar mass of the compound is found to be between 60 and 70 g/mol. a. ind the empirical formula of the compound. (3 points) b. ind the molecular formula of the compound. (2 points) c. A L sample of this compound was obtained at STP. ow many molecules are in this sample? (3 points) 2. onsider the compounds and a. Draw the Lewis Structures for the following compounds. Then identify the type of solid formed, and the major inter-particle forces involved. (3 points) ompound: a Lewis Structures: Type of Solid ormed: Inter-Particle orces

10 3. omplete the chart for the following compounds: (5 points) ompound: BI 3 S 2 Lewis Structure Molecular Shape Bond Angles Molecule is Polar Non-Polar Polar Non-Polar Type of IM: 4. A refrigerant has a molecular formula a. Draw two possible structural formulas for 4 10 and name them. (4 points) b. Write the balanced equation for the combustion of (2 points) 5. Write the equation for the reaction between propene and chlorine gas using structural formulas. (2 points) 6. omplete the table for aqueous samples of each compound, predicting its color in cabbage juice and its conductivity with a light bulb, and writing its dissociation equation. (4 points) ompound abbage Juice olor [red green purple] onductivity [bright dim dark] Dissociation Equation (i) Br (ii) Mg() 2 (iii) N 3

11 7. Solutions of ammonium chloride and barium hydroxide are combined. Write the balanced molecular equation, complete and net ionic equations (be sure to identify spectator ions) (4 points) 8. Lead metal is placed in a solution of hydrochloric acid. (3 points) a. Balanced molecular equation: b. Balanced net ionic equation. c. Which element is oxidized? Which element is reduced? 9. onsider the compound isopropyl alcohol, or 2-propanol, 3 8 (l). a. Write the balanced equation for the combustion of 2-propanol. (1 point) b. What volume (in L) of 2 at STP can be produced if 4.05 g 3 8 is burned? (3 points) c. If 4.25 L of 2 was actually produced in (b) above, what was the percent yield of 2? (1 point) d. What is the rxn if 1025 kj of energy is released when 30.5 g 3 8 is burned? (2 points) e. The enthalpies of formation, f, of 2 (g) and 2 (l) are 394 kj/mol and 286 kj/mol, respectively. ind the f of 3 8. (2 points)

12 10. onsider the reaction: 2 (g) + l 2 (g) 2 l (g). At a particular temperature, K eq = 841. a. Write the equilibrium constant expression for this reaction. (1 point) b. Experiment #1: A reaction mixture is found to contain the following: [ 2] = M, [l 2] = M, [l] = 0.38 M In which direction will the reaction shift? Justify with calculations. (3 points) 11. onsider the reaction: 2 N (g) (g) N 2 (g) (g) Initially, 0.10 mol N, mol 2, and 0.10 mol 2 are placed in a 1.0 L container at 300 K. At equilibrium, [N] = M. a. What are concentrations of all substances at equilibrium? (3 points) b. What is the expression and value of K eq? (2 points)

Semester 2 Review U N I T 6 C O M P O U N D S U N I T 6 N A M I N G C O M P O U N D S. South Pasadena Chemistry Semester 2 Review Period Date

Semester 2 Review U N I T 6 C O M P O U N D S U N I T 6 N A M I N G C O M P O U N D S. South Pasadena Chemistry Semester 2 Review Period Date South Pasadena Chemistry Name Period Date U N I T 6 C O M P O U N D S Consider the compound Ba(NO 3) 2. Classify: [ Ionic Covalent Acid Organic ] Name the compound: barium nitrate Calculate the Molar Mass.