Review for the Final Exam (answers on the last page)

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1 Review for the Final Exam (answers on the last page) 1. Which response includes all of the following that involve chemical changes, and none that involve physical changes? I. souring of milk II. melting of silver III. digestion of food IV. burning of coal V. condensation of steam a. II and V b. I, III, and IV c. I, II, and III d. IV and V e. III, IV, and V. Which of the following are heterogeneous mixtures? I sugar II. sugar dissolved in water III. an aqueous suspension of magnesium hydroxide (milk of magnesia) IV. samples of nitrogen and oxygen in the same container V. samples of argon an iron in the same container a. III only b. I, II, and IV c. III and V d. III and IV e. II, IV and V 3. Which of the following numbers has 4 significant figures? a b c d e How many millimeters are there in 5 feet? a mm b mm c mm d mm e mm 5. Caffeine, a stimulant in coffee and some cola drinks, is 49.47% carbon, 5.19% H, 8.8% N, 16.48% O. What is the mass of carbon contained in 37.1 g of caffeine? a g b g c g d g e. 4.3 g 6. The specific gravity of ethyl chloride, an external painkiller, is 1.37 at 10C. What is the mass of 47.4 ml of the liquid? a g b g c g d. 5.5 g e g 7. Methane, CH 4, boils at 16C. What is the boiling point of methane in F? a. 58F b. 108F c. 60F d. 33F e. 464F 8. The specific heat of aluminum is J/gC. How many joules of heat are absorbed by 15.0 g of Al if it is heated from 0.0C to 60.0C? a. 540 J b. 70 J c. 81 J d..40 J e J 9. Each response below lists an ion by name and by chemical symbol or formula. Also each ion is classified as monatomic or polyatomic and as a cation or anion. Which response contains an error? 3 a. phosphate / PO 4 / polyatomic / anion b. sulfite / SO 3 / polyatomic / anion c. nitrite / NO 3 / polyatomic / anion d. iron(ii) / Fe + / monatomic / cation e. bromide / Br / monatomic / anion

2 10. From the following ionic compounds, choose the name / formula pair that is not correctly matched. a. sodium sulfide / Na S b. ammonium nitrate / NH 4NO 3 c. zinc hydroxide / Zn(OH) d. sodium sulfate / Na SO 3 e. calcium oxide / CaO 11. Calculate the mass of one bromine atom. a g b g c g d g e g 1. How many grams of CaCl equal 4.6 moles of CaCl? a. 6.1 g b. 170 g c. 30 g d. 473 g e. 3 g 13. Calculate the percent by mass of nitrogen in ammonium carbonate, (NH 4) CO 3. a. 17.5% b. 7.8% c. 9.% d. 35.0% e..86% 14. A 4.68-g sample of an oxide of iron was found to contain g of iron and 1.80 g of oxygen. What is simplest formula for this compound? a. FeO b. Fe O 3 c. Fe 3O 4 d. FeO e. Fe 3O 15. A compound contains, by mass, 87.5% nitrogen and 1.5% hydrogen. Its molecular weight is found to be 3 g/mol. What is its molecular formula? a. N H 6 b. N H 4 c. N H 5 d. NH 3 e. NH 16. What mass of hematite, Fe O 3, would contain 4.0 kg of iron? a kg b kg c kg d kg e kg 17. A chemical bottle containing K Cr O 7 is 98.7% pure. What mass of Cr is present in 350 g of this chemical? a. 118 g b. 10 g c. 1 g d. 14 g e. 16 g 18. Balancing a chemical equation so that it obeys the law of conservation of matter requires: a. Adjusting the coefficients in front of the formulas so there are the same number and type of atom on both sides of the equation. b. Making sure the reactants and products are in the same phase. c. Keeping the total charge the same on both sides of the equation. d. Changing the formulas of the products and reactants. e. Keeping the same number of molecules on both sides of the equation. 19. Balance the following equation with the smallest whole number coefficients. What is the coefficient for H O in the balanced equation? LiBF 4 + H O H 3BO 3 + HF + LiF a. 3 b. c. 5 d. 6 e How many moles of CaCO 3 would have to be decomposed to produce 19 grams of CaO? CaCO 3 CaO + CO a b c..00 d..5 e..30

3 1. How many grams of PI 3 could be produced from 50. g of I and excess phosphorus if the reaction gives a 98.5% yield? P 4 + 6I 4PI 3 a. 46 g b. 54 g c. 66 g d. 70 g e. 86 g. In the sequential reactions shown below, the first reaction has an 80% yield and the second reaction has a 60% yield. A + B C + D C + E F What is the yield of F? a. 60% b. 80% c. 0% d. 48% e. 70% 3. The density of a 7.50% solution of ammonium sulfate, (NH 4) SO 4, is 1.04 g/ml. What mass of water would be required to prepare 750. ml of this solution? a g b g c g d g e g 4. Calculate the molarity of the resulting solution if enough water is added to 50.0 ml of 4.0 M NaCl solution to make a solution with a volume of.80 L. a M b M c M d M e M 5. Give the number of protons, neutrons, and electrons of the 18 Te anion. a. 5 p; 76 n; 5 e b. 5 p; 18 n; 5 e c. 76 p; 5 n; 5 e d. 5 p; 18 n; 54 e e. 5 p; 76 n; 54 e 6. What is the symbol for a species composed of 35 protons, 44 neutrons, and 36 electrons? a. b. c. d. e. 7. What is the atomic weight of a hypothetical element consisting of two isotopes, one with mass = 64.3 amu (6.00%), and one with mass = 65.3 amu? a amu b amu c amu d amu e amu 8. What is the total number of electrons in the fifth energy level (n = 5). a. 16 b. 3 c. 5 d. 50 e What is the electron configuration of tin, Sn? a. [Kr]5s 3d 10 3f 14 5p 4 b. [Kr]5s 3d 10 4d 14 5p 4 c. [Kr]5s 3d 10 4f 14 5p d. [Kr]5s 4d 10 5p e. [Xe]5s 4d 10 5p 30. How many unpaired electrons are there in a neutral iodine atom (element 53)? a. one b. two c. three d. four e. five 31. What would be the outer electron configuration of alkaline earth metals? a. ns np b. np c. ns 0 np d. nd e. ns 3. Which element has the largest atomic radius? a. Al b. Si c. P d. S e. Cl

4 33. Which of these comparisons according to radius is (are) correct? I. Na + > Mg + II. In 3+ > Sr + III. Cl > K + IV. Cl > K a. I and II b. II and IV c. I and III d. II and III e. III and IV 34. Which element has the lowest electronegativity? a. K b. Ca c. Ga d. Ge e. As 35. Which pair of elements below would be least likely to form an ionic bond between them? a. Na / S b. C / N c. Al / F d. Mg / Br e. Cs / O 36. Which one of the following compounds is not a salt? a. LiI b. Al(ClO 4) 3 c. HI d. Fe(ClO 3) 3 e. NH 4Br 37. Which one of the following salts is insoluble in water? a. Na SO 4 b. K CO 3 c. Li 3PO 4 d. BaSO 4 e. (NH 4) 3AsO Which one of the following is a weak electrolyte? a. KBr b. H SO 4 c. H CO 3 d. NH 4ClO e. Ca(OH) 39. What is the total ionic equation for the following formula unit equation? BaCl (aq) + Na SO 4(aq) BaSO 4(s) + NaCl(aq) a. [Ba + (aq) + Cl (aq)] + [Na + (aq) + SO 4 (aq)] BaSO 4(s) + [Na + (aq) + Cl (aq)] b. [Ba + (aq) + Cl (aq)] + [Na + (aq) + SO 4 (aq)] BaSO 4(s) + [Na + (aq) + Cl (aq)] c. [Ba + (aq) + Cl (aq)] + [Na + (aq) + SO 4 (aq)] BaSO 4(s) + [Na + (aq) + Cl (aq)] d. [Ba + (aq) + Cl (aq)] + [Na + (aq) + SO 4 (aq)] BaSO 4(s) + [Na + (aq) + Cl (aq)] e. Ba + (aq) + SO 4 (aq) BaSO 4(s) 40. Determine the oxidation number of the underlined element in SO 3. a. + b. c. +3 d. +4 e Which of the following matched pairs of name and formula has an error? Formula / Name a. SeO / selenium dioxide b. XeF 6 / xenon hexaflouride c. N O / dinitrogen oxide d. Sb O 3 / antimony(iii) oxide e. S 4N 4 / tetrasulfur tetranitride 4. Which response includes all the following that are oxidation-reduction reactions, and no others? I. BaSO 3(s) BaO(s) + SO (g) II. K(s) + Br KBr(s) III. H CO 3(aq) + Ca(OH) (aq) CaCO 3(s) + H O IV. SnS (s) + 6HCl(aq) H SnCl 6(s) + H S(aq) V. 3Cl (g) + 6KOH(aq) 5KCl(aq) + KClO 3(aq) + 3H O a. II, III, and IV b. I and III c. II and V d. I and IV e. another one or another combination

5 43. Which of the following reactions is not a combination reaction? a. CO(g) + O (g) CO (g) b. PBr 3 + Br PBr 5(s) c. AgNO 3(aq) + HCl(aq) AgCl(s) + HNO 3(aq) d. Ca(s) + O (g) CaO(s) e. CO (g) + H O H CO 3(aq) 44. What is the formula for the binary compound of calcium and bromine? a. CaBr b. Ca Br c. CaB d. CaB e. CaBr 45. Which of the following is the correct Lewis dot formula for H S? a. b. c. d. e. 46. Draw the Lewis dot formula for NH 4+. How many unshared pairs of electrons are in the outer shell of the central nitrogen atom? a. b. 4 c. 6 d. 8 e What is the correct Lewis dot formula for H CO 3? a. b. c. d. e. 48. Assign a formal charge to each atom of a. As = 5+; Cl = 1b. As = 5; Cl = 7+ c. As = 0; Cl = 0 d. As = 3+; Cl = 1e. As = 6+; Cl = 49. Which response includes all the molecules below that violate the octet rule and only those? H O, SF 6, NF 3, BeCl a. H O and SF 6 b. SF 6, NF 3, and BeCl c. H O and NF 3 d. SF 6 e. SF 6 and BeCl 50. Which molecule exhibits resonance? a. BeI b. O 3 c. H S d. PCl 3 e. CO 51. Which response includes all of the following molecules that contain polar covalent bonds, and no others? NO, PCl 3, N, H O, P 4, NH 3 a. NO, P 4, and NH 3 b. PCl 3, N, and H O c. H O and NH 3 d. NO, PCl 3, and H O e. NO, PCl 3, H O, and NH 3

6 5. Draw the dot formula for the HNO molecule. The nitrogen atom is the central atom and the hydrogen atom is attached to an oxygen atom. On the basis of the number of regions of high electron density about the nitrogen atom, what is (are) the approximate bond angle(s) about the N atom? a. 180b. 90c. 10d. 10 and 90e Which one of the following molecules has sp hybridization at the central atom? a. BeF b. SeF 6 c. BF 3 d. PF 5 e. CF Which of the following statements about PBr 3 is false? a. It is a polar molecule. b. The PBr bonds are polar c. P is sp 3 hybridized. d. The bond angles are slightly larger than e. P has one lone pair. 55. Which response contains all of the following molecules that can be described as bent or angular molecules and none that have other shapes? BeI, SO, H S, PF 3, CO a. SO, H S b. BeI, SO c. BeI, PF 3, CO d. PF 3, CO e. another combination 56. Consider the SeF 4 molecule. Where is (are) the lone pair(s) located? a. In the axial position. b. In the equatorial position. c. In two octahedral positions at 180 angles from each other. d. In either axial or equatorial positions. e. There are no lone pairs present in SeF How many sigma ()bonds and how many pi () bonds does the ethene molecule contain? a. 4, b. 5, c. 5, 1 d. 5, 0 e. 8, 58. Ammonia, NH 3, is used to as fertilizer and as a refrigerant. What is the new pressure if 5.0 g of ammonia with a volume of 750 ml at 1.50 atm is expanded to 7.50 L at constant temperature? a. 15 atm b. 114 mm Hg c psi d atm e. 15 mm Hg 59. Calculate the volume occupied by g of NH 3 at STP, if it behaves ideally. a L b L c L d L e L 60. Calculate the density of O, in g/l, at STP. a g/l b g/l c. 1.6 g/l d g/l e g/l 61. At 150.C and 1.00 atm, 500. ml of a vapor has a mass of g. What is the molecular weight of the compound? a g/mol b g/mol c. 6.0 g/mol d g/mol e. 9.1 g/mol 6. A 10.0-L flask contains mole of H, mole of He and mole of Ne at 35.0C. What is the partial pressure of the Ne? a. 1.6 atm b atm c atm d atm e atm

7 Answer Section Review for the Final Exam MULTIPLE CHOICE 1. ANS: B PTS: 1 TOP: Chemical and Physical Changes. ANS: C PTS: 1 TOP: Mixtures, Substances, Compounds, and Elements 3. ANS: A PTS: 1 TOP: Use of Numbers 4. ANS: D PTS: 1 TOP: The Unit Factor Method (Dimensional Analysis) 5. ANS: A PTS: 1 TOP: Percentage 6. ANS: A PTS: 1 TOP: Density and Specific Gravity 7. ANS: C PTS: 1 TOP: Heat and Temperature 8. ANS: A PTS: 1 TOP: Heat Transfer and the Measurement of Heat 9. ANS: C PTS: 1 TOP: Ions and Ionic Compounds 10. ANS: D PTS: 1 TOP: Names and Formulas of Some Ionic Compounds 11. ANS: E PTS: 1 TOP: The Mole 1. ANS: D PTS: 1 TOP: Formula Weights, Molecular Weights, and Moles 13. ANS: C PTS: 1 TOP: Percent Composition and Formulas of Compounds 14. ANS: C PTS: 1 TOP: Derivation of Formulas from Elemental Composition 15. ANS: B PTS: 1 TOP: Determination of Molecular Formulas 16. ANS: A PTS: 1 TOP: Some Other Interpretations of Chemical Formulas 17. ANS: C PTS: 1 TOP: Purity of Samples 18. ANS: A PTS: 1 TOP: Chemical Equations 19. ANS: A PTS: 1 TOP: Chemical Equations 0. ANS: E PTS: 1 TOP: Calculations Based on Chemical Equations 1. ANS: C PTS: 1 TOP: Percent Yields from Chemical Reactions. ANS: D PTS: 1 TOP: Sequential Reactions 3. ANS: C PTS: 1 TOP: Concentrations of Solutions 4. ANS: E PTS: 1 TOP: Dilution of Solutions 5. ANS: E PTS: 1 TOP: Mass Number and Isotopes 6. ANS: E PTS: 1 TOP: Mass Number and Isotopes 7. ANS: D PTS: 1 TOP: The Atomic Weight Scale and Atomic Weights 8. ANS: D PTS: 1 TOP: Atomic Orbitals 9. ANS: D PTS: 1 TOP: Electron Configurations 30. ANS: A PTS: 1 TOP: Paramagnetism and Diamagnetism 31. ANS: E PTS: 1 TOP: More About the Periodic Table 3. ANS: A PTS: 1 TOP: Atomic Radii 33. ANS: C PTS: 1 TOP: Ionic Radii 34. ANS: A PTS: 1 TOP: Electronegativity 35. ANS: B PTS: 1 TOP: Electronegativity 36. ANS: C PTS: 1 TOP: Aqueous Solutions An Introduction 37. ANS: D PTS: 1 TOP: Aqueous Solutions An Introduction 38. ANS: C PTS: 1 TOP: Aqueous Solutions An Introduction 39. ANS: B PTS: 1 TOP: Reactions in Aqueous Solutions 40. ANS: D PTS: 1 TOP: Oxidation Numbers

8 41. ANS: B PTS: 1 TOP: Naming Binary Compounds 4. ANS: C PTS: 1 TOP: Oxidation-Reduction Reactions 43. ANS: C PTS: 1 TOP: Combination Reactions 44. ANS: E PTS: 1 TOP: Formation of Ionic Compounds 45. ANS: C PTS: 1 TOP: Lewis Formulas for Molecules and Polyatomic Ions 46. ANS: E PTS: 1 TOP: Writing Lewis Formulas: The Octet Rule 47. ANS: C PTS: 1 TOP: Writing Lewis Formulas: The Octet Rule 48. ANS: C PTS: 1 TOP: Formal Charge 49. ANS: E PTS: 1 TOP: Writing Lewis Formulas: Limitations of the Octet Rule for Lewis Formulas 50. ANS: B PTS: 1 TOP: Resonance 51. ANS: E PTS: 1 TOP: Polar and Nonpolar Covalent Bonds 5. ANS: C PTS: 1 TOP: Valence Bond (VB) Theory 53. ANS: A PTS: 1 TOP: Linear Electronic Geometry: AB Species 54. ANS: D PTS: 1 TOP: Tetrahedral Electronic Geometry: AB3U Species 55. ANS: A PTS: 1 TOP: Tetrahedral Electronic Geometry: ABU Species 56. ANS: B PTS: 1 TOP: Trigonal Bipyramidal Electronic Geometry: AB5, AB4U, AB3U, and ABU3 57. ANS: C PTS: 1 TOP: Compounds Containing Double or Triple Bonds 58. ANS: B PTS: 1 TOP: Boyle's Law: The Volume-Pressure Relationship 59. ANS: D PTS: 1 TOP: Avogadro's Law and the Standard Molar Volume 60. ANS: B PTS: 1 TOP: Avogadro's Law and the Standard Molar Volume 61. ANS: E PTS: 1 TOP: Determinations of Molecular Weights and Molecular Formulas of Gaseous Substances 6. ANS: A PTS: 1 TOP: Dalton's Law of Partial Pressures

9 (5 points each) Show work - Please write your complete work in space provided. Partial credit will be given. 1. The combination of coke and steam produces a mixture called coal gas, which can be used as a fuel or as a starting material for other reactions. If we assume coke can be represented by graphite, the equation for the production of coal gas is C (s) Determine the standard enthalpy change for this reaction from the following standard enthalpies of reaction : (1) () (3) C(s) CO(g) CH 4 (g) H O (g) H O (g) HO (g) H O (g) CH CO(g) 4 (g) CO 3 H H (g) (g) CO (g) (g) H (g) CO(g) H H H kj kj 06.1 kj ml 0f 0.0 M sulfuric acid solution to required to neutralize 30.0 ml of potaasium hydroxide solution. Write a complete balance equation for this reaction and calculate the molarity of the base. 3. For NO3 -, nitrate ion, draw the Lewis structure (by counting the valence electrons of each atom), determine the electron-domain geometry, the molecular geometry, resonances structures, hybridization, and show the angles between the bonds in a drawing. N is the central atoms, all other atoms are attached to N.

10 4. A metal crystallizes with a face-centered cubic lattice. The edge of the unit cell is 408 pm. Calculate the number of atoms in the unit cell and diameter of the metal atom. ( For FCC, edge; L = r 8 ) 5. Aluminum oxide forms when aluminum reacts with oxygen, 4 Al(s) + 3 O(g) AlO3(s) A mixture of 41.5 g of aluminum and g of oxygen is allowed to react. a) Identify the limiting reagent b) What mass of aluminum oxide can be formed? 6. Copper ( amu) has two isotopes: 63 Cu ( amu) and 65 Cu ( amu). What percent of copper atoms are 65 Cu?

11 Part II - Show-Work 1. H = double (1) + () + reverse (3) = (131.3 kj) + (-41. kj) + (-06.1) = kj. HSO4 + KOH KSO4 + HO namava () (10.0) (0.0) Mb = = = 0.13 M nbvb (1) (30.0) 3. : : O O N = O _ b. trigonal Planar c. trigonal Planar d. 3 resonance structures e. sp f. bond angle about 10 o A) a) Number of atoms in F.C.C. is: 8 x (1/8) + 6 x (1/) = 4 atoms. b) L = r 8 r = L / / 8 = pm diameter (d) = x r = x pm = 88.5 pm =.885 Angstrom (4x7) g (3x3) g (x10) g 4 Al + 3 O AlO3 8.4 g g X g (8.4) () (10) AlO3 from Al = = g = 156 g 4 x 7 b) 156 g AlO3 formed (117.65) () (10) AlO3 from O = = g 3 x 3 So, Al produce smaller amount of AlO3. Al is the limiting reagent.

12 amu = (1 - A) (6.9396) + (A) (64.978) A = Percent abundance of 65 Cu = 30.5%

1. Which response contains all the molecules below that violate the octet rule, and no others? SF 4, SiCl 4, H 2Te, AsF 5, BeI 2

Chem 1100 Pre-Test Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which response contains all the molecules below that violate the octet rule, and no