An Incomplete Study Guide For The First Semester Exam

An Incomplete Study Guide For The First Semester Exam Dr Mandes 1. 2. Which term refers to the number of protons in an atom? a. atomic mass b. atomic number c. isotopic mass d. proton number A cation is an atom that has. a. gained electrons b. gained protons c. a net positive charge d. a net negative charge 3. How many significant figures are in the number 0.0006042? a. 3 b. 4 c. 7 d. 8 4. Consider the numbers: 23.68 and 4.12. When added, the sum of these numbers has significant figures, and when multiplied the product of these numbers has significant figures? a. 3, 3 b. 3, 3 c. 4, 3 d. 4, 4 5. Using the rules of significant figures, calculate the following: 4.0021-2.009? a. 1.9931 b. 1.993 c. 1.99 d. 2.0 6. 7. 8. 9. 10. 11. 12. When an atom is electronically neutral, the number of electrons is equal to the number of. a. neutrons b. protons c. protons+ neutrons d. protons - neutrons A neutral atom will become an anion if the neutral atom. a. gains electrons b. gains protons c. loses electrons d. loses protons Isotopes are atoms of the same element that have different. a. atomic numbers b. electron configurations c. number of protons d. number of neutrons Which term describes the reproducibility of a measurement? a. accuracy b. precision c. significance d. tandem Which term describes the correctness of a measurement? a. accuracy b. grade c. precision d. significance What is the stability of the nucleus is dependent upon? a. the number of electrons b. the nucleus is always stable c. the ratio of neutrons to electrons d. the ratio of neutrons to protons This type of radiation consists of a high energy electron ejected from the nucleus a. alpha b. beta c. gamma d. Lenny 1

13. Which type of radiation is the most harmful to humans? a. alpha b. beta c. gamma d. delta 14. This type of radiation is the result of the decay of a proton into two particles. a. alpha b. electron capture c. gamma d. positron emission 15. Select the atom that is most likely to be radioactive. a. 12 6 C b. 16 8 O c. 14 6 C d. 17 8 O 16. An element, X, has two isotopes: 54 X and 55 X. If 70% of all isotopes are 54 X, then which is the average atomic mass? a. 53.8 b. 54.3 c. 54.7 d. 55.4 17. A student measured the mass of an object to be 54.5g with a volume of 26.0 ml. If the accepted value for the density is 2.55 g/ml., then what is the percent error? a. 0.45% b. 2.10% c. 18% d. 21% 18. Within an energy level, what are the regions of space where electrons can most probably be found? a. electron cloud b. energy levels c. nucleus d. orbitals 19. A neutral atom will become an anion if the neutral atom. a. gains electrons b. gains protons c. loses electrons d. loses protons 20. The third energy level contains what number of sublevels? a. 1 b. 2 c. 3 d. 4 21. When placing electrons into orbital, electrons are. a. added singly and paired only if needed b. paired as soon as possible c. never paired d. placed in any order you want 22. Which process will result in an electron in an excited state? a. absorption b. excitation c. relaxation d. transmission 23. What is the process by which an electron loses energy? a. absorption b. excitation c. relaxation d. transmission 2

24. What is the electron configuration for aluminum? a. 1s 2 2s 2 2p 1 b. 1s 2 2s 2 2p 6 3s 2 c. 1s 2 2s 2 2p 6 3s 2 3p 1 d. 1s 2 2s 2 2p 6 3s 2 3p 6 25. Which electron configuration is for an atom in an excited state? a. 1s 2 2s 2 2p 1 b. 1s 2 2s 2 2p 3 3s 1 c. 1s 2 2s 2 2p 6 d. 1s 2 2s 2 2p 6 3s 2 26. What is the major difference between a 1s orbital and a 2s orbital? a. the 2s orbital can hold more electrons b. the 2s orbital has a different shape c. the 2s orbital is at a higher energy d. the 1s orbital can hold only one electron 27. Which term describes a shared pair of electrons between two nonmetal atoms? A. covalent bond B. dipole interaction C. ionic bond D. lone pair of electrons 28. Which term describes an unshared pair of electrons on a nonmetal atom? A. covalent bond B. dipole interaction C. ionic bond D. lone pair of electrons 29. Which term describes a molecule with a nonsymmetrical electron distribution causing a build-up of charge? A. isomer B. nonpolar C. polar D. resonance 30. Which statement best describes a stable atom? A. A carbon atom with four covalent bonds. B. A nitrogen atom with three covalent bonds and a lone pair of electrons. C. An oxygen atom with two covalent bonds and two lone pairs of electrons. D. All of the above. 31. What is the geometry of ammonia, NH 3? A. bent B. linear C. planar D. pyramidal E. tetrahedral 32. What is the geometry of water, H 2 O? A. bent B. linear C. planar D. pyramidal E. tetrahedral 33. What is the geometry of carbon dioxide, CO 2? A. bent B. linear C. planar D. pyramidal E. tetrahedral 3

34. Which molecule has a Lewis structure with a tetrahedral geometry? A. CH 4 B. COCl 2 C. HCN D. AsCl 3 35. Which molecule has a Lewis structure with a trigonal planar geometry? A. CH 4 B. COCl 2 C. HCN D. AsCl 3 36. Which molecule does not contain any covalent bonds? A. CH 4 B. CuCl 2 C. H 2 SO 4 D. PBr 3 37. Which class of substances tends to be insulators and to form anions? A. halogens B. metals C. nonmetals D. semi-metals 38. In the periodic table, the elements within a family (vertical column) have similar. A. atomic masses B. isotopes C. number of filled energy levels D. valence electron configurations 39. What is the name of the group 1 elements? A. alkali metals B. alkaline earth metals C. halogens D. noble gases 40. What is the name of the group 18 elements? A. alkali metals B. alkaline earth metals C. halogens D. noble gases 41. Which scientist based his periodic table on increasing atomic number? A. Dmitri Mendeleev B. Henry Mosely C. Glen Seaborg D. Albert Einstein 42. Which scientist created the first periodic table and based it on increasing atomic mass? A. Dmitri Mendeleev B. Henry Mosely C. Glen Seaborg D. Albert Einstein 43. Which scientist left blanks in his periodic table and predicted the properties of the unknown elements that would eventually fill the blanks? A. Dmitri Mendeleev B. Henry Mosely C. Glen Seaborg D. Albert Einstein 44. The ability to attract electrons in a covalent bond is? A. atomic radius B. ionization energy C. electronegativity D. electron affinity 4

45. What is the energy needed to remove one electron form a neutral atom in a gaseous state? A. atomic radius B. ionization energy C. electronegativity D. electron affinity 46. Choose the element with the highest electronegativity. A. Nitrogen B. Oxygen C. Carbon D. Boron 47. What is the principle reasoning for the best response to #46? A. The attraction between each valence electron and the nucleus decreases with the atomic number B. As the nucleus becomes more positive, attraction to the protons increases with constant e-shielding. C. The attraction between each valence electron increases with the electron shielding D. The attraction between each valence electron and the nucleus increases with the atomic number 48. Choose the element with the largest atomic radius. A. Carbon, C B. Neon, Ne C. Tantalum, Ta D. Zinc, Zn 49. Choose the element with the highest ionization energy. A. Carbon, C B. Neon, Ne C. Tantalum, Ta D. Zinc, Zn 50. Which element is the most reactive metal? A. Fluorine B. Francium C. Lithium D. Xenon 51. Which element is the most reactive nonmetal? A. Fluorine B. Francium C. Lithium D. Xenon 52. Which is the correct name for the formula, CuNO 3?. A. copper nitrate B. copper (I) nitrate C. copper (II) nitrate D. copper (III) nitrate 53. Which set of ions would be formed by the dissociation of the ionic compound aluminum sulfate? A. Al + 1- SO 3 B. Al 3+ + 1- SO 4 C. Al 3+ + 2- SO 3 D. Al 3+ + 2- SO 4 54. How many atoms of oxygen are in Al 2 (SO 4 ) 3? A. 3 B. 4 C. 7 D. 12 5

55. What coefficient should be placed before manganese, Mn, when the following equation is balanced? _Al + _MnO _Al 2 O 3 + _Mn A. 1 B. 2 C. 3 D. 4 56. How many moles of hydrogen, H 2, are needed to react with 0.500 mol of N 2? N 2 + 3H 2 2NH 3 A. 1.00 mol B. 1.50 mol C. 2.00 mol D. 2.50 mol 57. An ion has a charge of 3+. This ion can combine with three other ions to form a neutral molecule only if each of these three ions has what charge? A. 3- B. 1- C. 1+ D. 3+ 58. Which response is the balanced equation for the reaction between magnesium fluoride and sodium sulfate to yield magnesium sulfate and sodium fluoride? A. MgF + NaSO 4 MgSO 4 + NaF B. MgF 2 + Na 2 S MgS + Na 2 F 2 C. MgF 2 + Na 2 SO 4 MgSO 4 + 2NaF D. MgF 2 + Na 2 S MgS + 2NaF 59. Consider the formula: XCl 2. X is a metal that has 24 electrons. What is a possible symbol of X? A. Ca B. Fe C. Mg D. Ti 60. Which of the following is incorrectly named? A. Fe 2 O 3, iron (II) oxide B. Mg(OH) 2, magnesium hydroxide C. NaCl, sodium chloride D. PbSO 4, lead (II) sulfate 6

For questions 61 63 use the following choices: A. PbCl 2 + HNO 3 HCl + Pb(NO 3 ) 2 B. (NH 4 ) 2 SO 4 NH 3 + H 2 SO 4 61. 62. 63. C. N 2 O + H 2 O NH 4 NO 3 D. C 5 H 10 + O 2 CO 2 + H 2 O Which choice is a decomposition reaction? Which choice is a double replacement reaction? Which choice is a combustion reaction? 64. What coefficient should be placed before ammonia, NH 3, to balance the equation? (NH 4 ) 2 SO 4 NH 3 + H 2 SO 4 A. 1 B. 2 C. 3 D. 4 65. What coefficient should be placed before hydrochloric acid, HCl, to balance the equation? PbCl 2 + HNO 3 HCl + Pb(NO 3 ) 2 A. 1 B. 2 C. 3 D. 4 66. What coefficient should be placed before iron (II) oxide, FeO, to balance the equation? Fe 2 O 3 FeO + O 2 A. 1 B. 2 C. 3 D. 4 67. What coefficient should be placed before carbon dioxide, CO 2, to balance the equation? Fe 2 O 3 + CO Fe + CO 2 A. 1 B. 2 C. 3 D. 4 68. Which molecule contains only nonpolar covalent bonds? A. CH 4 B. COCl 2 C. HCN D. FeCl 3 69. Which molecule contains a triple bond? A. CH 4 B. HCN C. COCl 2 D. AsCl 3 7

70. What piece of lab equipment do you use to heat a substance to a very high temperature? A. beaker B. crucible C. flask D. watchglass 71. In a decomposition reaction, if you begin with a total mass of 15.0 g, what total mass of product is formed? a. 5.0 g b. 10.0 g c. 15.0 g d. 20.0 g 72. 73. Which of the following is a chemical change? a. burning of gasoline in an engine b. the conversion of ice to steam c. dissolving sugar in coffee d. melting steel Which is the balanced equation for calcium and water to produce calcium hydroxide and hydrogen? a. 2Ca + 3H 2 O 2CaOH 2 + H 2 b. Ca + 2H 2 O CaOH + H 2 c. Ca + 2H 2 O Ca(OH) 2 + H 2 d. 2Ca + H 2 O Ca(OH) 2 + 2H 2 74. The fact that the total amount of mass and energy in the universe is a constant is known as the law of. a. conservation of balance b. conservation of energy c. conservation of mass d. conservation of mass and energy 75. Who discovered the idea that mass cannot be changed in an ordinary chemical reaction? a. Niels Bohr b. Stephen Hawking c. Antoine Lavoisier d. Linus Pauling 76. A chemical reaction is balanced when. a. there are an equal number of atoms for each element on both sides b. the coefficients for each type of atom are identical on both sides c. the subscripts for each type of atom are identical on both sides d. the mass of each reactant equals the mass of each product 77. Which of the following is a physical change? a. burning a piece of paper b. evaporating liquid water to steam c. fireworks exploding d. mixing two solutions and creating a gas 78. What is the empirical formula for a compound with the molecular formula C 6 H 12 Cl 2 O 2? a. CHClO b. CH 2 ClO c. C 3 H 6 ClO d. C 6 H 12 Cl 2 O 2 79. What is the empirical formula for a compound that is 30.4 % nitrogen and 69.6 % oxygen by mass? a. NO b. NO 2 c. N 2 O 3 d. N 2 O 5 8

80. What is the percent composition by mass of sulfur in the compound MgSO 4 (molar mass = 120 a. 20% b. 27 % c. 46% d. 53% g )? mol 81. What is the molar mass of ammonium phosphate, (NH 4 ) 3 PO 4? a. 112 g/mol b. 121 g/mol c. 149 g/mol d. 242 g/mol 82. The total number of moles represented by 20 g of CaCO 3 is. a. 1 mol b. 2 mol c. 0.1 mol d. 0.2 mol 83. Consider: 2CO (g) + O 2 (g) 2 CO 2 (g). What is the mole ratio of CO : CO 2 in this reaction? a. 1:1 b. 1:2 c. 2:1 d. 3:2 84. Which sample contains a total of 9.0 x 10 23 atoms? a. 0.50 mol HCl b. 0.75 mol H 2 O c. 1.5 mol Cu d. 1.5 mol H 2 85. What is the total number of nitrogen atoms in 0.25 mole of NO 2 gas? a. 1.50 x 10 23 b. 6.0 x 10 23 c. 3.0 x 10 23 d. 1.2 x 10 24 86. Which quantity of helium is represented by 1.00 mole of He atoms? a. 1.00 g b. 2.00 mol c. 6.00 x 10 23 atoms d. 4.00 L 87. If you have 1.00 mole samples of each substance, then which sample contains a total of 6.0 x 10 23 atoms? a. Li b. NH 3 c. O 2 d. CO 2 88. Each selection contains an element and an electron configuration. Which selection pairs an element with a correct excited state electron configuration for that element? A. Al - 1s 2 2s 2 2p 6 3s 2 3p 1 B. Ar - 1s 2 2s 2 2p 6 3s 2 3p 6 C. B - 1s 2 2s 1 2p 2 D. Mg - 1s 2 2s 2 2p 6 3s 2 9

89. Which atom contains 11 protons and 12 neutrons? 11 A. Na 12 23 B. Na 11 23 C. Mg 12 24 D. Mg 12 90. How many iron atoms are in a 56 g sheet of iron? A. 8.3 x 10-24 B. 56 C. 336 D. 6.0 x 10 23 91. Write the appropriate symbol in the blank. i. 197 79 Au + 0 e 1 197 78 Pt ii. 204 81 Tl 4 2 He + 200 79 Au iii. 24 Si 14 0 e 1 + 24 Al 13 iv. 226 88 Ra * 226 88 Ra + 0 0 v. 238 U 92 0 e 1 + 238 93 Np 92. How many moles are in 8.3 g of CaCO 3? A. 0.00038 mol B. 0.083 mol C. 830 mol D. 1800 mol 93. Consider the reaction between calcium oxide, CaO, and carbon, C: CaO + 3C CaC 2 + CO. What mass of carbon, C, is needed to react completely with 1 mol of calcium oxide, CaO? A. 12.0 g B. 24.0 g C. 36.0 g D. 72.0 g 10

94. How many moles are in 28 g of carbon monoxide, CO? A. 0.50 mol B. 1.0 mol C. 1.4 mol D. 2.8 mol 95. Which of the following atomic symbols is incorrect? 14 A. C 6 37 B. Cl 17 14 C. N 7 32 D. P 16 96. Which formula represents an empirical formula? A. C 2 H 4 B. C 3 H 5 C. C 4 H 12 O 6 D. C 5 H 10 97. 98. 99. How many moles are present in 9.0 g of water? A. 0.50 mol B. 1.0 mol C. 2.0 mol D. 3.6 mol In the reaction: 2KCl + 3O 2 2KClO 3, if there is a total of 10.0 g of reactant at the start of the reaction and assuming the reaction goes to completion, what mass of product should be made? A. 1.00 g B. 5.00 g C. 10.0 g D. 20.0 g An atom has only two stable isotopes. The first stable isotope has an atomic mass of 10.0 u and the other has an atomic mass of 11.0 u. Which of the following could be the atomic mass of the element? A. 9.5 u B. 10.8 u C. 11.7 u D. 12.4 u 100. How many carbon atoms are in a 12.00 g charcoal briquette made entirely of carbon, C? A. 2 B. 12 C. 6.02 x 10 23 D. 7.23 x 10 23 11