2. How many electrons appear in the Lewis symbol for an element whose electron configuration is 1s 2 2s 2 2p 4? A) 2 B) 4 C) 6 D) 8

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1 CHEM Spring Chapter 4. Sample Question 1. For representative elements, valence electrons are those electrons located A) closest to the nucleus. B) in the outermost subshell. C) in the outermost shell. D) in s orbitals. 2. How many electrons appear in the Lewis symbol for an element whose electron configuration is 1s 2 2s 2 2p 4? A) 2 B) 4 C) 6 D) 8 3. Elements in groups IA and IIIA of the periodic table possess, respectively, how many valence electrons? A) 1 and 1 B) 1 and 3 C) 3 and 1 D) 8 and 8 4. The octet rule relates to the number eight because A) only atoms with 8 valence electrons undergo chemical reaction. B) ions with charges of +8 and 8 are very stable. C) atoms, during compound formation, frequently obtain 8 valence electrons. D) all electron subshells can hold 8 electrons. 5. Formation of a positive ion is the result of an atom A) losing one or more protons. B) losing one or more electrons. C) gaining one or more protons. D) gaining one or more electrons. 6. How many total electrons are present in a N 3 ion? A) 4 B) 7 C) 10 D) 12 Page 1

2 7. Elements in groups IIA and VIIA of the periodic table would, respectively, be expected to form ions with charges of A) +2 and +7 B) -2 and -7 C) +2 and +1 D) +2 and Which of the following ions is not isoelectronic with the noble gas xenon? A) Cs + B) I - C) Sn 4+ D) Sb 3-9. The correct formula for the ionic compound containing Ga 3+ and Te 2- ions would be A) GaTe B) Ga3Te2 C) Ga2Te3 D) Ga2Te 10. The correct formula for the ionic compound formed between Na and N is A) Na3N B) NaN3 C) Na2N3 D) Na3N2 11. In which of the following ionic compounds are ions with a +1 charge present? A) Cs2Te B) Ga2Te3 C) Be2Si D) CaS 12. In which of the following pairs of compounds are both members of the pair ionic compounds? A) NF3 and HI B) Na2Se and NF3 C) KBr and H2Se D) KCl and ZnO Page 2

3 13. Which of the following statements is an accurate description of the structure of the ionic compound NaBr A) alternating layers of Na and Br atoms are present B) alternating layers of Na + and Br - ions are present C) individual molecules containing a Na + and Br - ion are present D) each cation present is surrounded by six anions in an extended array 14. The correct name for the ionic compound Al2Se3 is A) aluminum selenide B) aluminum(iii) selenide C) aluminum triselenide D) dialuminum triselenide 15. The correct name for the ionic compounds V2Se3 is A) vanadium selenide B) vanadium(iii) selenide C) vanadium triselenide D) divanadium triselenide 16. The Roman numeral (III) in the name manganese(iii) oxide indicates that A) there are three times as many manganese atoms present as oxygen atoms B) there are three manganese atoms per formula unit C) there are three oxygen atoms per formula unit D) manganese is present in the form of +3 ions 17. Which of the following compounds contains 4 atoms per formula unit? A) vanadium(iii) nitride B) lead(ii) iodide C) calcium iodide D) iron(iii) chloride 18. Which of the following statements about polyatomic ions is correct? A) all have names which end in -ate B) all must contain oxygen C) they must contain more than one atom and be charged D) all carry a charge of negative one Page 3

4 19. The formulas of the sulfate ion, the nitrate ion, and the phosphate ion are, respectively, A) SO3 2, NO3 2, PO3 2 B) SO4 2, NO4 2, PO4 2 C) SO4 2, NO3, PO4 2 D) SO4 2, NO3, PO Which one of the following compounds has a formula which contains parentheses? A) strontium carbonate B) lithium nitrate C) barium hydroxide D) ammonium nitrate 21. For which of the following elements is the listed number of valence electrons correct? A) Al 3 valence electrons B) Cl 5 valence electrons C) Si 2 valence electrons 22. Which of the following elements would have a Lewis symbol that contains 5 electrons? A) nitrogen B) fluorine C) phosphorus 23. In which of the following pairs of ions do both members of the pair contain the same total number of electrons? A) S 2 and Cl B) Na + and K + C) Al 3+ and N Which of the following elements would be expected to form a monoatomic ion with a charge of +2? A) oxygen B) sulfur C) magnesium Page 4

5 25. In which of the following pairings is the chemical formula not consistent with the ions shown? A) M 2+, X 3, M3X2 B) M 2+, X, MX2 C) M +, X 3, MX3 26. Which of the following is an incorrect statement about the number of electrons lost or gained by a representative element during ion formation? A) The number is usually 3 or less. B) The number is governed by the octet rule. C) The number is related to the position of the element in the periodic table. 27. The mechanism for ionic bond formation always involves the transferring of A) electrons from nonmetallic atoms to metallic atoms. B) protons from the nucleus of metallic atoms to the nucleus of nonmetallic atoms. C) sufficient electrons to produce ions of equal but opposite charge. 28. In which of the following pairs of ionic compounds do both members of the pair contain +1 ions? A) KCl and CaO B) Na3N and Li2S C) AlCl3 and MgF2 29. In the formation of which of the following ionic compounds is the number of electrons transferred per formula unit equal to three? A) AlN B) K3N C) BaCl2 Page 5

6 30. Which of the following pairings of compound name and compound formula is incorrect? A) sodium oxide Na2O B) magnesium sulfide MgS2 C) potassium chloride KCl 31. Which of the following ionic compounds would have a name that contains the Roman numeral III? A) AlCl3 B) FeBr3 C) Cu3N 32. In which of the following compounds is there a one-to-two ratio between positive and negative ions? A) calcium sulfide B) magnesium bromide C) lead(iv) oxide 33. In which of the following pairs of polyatomic ions do both members of the pair have the same charge? A) sulfate and phosphate B) carbonate and hydroxide C) ammonium and nitrate 34. Which of the following pairings of compound name and compound formula is incorrect? A) sodium acetate NaC2H3O2 B) barium sulfate BaSO4 C) magnesium nitrate MgNO3 Page 6

7 35. Which of the following compounds contain more than 10 atoms per formula unit? A) ammonium phosphate B) aluminum carbonate C) iron(iii) cyanide Use the following to answer questions 36-45: In each of the following multiple-choice questions, characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices a) All three statements are true. b) Two of the three statements are true. c) Only one of the statements is true. d) None of the statements is true. 36. Statements: (1) Representative elements in the same group of the periodic table have the same number of valence electrons. (2) Discrete molecules do not exist in ionic compounds. (3) A sulfate ion has one less oxygen than a sulfite ion. 37. Statements: (1) All ionic compounds which contain metal ions have names which contain Roman numerals. (2) Ionic compounds tend to have high melting points and be good conductors of electricity when in the molten state. (3) Three ions are present in one formula unit of a compound that contains Na + and O 2- ions. Page 7

8 38. Statements: (1) If an atom loses one or more electrons, it becomes negatively charged because protons now outnumber electrons. (2) Nitrogen, a group VA element, possesses 5 valence electrons. (3) Polyatomic ions are generally not very stable and usually lose their identity during chemical reactions. 39. Statements: (1) An atom with the electron configuration 1s 2 2s 2 2p 2 possesses two valence electrons. (2) The formula of the ionic compounds that contains Ba 2+ and N 3- ions is Ba2N3. (3) The polyatomic ions nitrate and azide are both tetraatomic entities. 40. Statements: (1) Ionic bonds result from the sharing of one or more pairs of electrons. (2) The compound copper(ii) phosphate contains eight oxygen atoms per formula unit. (3) Ionic compounds which contain fixed charge metals cannot contain polyatomic ions. 41. Statements: (1) The number of valence electrons possessed by an atom can never exceed four. (2) Binary ionic compounds containing two nonmetals do not occur. (3) The name of the ionic compounds Cu2S is copper(ii) sulfide. Page 8

9 42. Statements: (1) Hydrogen carbonate and bicarbonate are two names for the same polyatomic ion. (2) The symbol for an atom of X that has lost two electrons is X 2-. (3) In all ionic compounds the total charge of the ions present per formula unit must add up to zero. 43. Statements: (1) The octet rule is used to determine the number of valence electrons an atom possesses. (2) The formula for the compound sodium carbonate contains parenthesis. (3) Group IIA and VIA elements form ions which carry two units of charge. 44. Statements: (1) Calcium sulfide is a compound in which both types of ions present have the same electron configuration, that of the noble gas argon. (2) The charge on the positive ions present in the compound Al2S3 is +3. (3) The polyatomic ions ammonium and cyanide do not contain oxygen. 45. Statements: (1) The most abundant ion in hard water is usually Na +. (2) Fresh water purified for drinking purposes contains no ions. (3) Tooth enamel contains both monatomic and polyatomic ions. Page 9

10 Use the following to answer questions 46-50: For each of the element characterizations, choose the appropriate number of valence electrons present from the response. Responses on the right may be used more than once or need not be used at all. a) 1 valence electron b) 3 valence electrons c) 5 valence electrons d) 7 valence electrons 46. 1s 2 2s 2 2p 6 3s s 2 2s 2 2p 6 3s 2 3p s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p Group VA element 50. Lewis symbol is X Use the following to answer questions 51-55: For each of the ion or element combinations, choose the correct formula for the compound produced from the response. Responses on the right may be used more than once or need not be used at all. a) MX b) M2X c) MX2 d) M2X3 51. M 3+ and X M 2+ and X 53. M 2+ and X 2 Page 10

11 54. M has 2 valence electrons and X has 7 valence electrons. 55. M is a group IIIA element and X is a group VIA element. Use the following to answer questions 56-60: For each of the ionic compound characteristics, choose an ionic compound formula from the response with the stated characteristics. Responses on the right may be used more than once or need not be used at all. a) K3N b) AlF3 c) CaSO4 d) (NH4)2S monoatomic ions are present monoatomic ions are present. 58. Positive and negative ions present carry the same amount of charge. 59. More negative ions are present than positive ions. 60. Two ions are present per formula unit. Use the following to answer questions 61-65: For each of the polyatomic ion characterizations, choose the appropriate polyatomic ion from the response. Responses on the right may be used more than once or need not be used at all. a) hydroxide ion b) ammonium ion c) nitrate ion d) sulfate ion 61. Contains the elements nitrogen and hydrogen 62. Contains three oxygen atoms Page 11

12 63. Contains a total of four atoms 64. Contains one hydrogen atom 65. Has a negative two charge Use the following to answer questions 66-70: For each of the ionic compounds, choose the appropriate number of atoms contained in a formula unit from the response. Responses on the right may be used more than once or need not be used at all. a) two atoms per formula unit b) three atoms per formula unit c) four atoms per formula unit d) five or more atoms per formula unit 66. Sodium oxide 67. Calcium chloride 68. Copper(I) sulfide 69. Iron(II) hydroxide 70. Aluminum phosphate Page 12

13 Answer Key 1. C 2. C 3. B 4. C 5. B 6. C 7. D 8. C 9. C 10. A 11. A 12. D 13. D 14. A 15. B 16. D 17. D 18. C 19. D 20. C 21. A 22. D 23. D 24. C 25. C 26. E 27. E 28. B 29. D 30. B 31. B 32. D 33. E 34. C 35. D 36. B 37. B 38. C 39. D 40. C 41. C 42. B 43. C 44. A Page 13

14 45. C 46. a 47. d 48. c 49. c 50. c 51. d 52. c 53. a 54. c 55. d 56. d 57. a 58. c 59. b 60. c 61. b 62. c 63. c 64. a 65. d 66. b 67. b 68. b 69. d 70. d Page 14