Unit 4 Review
1. Consider the drawings below: 12. The least electronegative element of those listed is
Which of the following statements are true? 13. Which of the following elements has the lowest
I. The electrons in each molecule tend to be attracted to the A) Na
most electronegative element. B) Rb
II. Each molecular drawing follows the localized electron C) Ca
model. D) S
III. Both HF and CO2 are linear molecules and therefore E) Cl
IV. The bond angles of NH3 are slightly less than 109.5o 14. Which of these elements has the highest
because the lone pair compresses the angles between the electronegativity?
bonding pairs. A) Y
A) I, III, IV B) I
B) I, II, IV C) Sb
C) I, II, III D) Sr
D) II, IV E) In
E) All of the above statements (I – IV) are correct.
15. Which of the following elements has the lowest
4. Which of the following bonds would be the least polar electronegativity?
yet still be considered polar covalent? A) H
A) Mg-O B) S
B) C-O C) Cl
C) O-O D) Ca
D) Si-O E) Ba
17. Which of the following contains only non-polar bonds?
7. Draw the Lewis structures for the following compounds A) CH4
to assist you in answering this question. B) HCl
CBr2H2 BH3 XeCl4 SF4 HCl D) Mg3N2
Which compound has a see-saw shape?
A) CBr2H2 18. Which of the following has only non-polar covalent
B) BH3 bonds?
C) XeCl4 A) N2
D) SF4 B) CO
E) HCl C) HI
8. Which of the following compounds contains an ionic E) NaCl
A) HCl(g) 19. Order the following bonds from the least polar to the
B) NaCl most polar.
C) CCl4 N–O, Ca–O, C–O, O–O, Ni–O
D) SO2 A) O–O < N–O < C–O < Ca–O < Ni–O
E) O2 B) O–O < C–O < N–O < Ni–O < Ca–O
C) Ca–O < Ni–O < C–O < N–O < O–O
10. The most electronegative element of those listed is D) O–O < N–O < C–O < Ni–O < Ca–O
A) Rb E) Ni–O < Ca–O < C–O < N–O < O–O
Unit 4 Review
20. Which of the following atoms has the greatest 33. What is the number of formula units in 0.00300 moles of
A) Na A. 5.96 X 10 23
B) Rb B. 6.02 X 10 23
C) Cl C. 3.00 X 10 21
D) Se D. 1.81 X 10 21
23. If atom X forms a diatomic molecule with itself, the 34. What is the percent composition of Br in LiBr?
bond is A. 7.99%
A) ionic B. 43.42%
B) polar covalent C. 6.94%
C) non-polar covalent D. 92.01%
D) polar coordinate covalent
E) none of these 35. What is the molecular formula for a compound that is 41.39%
carbon, 3.47% hydrogen, and 55.14% oxygen, and an
27. When a molecule has a center of positive charge and a experimental molar mass of 116.07?
center of negative charge, it is said to have a ______________. A. C2H2O2
A) magnetic attraction B. C6HO6
B) diatomic bond C. C4H3O5
C) double bond D. C4H4O4
D) polyatomic ion
E) dipole moment 36. If a compound is 66.0% barium and 34.0% chlorine, what is
the empirical formula?
28. One of the most important characteristics of the water A. Ba2Cl
molecule is its ______________, which allows it to surround and B. Ba3Cl2
attract both positive and negative ions. C. BaCl2
A) polarity D. BaCl
C) magnetism 37. What is the mass, in grams, of 3.00 moles of SeOBr 2?
D) fluidity A. 764 g
E) stability B. 467 g
C. 84.92 g
29. What is the percent composition of Li in LiBr? D. 254.76 g
B. 6.94% 38. What is the formula mass for C6H3Cl3?
C. 43.42% A. 581.64
D. 92.01% B. 48.47
30. What is the molecular formula of a compound that has an D. 118.44
empirical formula of C2H4S, and an experimental molar mass of
179? 39. What is the molecular formula of a compound that has an
A. C6H12S3 empirical formula of C2H4O, and an experimental molar mass of
B. CHS 176?
C. C4H8S2 A. C4H8O2
D. C2H4S B. C2H4O
31. What is the percent of oxygen in HNO2? D. C6H12O3
B. 68.06% 40. What is the percent of hydrogen in HNO 2?
C. 14.01% A. 68.06%
D. 29.80% B. 14.01%
32. What is the molecular formula for a compound that is 64.27% D. 29.80%
carbon, 7.19% hydrogen, and 28.54% oxygen, and an
experimental molar mass of 168.19? 41. What is the percent of silver in Ag2S?
A. C12H2O4 A. 10.87%
B. C9H12O3 B. 12.94%
C. C3H4O C. 87.059%
D. C6H8O2 D. 32.07%
Unit 4 Review
42. What is the empirical formula for a compound that is 60.9% 51. What is the number of formula units in 4.27 moles of WO3?
As and 39.1% S? A. 2.57
A. AsS2 B. 4.27
B. AsS C. 2.57 X 10 24
C. As3S2 D. 4.7 X 10 23
D. As2S3 52. What is the molecular formula of a compound that has an
empirical formula of C2H2O, and an experimental molar mass of
43. What is the mass, in grams, of 488 moles of calcium 254?
carbonate? A. C4H4O2
A. 4.88 X 10 4 g B. C12H12O6
B. 6.02 X 10 23 g C. C6H6O3
C. 4.88 X 10 4 g D. C2H2O
D. 488 X 10 4 g
E. 160.1 g 53. What is the mass, in grams, of 6.00 X 10-8 moles of nicotine
44. What is the number of molecules in 0.989 moles of A. 6.02 X 10 23 g
C6H5NO2? B. 9.74 X 10 -6 g
A. 6.95 X 10 23 C. 162.24 g
B. 5.96 X 10 23 D. 973.44 g
C. 9.89 X 10 23
D. 6.02 X 10 23 54. What is the emperical formula for a compound that is 76.89%
Re and 23.12% O?
45. The mass of one mole of a compound is known as its A. ReO
A. metric mass B. ReO4
B. unknown mass C. Re2O7
C. atomic mass D. Re7O2
D. molar mass
55. In an ionic compound, the chemical formula is generally the
46. What is the percent composition of sulfur in Ag2S? same as the
A. 12.94% A. molecular formula
B. 87.059% B. molar mass
C. 10.87% C. empirical formula
D. 32.07% D. formula mass
47. What is the formula mass for Al2S3? 56. What is the molecular formula of a compound that has an
A. 194.25 empirical formula of C2H3O2, and an experimental molar mass of
B. 145.06 119?
C. 118.08 A. C6H9O6
D. 150.14 B. C2H3O2
48. What is the molecular formula for a compound that is 54.53% D. C8H12O8
carbon, 9.15% hydrogen, and 36.32% oxygen, and an
experimental molar mass of 88? 57. What is the formula mass for B4H10?
A. C5H2O3 A. 53.34
B. C10H2O5 B. 46.14
C. C4H8O2 C. 48.52
D. C4HO2 D. 57.61
49. What is the percentage of oxygen in NH4NO3? 58. A 0.858 g sample of an unknown substance is composed of
A. 5.05% 0.537 g of copper and 0.321 g of fluorine. What is the empirical
B. 35.00% formula?
C. 59.96% A. Cu3F2
D. 14.01% B. Cu5F3
50. What is the percentage of carbon in C14H10? D. Cu2F
Unit 4 Review
59. What is the formula mass for Nb5O2? 64. A 46.25 g sample contains 14.77 g of potasium, 9.06 g of
A. 556.94 oxygen, and 22.42 g of tin. What is the empirical formula?
B. 659.45 A. KSnO
C. 412.08 B. K4Sn2O6
D. 496.55 C. K2SnO3
60. A 0.0082 g sample contains 0.0015 g of nickel and 0.0067 g
of iodine. What is the empirical formula? 65. What is the percentage of hydrogen in C14H10?
A. NiI A. 5.67%
B. Ni2I3 B. 94.33%
C. NiI3 C. 12.01%
D. NiI2 D. 6.50%
61. What is the percentage of nitrogen in NH4NO3? 66. What is the percent of nitrogen in HNO2?
A. 59.96% A. 68.06%
B. 5.05% B. 29.80%
C. 14.01% C. 2.15%
D. 35.00% D. 14.01%
62. What is the formula mass for Fe2(SO4)3? 67. What type of formula gives you the simplest whole-number
A. 688.42 ratio of atoms in a compound?
B. 886.24 A. ideal formula
C. 911.82 B. empirical formula
D. 399.88 C. molecular formula
D. baby formula
63. What is the formula mass for C2H4?
A. 13.02 68. What is the percentage of hydrogen in NH4NO3?
B. 28.06 A. 59.96%
C. 14.02 B. 14.01%
D. 106.14 C. 35.00%
69. What is the number of molecules in 1500 moles of N 2H4?
A. 9.0 X 10 26
B. 6.02 X 10 23
C. 9.0 X 10 23
D. 6.02 X 10 26
Answer Key 29.A
1. B 30.A
4. E 31.B
7. D 32.B
8. B 33.D
10. E 34.D
12. C 35.D
13. B 36.C
14. B 37.A
15. E 38.C
17. E 39.C
18. A 40.C
19. D 41.C
20. C 42.D
23. C 43.A
27. E 44.B
28. A 45.D