GENERAL CHEMISTRY I – CHM201
Unit 2 Practice Test
This test is intended to help you get acquainted with the types of questions you will be asked on the Unit Test administered at
the end of the unit. The answers are included at the end of the test. Do not pass in your answers to this test. This is optional
and will not be graded. Feel free to seek any help you wish on these questions. A mastery of the topics covered in them will
assure a good performance on the tests that count.
1. There are two stable isotopes of chlorine: chlorine-35, with a mass of 34.968853 amu; and chlorine-37, with a mass of 36.965903.
Given that the average atomic mass of a chlorine atom is 35.45 amu, which of the following statements is true?
A) Chlorine contains almost exclusively
B) Chlorine contains more
Cl than
CI with very little
Cl.
C) Chlorine contains roughly equal amounts of
D) Chlorine contains more
Cl than
E) Chlorine contains almost exclusively of
Cl.
Cl and
Cl.
Cl.
Cl, with very little
Cl.
2. Calculate the average atomic mass of unknown element X using the following data:
Isotope
107X
Abundance
Mass
51.839%
106.9051amu
109X
48.161%
108.9048amu
A) 106.91 amu
B) 108.00 amu
C) 107.90 amu
D) 107.87 amu
E) 108.90 amu
3. Determine the number of moles of aluminum in 96.7 g of Al.
A) 0.279 mol
B) 3.58 mol
C) 7.43 mol
D) 4.21 mol
E) 6.02 × 1023 mol
4. Calculate the number of moles of cesium in 40.0g of cesium.
A) 0.286 mol
B) 2.12 mol
C) 0.301 mol
D) 2.24 mol
E) 0.0200 mol
5. Calculate the molecular mass of menthol, C10H20O.
A) 156.26 amu
B) 140.26 amu
C) 29.02 amu
D) 48.17 amu
E) 137.11 amu
6. Calculate the mass of 0.00456 moles of (NH4)2SO4.
A) 132 g
B) 3.45 x 10-5 g
C) 114 g
D) 0.603 g
E) 0.520 g
7. How many moles of O are in 2.45 moles of H2CO3?
A) 2.45 moles O
B) 39.2 moles O
C) 118 moles O
D) 7.35 moles O
E) 0.459 moles O
8. How many moles of C are there in 65.2 g CHCl3?
A) 0.183 mol
B) 0.363 mol
C) 0.547 mol
D) 1.10 × 1023 mol
E) 1.00 mol
9. How many grams of nitrogen are there in 7.5 g of Ca(NO 3)2?
A) 0.64 g
B) 1.3 g
C) 0.15 g
D) 1.2 g
E) 2.3 g
10. Calculate the mass of 4.50 moles of chlorine gas, Cl2.
A) 6.34 × 10–2 g
B) 4.50 g
C) 15.7 g
D) 160. g
E) 319 g
11. The mineral hausmannite is a compound of 55Mn and 16O. If 72% of the mass of hausmannite is due to manganese, what is the
empirical formula of hausmannite?
A) MnO
B) Mn3O
C) Mn3O4
D) Mn4O3
E) MnO3
12. A compound with an empirical formula of C2H3Br2 has a molar mass of 373.69 g/mol. What is the molecular formula?
A) C2H3Br2
B) CHBr
C) C6H9Br6
D) C4H6Br2
E) C4H6Br4
13. What is the coefficient of O2 when the following equation is properly balanced?
___ CH3OH + ___ O2 → ___ CO2 + ___ H2O
A) 1
B) 2
C) 3
D) 7
E) none of these
14. When 22.0 g NaCl and 21.0 g H2SO4 are mixed and react according to the equation below, which is the limiting reagent?
2NaCl + H2SO4 → Na2SO4 + 2HCl
A) NaCl
B) H2SO4
C) Na2SO4
D) HCl
E) No reagent is limiting.
15. Sulfur dioxide gas reacts with oxygen gas and water according to the chemical reaction below. When 4.5 g of SO 2 are mixed with
excess O2 and H2O, how many grams of H2SO4 are produced?
2SO2(g) + O2(g) + 2H2O(l) → 2H2SO4(l)
A) 4.5 g
B) 440 g
C) 9.0 g
D) 14 g
E) 6.9 g
16. A sample of aluminum metal is placed in a graduated cylinder. It is noted that 5.50 mL of water is displaced by the aluminum. The
aluminum is then reacted with excess nitric acid to produce aluminum nitrate and hydrogen gas. Given the density for aluminum is
2.702 g/mL, how many grams of aluminum nitrate are produced in the reaction?
2Al(s) + 6HNO3(aq) → 2Al(NO3)3(aq) + 3H2(g)
A) 161 g
B) 11.0 g
C) 14.9 g
D) 117 g
E) 235 g
17. The first step in the Ostwald process for producing nitric acid is
4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g).
If the reaction of 150. g of ammonia with 150. g of oxygen gas yields 87. g of nitric oxide (NO), what is the percent yield of this
reaction?
A) 33%
B) 49%
C) 62%
D) 77%
E) 100%
18. Identify the major ionic species present in an aqueous solution of FeCl3.
A) Fe+, Cl3B) Fe3+, Cl33C) Fe3+, 3 ClD) Fe2+, 3 ClE) Fe+, 3 Cl-
19. Based on the solubility rules, which of the following should be soluble in water?
A) Hg2Cl2
B) Na2S
C) Ag2CO3
D) Ag2S
E) BaSO4
20. Which of the following will occur when a solution of Pb(NO 3)2(aq) is mixed with a solution of KI(aq)?
A) A precipitate of KNO3 will form; Pb2+ and I– are spectator ions.
B) No precipitate will form.
C) A precipitate of Pb(NO3)2 will form; K+ and I– are spectator ions.
D) A precipitate of PbI2 will form; K+ and NO3– are spectator ions.
E) A precipitate of PbI2 will form; Pb2+ and I– are spectator ions.
21. Identify the correct net ionic equation for the reaction that occurs when solutions of Ba(ClO4)2 and K2SO4 are mixed.
A) Ba2+(aq) + SO42-(aq) → BaSO4(s)
B) 2K+(aq) + 2ClO4-(aq) → K2(ClO4)2(s)
C) K+(aq) + ClO4-(aq) → KClO4(s)
D) Ba(ClO4)2(aq) + K2SO4(aq) → BaSO4(s) + 2KClO4(s)
E) Ba2+(aq) + K+(aq) + SO42-(aq) → KBaSO4(s)
22. The oxidation number of Cr in Cr2O72– is
A) –12.
B) –7.
C) –2.
D) +6.
E) +7.
23. Which of the following equations does not represent an oxidation-reduction reaction?
A) 3Al + 6HCl → 3H2 + AlCl3
B) 2H2O → 2H2 + O2
C) 2NaCl + Pb(NO3)2 → PbCl2 + 3NaNO3
D) 2NaI + Br2 → 2NaBr + I2
E) Cu(NO3)2 + Zn → Zn(NO3)2 + Cu
24. What element is reduced in the following chemical reaction?
Cu + 2H2SO4 → CuSO4 + SO2 + 2H2O
A) Cu
B) H
C) S
D) O
E) H2O
25. What mass of C12H22O11 (sucrose) is needed to prepare 255 mL of a 0.570 M solution of sucrose in water?
A) 49.8 g
B) 145 g
C) 153 g
D) 0.145 g
E) 447 g
26. A 0.9182 g sample of CaBr2 is dissolved in enough water to give 0.500 L of solution. What is the calcium ion concentration in this
solution?
A) 9.19 × 10–3 M
B) 2.30 × 10–3 M
C) 2.72 × 10–3 M
D) 4.59 × 10–3 M
E) 1.25 × 10–3 M
27. What volume of concentrated nitric acid (15.0 M) is required to make 125 mL of a 3.0 M nitric acid solution?
A) 25 mL
B) 37.5 mL
C) 50 mL
D) 63 mL
E) None of the above
28. During a titration the following data were collected. A 25 mL portion of an unknown monoprotic acid solution was titrated with
1.0 M NaOH; 40.0 mL of the base were required to neutralize the sample. What is the molarity of the acid solution?
A) 1.6 M
B) 1.2 M
C) 0.80 M
D) 0.40 M
E) None of the above
Answers
1. B
2. D
3. B
4. C
5. A
6. D
7. D
8. C
9. B
10. E
11. C
12. E
13. C
14. A
15. E
16. D
17. D
18. C
19. B
20. D
21. A
22. D
23. C
24. C
25. A
26. A
27. A
28. A