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Name: __________________________ Date: _____________
1. How many atoms are in 4.39 g of CO2?
A) 6.01  1022 atoms
B) 1.16  1026 atoms
C) 6.04  1024 atoms
D) 1.81  1025 atoms
E) 1.80  1023 atoms
2. What is the theoretical yield of vanadium, in moles, that can be produced by the reaction
of 2.0 mole of V2O5 with 6.0 mole of calcium based on the following chemical reaction?
V2O5(s) + 5Ca(l)  2V(l) + 5CaO(s)
A) 2.4 mol
B) 2.0 mol
C) 4.0 mol
D) 1.6 mol
E) 1.0 mol
3. Liquid heptane, C7H16 , burns in oxygen gas to yield carbon dioxide and water. What
mass of carbon dioxide is produced when 15.0 mL of heptane burns completely?
(density of heptane = 0.6838 g/mL)
A) 6.59 g
B) 31.5 g
C) 71.8 g
D) 4.49 g
E) 46.1 g
4. How many carbon atoms are there in 10 lbs of sugar, C12H22O11?
A) 8.0  1024 atoms
B) 342 atoms
C) 9.6  1025 atoms
D) 159 atoms
E) 4.21 atoms
5. How many grams of sodium are there in 10. g of sodium sulfate, Na2SO4?
A) 142 g
B) 1.6 g
C) 0.32 g
D) 0.16 g
E) 3.2 g
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6. 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?
37
35
A)
Chlorine contains more 17 Cl than 17 Cl.
35
37
B)
Chlorine contains roughly equal amounts of 17 Cl and 17 Cl.
37
35
C)
Chlorine contains almost exclusively of 17 Cl, with very little 17 Cl.
35
37
D)
Chlorine contains more 17 Cl than 17 Cl.
35
37
E)
Chlorine contains almost exclusively of 17 Cl , with very little 17 Cl.
7. The percent composition by mass of a compound is 76.0% C, 12.8% H, and 11.2% O.
The molar mass of this compound is 284.5 g/mol. What is the molecular formula of the
compound?
A) C16H28O4
B) C18H36O2
C) C20H12O2
D) C9H18O
E) C10H6O
8. How many grams of water could be made from 5.0 mol H2 and 3.0 mol O2?
A) 108 g
B) 90. g
C) 45 g
D) 36 g
E) 42 g
9. The mass of 1.63  1021 silicon atoms is
A) 1.04  104 g.
B) 28.08 g.
C) 2.71  10–23 g.
D) 7.60  10–2 g.
E) 4.58  1022 g.
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10. An average atom of uranium (U) is approximately how many times heavier than an
atom of potassium?
A) 7.7 times
B) 2.4 times
C) 12.5 times
D) 6.1 times
E) 4.8 times
11. What is the coefficient of O2 when the following equation is properly balanced with the
smallest set of whole numbers?
___ CH3OH + ___ O2  ___ CO2 + ___ H2O
A) 3
B) 1
C) 7
D) 2
E) none of these
12. The mass of four moles of molecular bromine (Br2) is
A) 24  1023 g.
B) 80 g.
C) 140 g.
D) 320 g.
E) 640 g.
13. What is the coefficient of H2O when the following equation is properly balanced with
the smallest set of whole numbers?
___ Na + ___ H2O  ___ NaOH + ___ H2
A) 1
B) 2
C) 3
D) 4
E) 5
14. Calculate the mass of 4.50 moles of chlorine gas, Cl2.
A) 160 g
B) 319 g
C) 4.5 g
D) 15.7 g
E) 6.34  10–2 g
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15. Balance the following equation using the smallest set of whole numbers, then add
together the coefficients. Do not forget to count coefficients of one. The sum of the
coefficients is
__ SF4 + __ H2O  __ H2SO3 + __ HF
A) 6.
B) 7.
C) 9.
D) 4.
E) none of these.
16. Which one of the following does not represent 1.00 mol of the indicated substance?
A) 6.02  1023 Fe atoms
B) 12.01 g C
C) 6.02  1023 C atoms
D) 26.0 g Fe
E) 65.4 g Zn
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Answer Key
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