Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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The
combustion of propane produces carbon dioxide and steam.
C3H8(g) + 5 O2(g)
→ 3
CO2(g) + 4 H2O(g)
All of the following statements concerning this reaction are correct
EXCEPT
a. |
three molecule
of carbon dioxide are formed per one molecule of propane consumed. | b. |
five molecules
of oxygen are consumed per one molecule of propane consumed. | c. |
four moles of
steam are formed per five moles of oxygen consumed. | d. |
the combined
mass of reactants consumed equals the mass of products formed. | e. |
three grams of
carbon dioxide are formed per five grams of oxygen consumed. | | |
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2.
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Ammonia is prepared by reacting nitrogen and hydrogen gases at high temperature
according to the unbalanced chemical equation below.
__ N2(g) + __ H2(g)
→ __
NH3(g)
What are the respective coefficients when the equation
is balanced with the smallest whole numbers?
a. |
1, 1, 1 | b. |
1, 3,
1 |
c. |
1, 3,
2 |
d. |
2, 1,
2 |
e. |
2, 3,
2 | | |
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3.
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The
products of the complete combustion of a hydrocarbon are carbon dioxide and water. Write a balanced
chemical equation for the combustion of pentane, C5H12. a. |
C5H12(g) + 8 O2(g) → 5
CO2(g) + 6 H2O(g) |
b. |
C5H12(g)
→ 5 C(s) + 6
H2(g) |
c. |
C5H12(g) + 9 O2(g)
→ 4
CO2(g) + 5 H2O(g) |
d. |
C5H12(g) + 11 O2(g)
→
C5O10(g) + 6 H2O(g) | e. |
C5H12(g) + 11 O2(g) → 5
CO2(g) + 12 H2O(g) | | |
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4.
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Aluminum reacts with oxygen to produce aluminum oxide.
4 Al(s) + 3 O2(g) → 2 Al2O3(s)
If 5.0 moles of Al react with excess O2, how many moles of
Al2O3 can be formed?
a. |
1.0 mol | b. |
2.0
mol |
c. |
2.5
mol |
d. |
5.0
mol |
e. |
10.0
mol | | |
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5.
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The
complete combustion of 0.40 moles of butane gas, C4H10, will a. |
consume 0.40 mol
O2 and produce 0.20 mol CO2. | b. |
consume 0.80 mol
O2 and produce 0.40 mol CO2. | c. |
consume 1.3 mol
O2 and produce 0.80 mol CO2. | d. |
consume 2.6 mol
O2 and produce 1.6 mol CO2. | e. |
consume 5.2 mol
O2 and produce 3.2 mol CO2. | | |
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6.
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What
mass of oxygen is consumed by the complete combustion of 23.0 grams of
ethylene?
C2H4(g) + 3 O2(g)
→ 2
CO2(g) + 2 H2O(g)
a. |
8.75 g | b. |
26.2
g |
c. |
60.5
g |
d. |
69.0
g |
e. |
78.7
g | | |
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7.
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What
is a correct method for determining how many grams of oxygen react with 1.00 gram of
pentane?
C5H12(g) + 8 O2(g)
→ 5
CO2(g) + 6 H2O(g)
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8.
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What
is a correct method for determining how many moles of calcium oxide are produced in the reaction of
10.0 g calcium with excess oxygen?
2 Ca(s) +
O2(g) → 2 CaO(s)
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9.
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Polyethylene is a polymer consisting of only carbon and hydrogen. If 3.000 g of the
polymer is burned in oxygen it produces 3.855 g H2O and 9.414 g CO2. What is
the empirical formula for polyethylene?
a. |
CH2 | b. |
C2H |
c. |
C2H3 | d. |
C5H8 |
e. |
C7H8 | | |
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10.
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Cyclohexene, a hydrocarbon, has a molar mass of 82.1 g/mole. If the combustion of
0.8300 g cyclohexene produces 0.9102 g H2O and 2.668 g CO2, what is the
molecular formula of this compound?
a. |
C3H5 | b. |
C5H22 |
c. |
C6H10 | d. |
C6H14 |
e. |
C7H10 | | |
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11.
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A
reaction which forms a solid product is an example of a(n)________. a. |
oxidation-reduction reaction | b. |
combustion
reaction |
c. |
precipitation reaction | d. |
gas evolution
reaction |
e. |
none of the above | | |
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12.
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Which
of the following statements about balancing reactions is FALSE?
a. |
If there is no
coefficient or subscript, a one is implied. | b. |
By adding a
coefficient, we change the properties of the compound in a chemical
reaction. |
c. |
Subscripts are multiplied by the coefficients to determine the
number of atoms in a compound. |
d. |
Coefficients are added to compounds to ensure both sides of the
reaction have equal numbers of each atom. |
e. |
All of the above statements are true.
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13.
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Before a chemical equation can be written, one must know a. |
the atomic mass
of all the elements involved. |
b. |
the molar mass of all the compounds. | c. |
the symbols and
formulas of all reactants and products. |
d. |
the symbols and formulas of all reactants and products.
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e. |
none of the
above. | | |
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14.
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When
the equation, ___N2 + ___H2 → ___NH3
is balanced, the coefficient of hydrogen is
a. |
1 |
b. |
2 |
c. |
3 |
d. |
4 |
e. |
none of the above | | |
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15.
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What
are the coefficients for the following reaction when it is properly
balanced?
___CH4 + ___O2
→
___CO2 + ___H2O
a. |
2, 1, 3, 1 | b. |
1, 3, 2,
1 |
c. |
2, 3, 2,
2 |
d. |
1, 2, 1, 2
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e. |
none of the
above | | |
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16.
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How
many moles of water are made from the reaction of 2.2 moles of oxygen gas?
Given the
reaction: 2H2 + O2 → 2H2O a. |
4.4 mol
H2O |
b. |
2.2 mol H2O | c. |
1.1 mol
H2O |
d. |
3.3 mol H2O | e. |
not enough
information | | |
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17.
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How
many moles of chlorine gas are needed to make 0.6 moles of sodium
chloride?
Given the reaction: 2Na + Cl2 ? 2NaCl
a. |
0.6 mol NaCl
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b. |
0.3 mol NaCl |
c. |
1.2 mol NaCl |
d. |
3.6 mol NaCl |
e. |
not enough
information | | |
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18.
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How
many grams of water are made from the reaction of 16.0 grams of oxygen
gas?
Given the reaction: 2H2 + O2 →
2H2O
a. |
9.00
g |
b. |
16.0
g |
c. |
18.0
g |
d. |
36.0
g |
e. |
not enough
information | | |
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19.
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How
many grams of chlorine gas are needed to make 117 grams of sodium chloride?
Given the reaction: 2Na + Cl2 → 2NaCl
a. |
35.5 g
Cl2 |
b. |
71.0 g Cl2 | c. |
48.2 g
Cl2 |
d. |
142 g Cl2 | e. |
not enough
information | | |
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20.
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How
many grams of sodium metal are needed to make 29.3 grams of sodium chloride?
Given the reaction: 2Na + Cl2 → 2NaCl
a. |
46.0 g
Na |
b. |
23.0 g
Na |
c. |
11.5 g
Na |
d. |
5.75 g
Na |
e. |
not enough
information | | |
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