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
smallest unit into which a pure substance such as sugar or water can be divided, while still
retaining its composition and chemical properties is a(n) ____. a. | ion | b. | atom | c. | isotope | d. | mixture | e. | molecule | | |
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2.
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C2H4Cl2 is the formula for two possible molecules.
C2H4Cl2 is an example of a(n) a. | molecular
formula. | b. | empirical formula. | c. | condensed
formula. | d. | ionic compound formula. | e. | ball and stick
model. | | |
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3.
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Chalcopyrite is a copper containing ore. This ore contains 1 iron atom and 2 sulfur
atoms for each copper atom. What is the formula of chalcopyrite? a. | CuFeS | b. | CuFe(2S) | c. | CuFeS2 | d. | 2SCuFe | e. | CuFeS2 | | |
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4.
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What
is the molar mass of cobalt(II) iodide hexahydrate? a. | 212.8
g/mol | b. | 293.9 g/mol | c. | 312.7
g/mol | d. | 420.8 g/mol | e. | 465.1
g/mol | | |
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5.
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What
is the molar mass of ammonium sulfate? a. | 110.0 g/mol | b. | 114.1
g/mol | c. | 132.1 g/mol | d. | 144.6
g/mol | e. | 168.9 g/mol | | |
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6.
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How
many moles are in 35.7 g of anhydrous copper(II) sulfate? a. | 0.160
mol | b. | 0.224
mol | c. | 0.762
mol | d. | 4.47
mol | e. | 5.70
x 103
mol | | |
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7.
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How
many moles are in 4.5 g of AgNO3? a. | 1.3
x 10-3 mol | b. | 2.6
x 10-2
mol | c. | 0.61
mol | d. | 38
mol | e. | 7.6
x 102
mol | | |
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8.
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How
many grams are in 0.0751 mol Br2? a. | 4.70
x 10-4 g | b. | 0.0833
g | c. | 2.13
g | d. | 6.00
g | e. | 12.0
g | | |
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9.
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How
many grams are in 0.50 mol iron(II) sulfide? a. | 0.057 g | b. | 8.2
g | c. | 18
g | d. | 44.0
g | e. | 1.8
x 102
g | | |
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10.
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What
is a correct method to determine the number of oxygen atoms in 8.12 g of carbon
dioxide?
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11.
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How
many oxygen atoms are in 1.50 mol of SO3? a. | 7.71
x 1021
atoms | b. | 1.12 x 1022 atoms | c. | 3.01
x 1022
atoms | d. | 9.03 x 1023 atoms | e. | 2.71
x 1024
atoms | | |
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12.
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If
1.00 g of an unknown molecular compound contains 4.55 x 1021 molecules, what is its molar
mass? a. | 44.0
g/mol | b. | 66.4 g/mol | c. | 72.1
g/mol | d. | 98.1 g/mol | e. | 132
g/mol | | |
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13.
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What
is the mass percent of chlorine in iron(II) chloride? a. | 14.0% | b. | 28.0% | c. | 44.1% | d. | 55.9% | e. | 66.7% | | |
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14.
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What
is the mass percent of each element in dichloromethane,
CH2Cl2? a. | 10.06% C, 60.24% H, 29.70% Cl | b. | 20.00% C, 20.00%
H, 60.00% Cl | c. | 24.10% C, 3.11% H, 72.79% Cl | d. | 33.87% C, 0.22%
H, 65.91% Cl | e. | 14.14% C, 2.37% H, 83.48% Cl | | |
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15.
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Nitrogen and oxygen form an extensive series of oxides with the general formula
NxOy. What is the empirical formula for an oxide that contains 46.68%
nitrogen? a. | N2O | b. | NO | c. | NO2 | d. | N2O3 | e. | N2O5 | | |
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16.
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A
molecule is found to contain 47.35% C, 10.60% H, and 42.05% O. What is the empirical formula for this
molecule? a. | C2H6O | b. | C3H4O2 | c. | C3H8O2 | d. | C4H6O2 | e. | C4H8O3 | | |
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17.
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Phosphorus, P, is combined with chlorine, Cl2, to give a gaseous compound
with the formula PClx. If you start with 2.097 g of P and isolate 9.298 g of
PClx, what is the value of x?
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18.
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In a
chemical reaction, 1.000 g of sulfur (S8) combines with 3.963 g of copper to give a pure
compound. What is the empirical formula of this compound? a. | Cu2S | b. | CuS | c. | CuS2 | d. | Cu3S2 | e. | Cu2S3 | | |
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19.
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A
4.450 g sample of hydrated lithium iodide, LiI·xH2O, is dried in an oven. When the
anhydrous salt is removed from the oven, its mass is 3.170 g. What is the value of
x?
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20.
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A
2.000 g sample of CoCl2·xH2O is dried in an oven. When the anhydrous salt
is removed from the oven, its mass is 1.565 g. What is the value of x?
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