Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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How many moles of calcium are in 425 g calcium (Ca)?
a. | 10.6 mol | c. | 171 mol | b. | 70.5 mol | d. | 255 mol |
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2.
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The calculation of quantities in chemical equations is called ____.
a. | stoichiometry | c. | percent composition | b. | dimensional analysis | d. | percent yield |
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3.
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When the formula equation  is correctly balanced the
coefficient of Fe is number
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4.
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Calculate the number of atoms in 13.2 mol copper.
a. | 2.19 ´ 1023 atoms | c. | 7.95 ´ 10–23 atoms | b. | 7.95 ´ 1024 atoms | d. | 79.5 ´
1023 atoms |
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5.
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How many moles of potassium contain 3.70 ´
1023 electrons potassium?
a. | 0.615 ´ 1024 mol | c. | 0.615
mol | b. | 0.615 ´ 1023 mol | d. | 22.3 mol |
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6.
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What is the mass of 2.25 moles of sulfuric acid
(H2SO4)?
a. | 50.0 g | c. | 112 g | b. | 98.0 g | d. | 220 g |
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7.
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What is the mass of potassium chloride when 2.50 g of potassium reacts with
excess of chlorine gas?
a. | 4.77 g | c. | 9.52 g | b. | 8.57 g | d. | 728 g |
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8.
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Copper reacts with 36.7 g of silver nitrate to produce copper(II) nitrate and
silver. Determine the theoretical yield of Cu(NO3)2 if the actual yield is
31.29 g.
a. | 0.773 g | c. | 77.3 g | b. | 12.9 g | d. | 40.5 g |
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9.
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In the reaction 2CO( g) + O  ( g) ® 2CO  ( g), what is the ratio of moles
of oxygen used to moles of CO  produced?
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10.
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Hydrogen gas can be produced by reacting aluminum with sulfuric acid. How many
moles of sulfuric acid are needed to completely react with 15.0 mol of aluminum? 2Al( s) +
3H  SO  ( aq) ® Al  (SO  )  ( aq) + 3H  ( g) a. | 0.100 mol | c. | 15.0 mol | b. | 10.0 mol | d. | 22.5 mol |
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11.
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How many grams of beryllium are needed to produce 36.0 g of hydrogen? (Assume an
excess of water.) Be( s) + 2H  O( l)  Be(OH) 
( aq) + H  ( g) a. | 4.00 g | c. | 162 g | b. | 36.0 g | d. | 324 g |
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12.
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In the chemical equation H  O  ( aq) ® H  O( l)  O  ( g), the  is a ____. a. | catalyst | c. | product | b. | solid | d. | reactant |
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13.
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In the reaction Ca + Cl2 ®
CaCl2, what is the mole ratio of chlorine to calcium chloride?
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14.
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What is the ratio of the actual yield to the theoretical yield, multiplied by
100%?
a. | mole ratio | c. | molar yield | b. | percentage yield | d. | excess yield |
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15.
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Actual yield must be determined by
a. | experiments. | c. | theoretical yield. | b. | calculations. | d. | estimation. |
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16.
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For the reaction SO3 + H2O ® H2SO4, calculate the percentage yield if 500. g of
sulfur trioxide react with excess water to produce 575 g of sulfuric acid.
a. | 82.7% | c. | 91.2% | b. | 88.3% | d. | 93.9% |
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17.
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For the reaction CH4(g) + 2O2(g) ® CO2(g) + 2H2O(g), calculate the
percentage yield of carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g
of carbon dioxide.
a. | 83.88% | c. | 92.76% | b. | 89.14% | d. | 96.78% |
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18.
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Each of the four types of reaction stoichiometry problems requires using
a
a. | table of bond energies. | c. | Lewis
structure. | b. | chart of electron configurations. | d. | mole ratio. |
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19.
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In the reaction represented by the equation N2 + 3H2 ® 2NH3, what is the mole ratio of hydrogen to ammonia?
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20.
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For the reaction represented by the equation AgNO3 + NaCl ® NaNO3 + AgCl, how many moles of silver chloride, AgCl, are
produced from 7.0 mol of silver nitrate AgNO3?
a. | 1.0 mol | c. | 7.0 mol | b. | 2.3 mol | d. | 21 mol |
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Use the table below to answer the following questions.
| Element | Symbol | Atomic
Mass | | Bromine | Br | 79.90 | | Calcium | Ca | 40.08 | | Carbon | C | 12.01 | | Chlorine | Cl | 35.45 | | Cobalt | Co | 58.93 | | Copper | Cu | 63.55 | | Fluorine | F | 19.00 | | Hydrogen | H | 1.01 | | Iodine | I | 126.90 | | Iron | Fe | 55.85 | | Lead | Pb | 207.2 | | Magnesium | Mg | 24.30 | | Mercury | Hg | 200.59 | | Nitrogen | N | 14.01 | | Oxygen | O | 15.00 | | Potassium | K | 39.10 | | Sodium | Na | 22.99 | | Sulfur | S | 32.01 | | | |
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21.
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For the reaction represented by the equation 2Na + 2H2O ® 2NaOH + H2, how many grams of sodium hydroxide are produced
from 3.0 mol of sodium with an excess of water?
a. | 40. g | c. | 120 g | b. | 80. g | d. | 240 g |
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22.
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For the reaction represented by the equation 2HNO3 +
Mg(OH)2 ® Mg(NO3)2 +
2H2O, how many grams of magnesium nitrate are produced from 8.00 mol of nitric acid,
HNO3, and an excess of Mg(OH)2?
a. | 148 g | c. | 593 g | b. | 445 g | d. | 818 g |
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23.
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For the reaction represented by the equation 3Fe + 4H2O ® Fe3O4 + 4H2, how many moles of iron(III)
oxide are produced from 500. g of iron in an excess of H2O?
a. | 1.04 mol | c. | 8.95 mol | b. | 2.98 mol | d. | 12.98 mol |
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24.
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For the reaction represented by the equation 2Na + Cl2 ® 2NaCl, how many grams of sodium chloride can be produced from 500. g each
of sodium and chlorine?
a. | 112 g | c. | 409 g | b. | 319 g | d. | 824 g |
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25.
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For the reaction represented by the equation CH4 + 2O2
® 2H2O + CO2, calculate the percentage yield of
carbon dioxide if 1000. g of methane react with excess oxygen to produce 2300. g of carbon
dioxide.
a. | 83.88% | c. | 92.76% | b. | 89.14% | d. | 96.78% |
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26.
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For the reaction represented by the equation Mg + 2HCl ® H2 + MgCl2, calculate the percentage yield of
magnesium chloride if 100. g of magnesium react with excess hydrochloric acid to yield 330. g of
magnesium chloride.
a. | 71.8% | c. | 81.6% | b. | 74.3% | d. | 84.2% |
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