Question 1

How many grams are present in 0.885 moles of manganese?

Accepted Answer

A)  62.1 g
B)  48.6 g
C)  21.5 g
D)  27.5 g
E)  0.016 gF) C) and D)
G) A) and E)

Question 2

Once the following equation is balanced with the smallest set of whole number coefficients,what is the sum of the coefficients? (Don't forget to include coefficients of one.)  ___ CH4 + ___ Cl2 → ___ CCl4 + ___ HCl

Accepted Answer

A)  4
B)  6
C)  8
D)  10
E)  12F) B) and D)
G) B) and C)

Question 3

An oxide of gadolinium contains 86.76 mass % Gd.What is its empirical formula?

Accepted Answer

A)  Gd2O3
B)  Gd3O2
C)  Gd3O4
D)  Gd13O2
E)  GdOF) B) and E)
G) A) and D)

Question 4

Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood,pulp and textiles) . SO2(g) + 2Cl2(g) → SOCl2(g) + Cl2O(g) 
If 0.400 mol of Cl2 reacts with excess SO2,how many moles of Cl2O are formed?

Accepted Answer

A)  0.800 mol
B)  0.400 mol
C)  0.200 mol
D)  0.100 mol
E)  0.0500 molF) A) and B)
G) A) and D)

Question 5

If 3.41 g of nitrogen react with 2.79 g of hydrogen to produce ammonia,what is the limiting reactant and what mass of ammonia is produced?

Accepted Answer

A)  Hydrogen is the limiting reactant and 0.22 g of ammonia are produced.
B)  Nitrogen is the limiting reactant and 2.07 g of ammonia are produced.
C)  Nitrogen is the limiting reactant and 4.15 g of ammonia are produced.
D)  Hydrogen is the limiting reactant and 23.5 g of ammonia are produced.
E)  Hydrogen is the limiting reactant and 15.8 g of ammonia are produced.F) B) and E)
G) A) and D)

Question 6

The empirical formula is the simplest whole number ratio of atoms representing a chemical formula of a molecule.

Accepted Answer

A) True 
 B)False

Question 7

What is the maximum number of grams of ammonia,NH3,which can be obtained from the reaction of 10.0 g of H2 and 80.0 g of N2? N2 + 3H2 → 2NH3

Accepted Answer

A)  34.1 g
B)  48.6 g
C)  56.3 g
D)  90.0 g
E)  97.3 gF) A) and E)
G) All of the above

Question 8

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Accepted Answer

A)  4.00 × 102 g
B)  25.0 g
C)  17.0 g
D)  4.00 × 10-2 g
E)  2.50 × 10-3 gF) A) and B)
G) A) and C)

Question 9

There is only one distinct empirical formula for each compound that exists.

Accepted Answer

A) True 
 B)False

Question 10

What is the percent sulfur in iron(III) sulfate?

Accepted Answer

A)  28%
B)  32%
C)  24%
D)  48%
E)  42%F) A) and B)
G) A) and C)

Question 11

Potassium chlorate (used in fireworks,flares,and safety matches) forms oxygen and potassium chloride when heated. KClO3(s) → KCl(s) + O2(g) [unbalanced]
What mass of oxygen gas is formed if 26.4 g of potassium chlorate decomposes completely?

Accepted Answer

A)  223 g
B)  99.1 g
C)  10.3 g
D)  6.86 g
E)  4.60 gF) C) and D)
G) A) and B)

Question 12

Aluminum reacts with oxygen to produce aluminum oxide which can be used as an adsorbent,desiccant or catalyst for organic reactions.A mixture of 82.49 g of aluminum and 117.65 g of oxygen is allowed to react.Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete.

Accepted Answer

A)  Oxygen is the limiting reactant; 19.81 g of aluminum remain.
B)  Oxygen is the limiting reactant; 35.16 g of aluminum remain.
C)  Aluminum is the limiting reactant; 16.70 g of oxygen remain.
D)  Aluminum is the limiting reactant; 35.16 g of oxygen remain.
E)  Aluminum is the limiting reactant; 44.27 g of oxygen remain.F) B) and D)
G) B) and C)

Question 13

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?

Accepted Answer

A)  C10H6O
B)  C9H18O
C)  C16H28O4
D)  C20H12O2
E)  C18H36O2F) All of the above
G) D) and E)

Question 14

What is the mass of one copper atom? (NA = 6.022 × 1023 mol-1)

Accepted Answer

A)  1.055 × 10-22 g
B)  63.55 g
C)  1 amu
D)  1.66 × 10-24 g
E)  9.476 × 1021 gF) A) and E)
G) D) and E)

Question 15

One way of obtaining pure sodium carbonate is through the decomposition of the mineral trona, Na3(CO3)  (HCO3) ·2H2O.
2Na3(CO3)  (HCO3) ·2H2O(s) → 3Na2CO3(s) + CO2(g) + 5H2O(g) 
When 1.00 metric ton (1.00 × 103 kg) of trona is decomposed,0.650 metric ton of Na2CO3 is recovered.What is the percent yield of this reaction?

Accepted Answer

A)  92.4%
B)  72.1%
C)  65.0%
D)  48.1%
E)  35.0%F) B) and E)
G) A) and B)

Question 16

What is the coefficient of H2SO4 when the following equation is properly balanced with the smallest set of whole numbers? ___ Ca3(PO4) 2 + ___ H2SO4 → ___ CaSO4 + ___ H3PO4

Accepted Answer

A)  3
B)  8
C)  10
D)  11
E)  None of these answers is correct.F) A) and E)
G) B) and E)

Question 17

Many compounds can be represented with the same empirical formula.

Accepted Answer

A) True 
 B)False

Question 18

What is the mass of 1.63 × 1021 atoms of silicon? (NA = 6.022 × 1023 mol-1)

Accepted Answer

A)  2.71 × 10-23 g
B)  4.58 × 1022 g
C)  28.08 g
D)  1.04 × 104 g
E)  7.60 × 10-2 gF) C) and E)
G) A) and D)

Question 19

Terephthalic acid,used in the production of polyester fibers and films,is composed of carbon,hydrogen,and oxygen.When 0.6943 g of terephthalic acid was subjected to combustion analysis,it produced 1.471 g CO2 and 0.226 g H2O.What is its empirical formula?

Accepted Answer

A)  C2H3O4
B)  C3H4O2
C)  C4H3O2
D)  C5H12O4
E)  C2H2OF) D) and E)
G) A) and C)

Question 20

What mass of FeS is formed if 9.42 g of Fe reacts with 68.0 g of S8? 8Fe(s) + S8(s) → 8FeS(s)

Accepted Answer

A)  186 g
B)  142 g
C)  119 g
D)  14.8 g
E)  0.169 gF) C) and D)
G) A) and E)

Exam 3: Stoichiometry Ratios of Combination

How many grams are present in 0.885 moles of manganese?

Correct Answer
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Correct Answer
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The empirical formula is the simplest whole number ratio of atoms representing a chemical formula of a molecule.

Correct Answer
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There is only one distinct empirical formula for each compound that exists.

Correct Answer
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What is the mass of 1.63 × 10²¹ atoms of silicon? (N_A = 6.022 × 10²³ mol^-1)

Correct Answer
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What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Correct Answer
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What is the coefficient of H₂SO₄ when the following equation is properly balanced with the smallest set of whole numbers? _ Ca₃(PO₄) ₂ + _ H₂SO₄ → _ CaSO₄ + _ H₃PO₄

Correct Answer
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If 3.41 g of nitrogen react with 2.79 g of hydrogen to produce ammonia,what is the limiting reactant and what mass of ammonia is produced?

Correct Answer
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Once the following equation is balanced with the smallest set of whole number coefficients,what is the sum of the coefficients? (Don't forget to include coefficients of one.) _ CH₄ + _ Cl₂ → _ CCl₄ + _ HCl

Correct Answer
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An oxide of gadolinium contains 86.76 mass % Gd.What is its empirical formula?

Correct Answer
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What is the maximum number of grams of ammonia,NH₃,which can be obtained from the reaction of 10.0 g of H₂ and 80.0 g of N₂? N₂ + 3H₂ → 2NH₃

Correct Answer
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What is the percent sulfur in iron(III) sulfate?

Correct Answer
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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?

Correct Answer
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Potassium chlorate (used in fireworks,flares,and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) → KCl(s) + O₂(g) [unbalanced] What mass of oxygen gas is formed if 26.4 g of potassium chlorate decomposes completely?

Correct Answer
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What is the mass of one copper atom? (N_A = 6.022 × 1023 mol^-1)

Correct Answer
verified

Terephthalic acid,used in the production of polyester fibers and films,is composed of carbon,hydrogen,and oxygen.When 0.6943 g of terephthalic acid was subjected to combustion analysis,it produced 1.471 g CO₂ and 0.226 g H₂O.What is its empirical formula?

Correct Answer
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Many compounds can be represented with the same empirical formula.

Correct Answer
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Correct Answer
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What mass of FeS is formed if 9.42 g of Fe reacts with 68.0 g of S₈? 8Fe(s) + S₈(s) → 8FeS(s)

Correct Answer
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Correct Answer
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Exam 3: Stoichiometry Ratios of Combination

How many grams are present in 0.885 moles of manganese?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The empirical formula is the simplest whole number ratio of atoms representing a chemical formula of a molecule.

Correct AnswerverifiedShow Answer

There is only one distinct empirical formula for each compound that exists.

Correct AnswerverifiedShow Answer

What is the mass of 1.63 × 1021 atoms of silicon? (NA = 6.022 × 1023 mol-1)

Correct AnswerverifiedShow Answer

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

Correct AnswerverifiedShow Answer

What is the coefficient of H2SO4 when the following equation is properly balanced with the smallest set of whole numbers? ___ Ca3(PO4) 2 + ___ H2SO4 → ___ CaSO4 + ___ H3PO4

Correct AnswerverifiedShow Answer

If 3.41 g of nitrogen react with 2.79 g of hydrogen to produce ammonia,what is the limiting reactant and what mass of ammonia is produced?

Correct AnswerverifiedShow Answer

Once the following equation is balanced with the smallest set of whole number coefficients,what is the sum of the coefficients? (Don't forget to include coefficients of one.) ___ CH4 + ___ Cl2 → ___ CCl4 + ___ HCl

Correct AnswerverifiedShow Answer

An oxide of gadolinium contains 86.76 mass % Gd.What is its empirical formula?

Correct AnswerverifiedShow Answer

What is the maximum number of grams of ammonia,NH3,which can be obtained from the reaction of 10.0 g of H2 and 80.0 g of N2? N2 + 3H2 → 2NH3

Correct AnswerverifiedShow Answer

What is the percent sulfur in iron(III) sulfate?

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Potassium chlorate (used in fireworks,flares,and safety matches) forms oxygen and potassium chloride when heated. KClO3(s) → KCl(s) + O2(g) [unbalanced] What mass of oxygen gas is formed if 26.4 g of potassium chlorate decomposes completely?

Correct AnswerverifiedShow Answer

What is the mass of one copper atom? (NA = 6.022 × 1023 mol-1)

Correct AnswerverifiedShow Answer

Terephthalic acid,used in the production of polyester fibers and films,is composed of carbon,hydrogen,and oxygen.When 0.6943 g of terephthalic acid was subjected to combustion analysis,it produced 1.471 g CO2 and 0.226 g H2O.What is its empirical formula?

Correct AnswerverifiedShow Answer

Many compounds can be represented with the same empirical formula.

Correct AnswerverifiedShow Answer

Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood,pulp and textiles) . SO2(g) + 2Cl2(g) → SOCl2(g) + Cl2O(g) If 0.400 mol of Cl2 reacts with excess SO2,how many moles of Cl2O are formed?

Correct AnswerverifiedShow Answer

What mass of FeS is formed if 9.42 g of Fe reacts with 68.0 g of S8? 8Fe(s) + S8(s) → 8FeS(s)

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

Correct Answer
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Correct Answer
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Correct Answer
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Correct Answer
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What is the mass of 1.63 × 10²¹ atoms of silicon? (N_A = 6.022 × 10²³ mol^-1)

Correct Answer
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Correct Answer
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What is the coefficient of H₂SO₄ when the following equation is properly balanced with the smallest set of whole numbers? _ Ca₃(PO₄) ₂ + _ H₂SO₄ → _ CaSO₄ + _ H₃PO₄

Correct Answer
verified

Correct Answer
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Once the following equation is balanced with the smallest set of whole number coefficients,what is the sum of the coefficients? (Don't forget to include coefficients of one.) _ CH₄ + _ Cl₂ → _ CCl₄ + _ HCl

Correct Answer
verified

Correct Answer
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What is the maximum number of grams of ammonia,NH₃,which can be obtained from the reaction of 10.0 g of H₂ and 80.0 g of N₂? N₂ + 3H₂ → 2NH₃

Correct Answer
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Correct Answer
verified

Correct Answer
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Potassium chlorate (used in fireworks,flares,and safety matches) forms oxygen and potassium chloride when heated. KClO₃(s) → KCl(s) + O₂(g) [unbalanced] What mass of oxygen gas is formed if 26.4 g of potassium chlorate decomposes completely?

Correct Answer
verified

What is the mass of one copper atom? (N_A = 6.022 × 1023 mol^-1)

Correct Answer
verified

Terephthalic acid,used in the production of polyester fibers and films,is composed of carbon,hydrogen,and oxygen.When 0.6943 g of terephthalic acid was subjected to combustion analysis,it produced 1.471 g CO₂ and 0.226 g H₂O.What is its empirical formula?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

What mass of FeS is formed if 9.42 g of Fe reacts with 68.0 g of S₈? 8Fe(s) + S₈(s) → 8FeS(s)

Correct Answer
verified

Correct Answer
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