Question 1

If 13.9 g of oxygen react with 33.7 g of calcium to produce calcium oxide, what is the limiting reactant and what mass of calcium oxide is produced?

Accepted Answer

A)  Calcium is the limiting reactant and 47.2 g of calcium oxide are produced. 
B)  Oxygen is the limiting reactant and 24.4 g of calcium oxide are produced. 
C)  Calcium is the limiting reactant and 60.6 g of calcium oxide are produced. 
D)  Oxygen is the limiting reactant and 48.7 g of calcium oxide are produced. 
E)  Calcium is the limiting reactant and 23.6 g of calcium oxide are produced. 
A)  Calcium is the limiting reactant and 47.2 g of calcium oxide are produced. 
B)  Oxygen is the limiting reactant and 24.4 g of calcium oxide are produced. 
C)  Calcium is the limiting reactant and 60.6 g of calcium oxide are produced. 
D)  Oxygen is the limiting reactant and 48.7 g of calcium oxide are produced. 
E)  Calcium is the limiting reactant and 23.6 g of calcium oxide are produced.

Question 2

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

Accepted Answer

A) True 
 B)False

Question 3

Calculate the molar mass of sulfuric acid.

Accepted Answer

A)  98.086 g/mol 
B)  81.078 g/mol 
C)  49 g/mol 
D)  41 g/mol 
E)  None of the answers are correct. 
A)  98.086 g/mol 
B)  81.078 g/mol 
C)  49 g/mol 
D)  41 g/mol 
E)  None of the answers are correct.

Question 4

The ________ is the amount of product physically collected from a chemical reaction and is typically less than the theoretical yield.

Accepted Answer

The answer of The ________ is the amount of product...

Question 5

How many grams of water could be made from 5.0 mol H2 and 3.0 mol O2?

Accepted Answer

A)  90. g 
B)  36 g 
C)  42 g 
D)  45 g 
E)  108 g 
A)  90. g 
B)  36 g 
C)  42 g 
D)  45 g 
E)  108 g

Question 6

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.) ________ Cr + ________ H2SO4 → ________ Cr2(SO4)3 + ________ H2

Accepted Answer

A)  4 
B)  9 
C)  11 
D)  13 
E)  15 
A)  4 
B)  9 
C)  11 
D)  13 
E)  15

Question 7

What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s)

Accepted Answer

A)  1.94 kg 
B)  1.51 kg 
C)  754 g 
D)  205 g 
E)  51.3 g 
A)  1.94 kg 
B)  1.51 kg 
C)  754 g 
D)  205 g 
E)  51.3 g

Question 8

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)  GdO 
A)  Gd2O3 
B)  Gd3O2 
C)  Gd3O4 
D)  Gd13O2 
E)  GdO

Question 9

Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

Accepted Answer

A)  2.377 mol 
B)  2.146 mol 
C)  1.105 mol 
D)  0.4660 mol 
E)  0.4207 mol 
A)  2.377 mol 
B)  2.146 mol 
C)  1.105 mol 
D)  0.4660 mol 
E)  0.4207 mol

Question 10

Smooth muscle myosin is a motor protein that plays a crucial role in the contraction of smooth muscle. If this protein has a molar mass of 480,000 grams/mol, what is the mass, in grams, of 27 moles of smooth muscle myosin?

Accepted Answer

A)  1.8 × 104 g 
B)  1.3 × 107 g 
C)  1.8 × 102 g 
D)  2.8 × 1029 g 
E)  None of the answers is correct. 
A)  1.8 × 104 g 
B)  1.3 × 107 g 
C)  1.8 × 102 g 
D)  2.8 × 1029 g 
E)  None of the answers is correct.

Question 11

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.) ________ Al + ________ H2SO4 → ________ Al2(SO4)3 + ________ H2

Accepted Answer

A)  3 
B)  5 
C)  6 
D)  9 
E)  12 
A)  3 
B)  5 
C)  6 
D)  9 
E)  12

Question 12

What mass of oxygen is required to react with calcium to produce 44.8 g calcium oxide?

Accepted Answer

A)  12.8 g 
B)  25.6 g 
C)  6.39 g 
D)  0.399 g 
E)  51.1 g 
A)  12.8 g 
B)  25.6 g 
C)  6.39 g 
D)  0.399 g 
E)  51.1 g

Question 13

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. 
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.

Question 14

What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers?
________ Na + ________ H2O → ________ NaOH + ________ H2

Accepted Answer

Question 15

What is the average 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 g 
A)  1.055 × 10-22 g 
B)  63.55 g 
C)  1 amu 
D)  1.66 × 10-24 g 
E)  9.476 × 1021 g

Question 16

Phosphine, an extremely poisonous and highly reactive gas, reacts with oxygen gas to form tetraphosphorus decaoxide and water. PH3(g) + O2(g) → P4O10(s) + H2O(g) [unbalanced]
Calculate the mass of P4O10(s) formed when 225 g of PH3 reacts with excess oxygen.

Accepted Answer

A)  1880 g 
B)  940. g 
C)  900. g 
D)  470. g 
E)  56.3 g 
A)  1880 g 
B)  940. g 
C)  900. g 
D)  470. g 
E)  56.3 g

Question 17

Hydroxyl ammonium nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. If its molar mass is between 94 and 98 g/mol, what is its molecular formula?

Accepted Answer

A)  NH2O5 
B)  N2H4O4 
C)  N3H3O3 
D)  N4H8O2 
E)  N2H2O4 
A)  NH2O5 
B)  N2H4O4 
C)  N3H3O3 
D)  N4H8O2 
E)  N2H2O4

Question 18

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

Question 19

Phosphorus pentachloride, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of phosphorus pentachloride.

Accepted Answer

A)  5.38 mol 
B)  3.55 mol 
C)  0.583 mol 
D)  0.282 mol 
E)  0.186 mol 
A)  5.38 mol 
B)  3.55 mol 
C)  0.583 mol 
D)  0.282 mol 
E)  0.186 mol

Question 20

How many grams of magnesium oxide remain after 18.50 g of magnesium oxide reacts with 30.30 g hydrochloric acid to produce magnesium chloride and water?

Accepted Answer

The answer of How many grams of magnesium oxide remain...

Exam 3: Stoichiometry: Ratios of Combination

If 13.9 g of oxygen react with 33.7 g of calcium to produce calcium oxide, what is the limiting reactant and what mass of calcium oxide is produced?

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

Calculate the molar mass of sulfuric acid.

The ________ is the amount of product physically collected from a chemical reaction and is typically less than the theoretical yield.

How many grams of water could be made from 5.0 mol H2 and 3.0 mol O2?

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.) ________ Cr + ________ H2SO4 → ________ Cr2(SO4)3 + ________ H2

What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl2(l) + 4NaF(s) → SF4(g) + S2Cl2(l) + 4NaCl(s)

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

Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

Smooth muscle myosin is a motor protein that plays a crucial role in the contraction of smooth muscle. If this protein has a molar mass of 480,000 grams/mol, what is the mass, in grams, of 27 moles of smooth muscle myosin?

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.) ________ Al + ________ H2SO4 → ________ Al2(SO4)3 + ________ H2

What mass of oxygen is required to react with calcium to produce 44.8 g calcium oxide?

What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers? ________ Na + ________ H2O → ________ NaOH + ________ H2

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

Phosphine, an extremely poisonous and highly reactive gas, reacts with oxygen gas to form tetraphosphorus decaoxide and water. PH3(g) + O2(g) → P4O10(s) + H2O(g) [unbalanced] Calculate the mass of P4O10(s) formed when 225 g of PH3 reacts with excess oxygen.

Hydroxyl ammonium nitrate contains 29.17 mass % N, 4.20 mass % H, and 66.63 mass % O. If its molar mass is between 94 and 98 g/mol, what is its molecular formula?

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?

Phosphorus pentachloride, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of phosphorus pentachloride.

How many grams of magnesium oxide remain after 18.50 g of magnesium oxide reacts with 30.30 g hydrochloric acid to produce magnesium chloride and water?

Chemistry: the Central Science

Atoms, Molecules, and Ions

Reactions in Aqueous Solutions

Thermochemistry

Quantum Theory and the Electronic Structure of Atoms

Electron Configuration and the Periodic Table

Chemical Bonding I: Basic Concepts

Chemical Bonding II: Molecular Geometry and Bonding Theories

Gases

Intermolecular Forces and the Physical Properties of Liquids and Solids

Modern Materials

Physical Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acids and Bases

Acid-Base Equilibria and Solubility Equilibria

Entropy, Free Energy, and Equilibrium

Electrochemistry

Nuclear Chemistry

Environmental Chemistry

Coordination Chemistry

Metallurgy and the Chemistry of Metals

Nonmetallic Elements and Their Compounds

Organic Chemistry

Filters

How many grams of water could be made from 5.0 mol H₂ and 3.0 mol O₂?

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.) Cr + H₂SO₄→ Cr₂(SO₄)₃+_{________}H₂

What mass of sodium fluoride (used in water fluoridation and the manufacture of insecticides) is required to form 485 g of sulfur tetrafluoride? 3SCl₂(l) + 4NaF(s) → SF₄(g) + S₂Cl₂(l) + 4NaCl(s)

Aluminum oxide, Al₂O₃, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al₂O₃.

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.) Al + H₂SO₄→ Al₂(SO₄)₃ + H₂

What is the coefficient of H₂O when the following equation is properly balanced with the smallest set of whole numbers? Na + H₂O → NaOH + H₂

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

Phosphine, an extremely poisonous and highly reactive gas, reacts with oxygen gas to form tetraphosphorus decaoxide and water. PH₃(g) + O₂(g) → P₄O₁₀(s) + H₂O(g) [unbalanced] Calculate the mass of P₄O₁₀(s) formed when 225 g of PH₃ reacts with excess oxygen.

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?