Question 1

Which of the following has the lowest percent of oxygen?

Accepted Answer

A)  N₂O 
B)  AL₂O₃ 
C)  K₂CO₃ 
D)  KMnO₄ 
A)  N₂O 
B)  AL₂O₃ 
C)  K₂CO₃ 
D)  KMnO₄

Question 2

The balanced equation involves the corresponding coefficients ________. NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

Accepted Answer

A)  1: 1: 1: 1 
B)  1: 2: 1: 1 
C)  2: 1: 1: 1 
D)  2: 1: 2: 1 
A)  1: 1: 1: 1 
B)  1: 2: 1: 1 
C)  2: 1: 1: 1 
D)  2: 1: 2: 1

Question 3

The balanced equation involves the corresponding coefficients ________. C₆H14 + O₂ → CO₂ + H₂O

Accepted Answer

A)  1: 9: 6: 7 
B)  1: 10: 6: 7 
C)  2: 19: 12:14 
D)  2: 21: 6: 7 
A)  1: 9: 6: 7 
B)  1: 10: 6: 7 
C)  2: 19: 12:14 
D)  2: 21: 6: 7

Question 4

The molecular mass of a compound X(NO₃)3 is 213. The atomic mass of X is ________, which is ________.

Accepted Answer

A)  27; Al 
B)  51; V 
C)  56; Fe 
D)  59; Co 
A)  27; Al 
B)  51; V 
C)  56; Fe 
D)  59; Co

Question 5

What is the percentage by mass of iron (Fe) in the mineral hematite (Fe2O₃)?

Accepted Answer

A)  40% 
B)  60% 
C)  70% 
D)  30% 
A)  40% 
B)  60% 
C)  70% 
D)  30%

Question 6

18 g of water have the same number of atoms as 48 g of ozone.

Accepted Answer

A) True 
 B)False

Question 7

0.68 g of sulfur combine with 1.51 g of chlorine. The empirical formula of this compound is ________.

Accepted Answer

A)  SCl 
B)  SCL₂ 
C)  SCl4 
D)  SCl6 
A)  SCl 
B)  SCL₂ 
C)  SCl4 
D)  SCl6

Question 8

Alkenes have the general molecular formula CnH₂n. Thus, when n = 2, the alkene is C₂H₄. If an alkene has a molecular mass between 65 and 75, this alkene is ________.

Accepted Answer

A)  C₅H₁₂ 
B)  C₅H₁₀ 
C)  C₆H₃ 
D)  C₆H₁₂ 
A)  C₅H₁₂ 
B)  C₅H₁₀ 
C)  C₆H₃ 
D)  C₆H₁₂

Question 9

One mole of carbon monoxide has the same mass as one mole of nitrogen gas.

Accepted Answer

A) True 
 B)False

Question 10

If the empirical formula of a compound is CH₂O and the molecular weight is 180, the molecular formula is ________.

Accepted Answer

A)  CH₂O 
B)  C₂H₄O₂ 
C)  C₃H₆O₃ 
D)  C₆H₁₂O6 
A)  CH₂O 
B)  C₂H₄O₂ 
C)  C₃H₆O₃ 
D)  C₆H₁₂O6

Question 11

Match each compound with its corresponding percent of sulfur.
-Na?SO?

Accepted Answer

A) 8.7% 
B) 22.6% 
C) 41.1% 
D) 40.6% 
A) 8.7% 
B) 22.6% 
C) 41.1% 
D) 40.6%

Question 12

Which compound has the percent composition of 15.8% Al, 28.1% S and 56.1% O?

Accepted Answer

A)  AL₂(SO₄)3 
B)  AL₂(SO₃)3 
C)  AL₂S3 
D)  AL₂(S2O₃)3 
A)  AL₂(SO₄)3 
B)  AL₂(SO₃)3 
C)  AL₂S3 
D)  AL₂(S2O₃)3

Question 13

26 g of aluminum have the same number of atoms as 26 g of iron.

Accepted Answer

A) True 
 B)False

Question 14

The total number of atoms in two moles SO₃ is ________.

Accepted Answer

A)  4 
B)  8 
C)  1.2 × 1024 
D)  4.8 × 1024 
A)  4 
B)  8 
C)  1.2 × 1024 
D)  4.8 × 1024

Question 15

A sample is composed of 2.78 g of iron and 1.19 g of oxygen. The empirical formula is ________.

Accepted Answer

A)  FeO₂ 
B)  Fe2O5 
C)  Fe2O₃ 
D)  FeO 
A)  FeO₂ 
B)  Fe2O5 
C)  Fe2O₃ 
D)  FeO

Question 16

The theoretical number of moles of copper that will react with 4 moles of sulfuric acid is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

Accepted Answer

A)  2 
B)  4 
C)  6 
D)  8 
A)  2 
B)  4 
C)  6 
D)  8

Question 17

If 14 kg of nitrogen yields 23 kg of nitrogen dioxide, then the percent yield for the reaction is ________. N₂ + 2 O₂ → 2 NO₂

Accepted Answer

A)  100% 
B)  50% 
C)  25% 
D)  12% 
A)  100% 
B)  50% 
C)  25% 
D)  12%

Question 18

There are more atoms in one formula unit of Na3PO₄ than in one molecule of HCl.

Accepted Answer

A) True 
 B)False

Question 19

An iron oxide is 72.4% in iron. Its empirical formula is ________.

Accepted Answer

A)  FeO 
B)  Fe2O 
C)  Fe2O₃ 
D)  Fe₃O₄ 
A)  FeO 
B)  Fe2O 
C)  Fe2O₃ 
D)  Fe₃O₄

Question 20

The empirical formula is never equal to the molecular formula.

Accepted Answer

A) True 
 B)False

Which of the following has the lowest percent of oxygen?

The balanced equation involves the corresponding coefficients ________. NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

The balanced equation involves the corresponding coefficients ________. C₆H₁₄ + O₂ → CO₂ + H₂O

The molecular mass of a compound X(NO₃)₃ is 213. The atomic mass of X is , which is .

What is the percentage by mass of iron (Fe) in the mineral hematite (Fe₂O₃)?

18 g of water have the same number of atoms as 48 g of ozone.

0.68 g of sulfur combine with 1.51 g of chlorine. The empirical formula of this compound is ________.

Alkenes have the general molecular formula CnH₂n. Thus, when n = 2, the alkene is C₂H₄. If an alkene has a molecular mass between 65 and 75, this alkene is ________.

One mole of carbon monoxide has the same mass as one mole of nitrogen gas.

If the empirical formula of a compound is CH₂O and the molecular weight is 180, the molecular formula is ________.

Match each compound with its corresponding percent of sulfur. -Na?SO?

Which compound has the percent composition of 15.8% Al, 28.1% S and 56.1% O?

26 g of aluminum have the same number of atoms as 26 g of iron.

The total number of atoms in two moles SO₃ is ________.

A sample is composed of 2.78 g of iron and 1.19 g of oxygen. The empirical formula is ________.

The theoretical number of moles of copper that will react with 4 moles of sulfuric acid is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

If 14 kg of nitrogen yields 23 kg of nitrogen dioxide, then the percent yield for the reaction is ________. N₂ + 2 O₂ → 2 NO₂

There are more atoms in one formula unit of Na₃PO₄ than in one molecule of HCl.

An iron oxide is 72.4% in iron. Its empirical formula is ________.

The empirical formula is never equal to the molecular formula.

What Is Chemistry

The Numerical Side of Chemistry

The Evolution of Atomic Theory

The Modern Model of the Atom

Chemical Bonding and Nomenclature

The Shape of Molecules

Intermolecular Forces and the Phases of Matter

Chemical Reactions

Electron Transfer in Chemical Reactions

What If There Were No Intermolecular Forces - the Ideal Gas

Solutions

When Reactants Turn Into Products

Chemical Equilibrium

Electrolytes, Acids, and Bases

Nuclear Chemistry

The Chemistry of Carbon

Synthetic and Biological Polymers

Filters

Exam 9: Stoichiometry and the Mole

Which of the following has the lowest percent of oxygen?

The balanced equation involves the corresponding coefficients ________. NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

The balanced equation involves the corresponding coefficients ________. C₆H14 + O₂ → CO₂ + H₂O

The molecular mass of a compound X(NO₃)3 is 213. The atomic mass of X is ________, which is ________.

What is the percentage by mass of iron (Fe) in the mineral hematite (Fe2O₃)?

18 g of water have the same number of atoms as 48 g of ozone.

0.68 g of sulfur combine with 1.51 g of chlorine. The empirical formula of this compound is ________.

Alkenes have the general molecular formula CnH₂n. Thus, when n = 2, the alkene is C₂H₄. If an alkene has a molecular mass between 65 and 75, this alkene is ________.

One mole of carbon monoxide has the same mass as one mole of nitrogen gas.

If the empirical formula of a compound is CH₂O and the molecular weight is 180, the molecular formula is ________.

Match each compound with its corresponding percent of sulfur. -Na?SO?

Which compound has the percent composition of 15.8% Al, 28.1% S and 56.1% O?

26 g of aluminum have the same number of atoms as 26 g of iron.

The total number of atoms in two moles SO₃ is ________.

A sample is composed of 2.78 g of iron and 1.19 g of oxygen. The empirical formula is ________.

The theoretical number of moles of copper that will react with 4 moles of sulfuric acid is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

If 14 kg of nitrogen yields 23 kg of nitrogen dioxide, then the percent yield for the reaction is ________. N₂ + 2 O₂ → 2 NO₂

There are more atoms in one formula unit of Na3PO₄ than in one molecule of HCl.

An iron oxide is 72.4% in iron. Its empirical formula is ________.

The empirical formula is never equal to the molecular formula.

What Is Chemistry

The Numerical Side of Chemistry

The Evolution of Atomic Theory

The Modern Model of the Atom

Chemical Bonding and Nomenclature

The Shape of Molecules

Intermolecular Forces and the Phases of Matter

Chemical Reactions

Electron Transfer in Chemical Reactions

What If There Were No Intermolecular Forces - the Ideal Gas

Solutions

When Reactants Turn Into Products

Chemical Equilibrium

Electrolytes, Acids, and Bases

Nuclear Chemistry

The Chemistry of Carbon

Synthetic and Biological Polymers

Filters

The balanced equation involves the corresponding coefficients ________. C₆H₁₄ + O₂ → CO₂ + H₂O

The molecular mass of a compound X(NO₃)₃ is 213. The atomic mass of X is , which is .

What is the percentage by mass of iron (Fe) in the mineral hematite (Fe₂O₃)?

There are more atoms in one formula unit of Na₃PO₄ than in one molecule of HCl.