Question 1

A sample of oxygen gas that contains one-half of Avogadro's number of molecules has a mass of ________.

Accepted Answer

A)  8.0 g 
B)  16.0 g 
C)  32.0 g 
D)  64.0 g 
A)  8.0 g 
B)  16.0 g 
C)  32.0 g 
D)  64.0 g

Question 2

Alkanes have the general molecular formula CnH₂n+2. Thus, when n = 1, the alkane is CH₄, when n = 2, the alkane is C₂H₆ etc. If an alkane has a molar mass between 140 and 150, this alkane is ________.

Accepted Answer

A)  C9H₂₀ 
B)  C12H26 
C)  C₁₀H22 
D)  C11H24 
A)  C9H₂₀ 
B)  C12H26 
C)  C₁₀H22 
D)  C11H24

Question 3

Which of the following has its empirical formula different than its molecular formula?

Accepted Answer

A)  CH₂S 
B)  C₂H₇N3 
C)  C₃H₆N3 
D)  C₅H₇O₃ 
A)  CH₂S 
B)  C₂H₇N3 
C)  C₃H₆N3 
D)  C₅H₇O₃

Question 4

The percent yield of an experiment in which 2.0 moles of copper was used and 18 g of water was isolated is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

Accepted Answer

A)  100% 
B)  50% 
C)  37.5% 
D)  25% 
A)  100% 
B)  50% 
C)  37.5% 
D)  25%

Question 5

What is the mass of 0.0500 moles aluminum sulfate?

Accepted Answer

A)  6.15 g 
B)  10.95 g 
C)  17.1 g 
D)  19.8 g 
A)  6.15 g 
B)  10.95 g 
C)  17.1 g 
D)  19.8 g

Question 6

Match each compound with its corresponding percent of carbon.
-C?H8CL?O

Accepted Answer

A) 48.6% 
B) 55.6% 
C) 69.0% 
D) 33.6% 
E) 41.8% 
A) 48.6% 
B) 55.6% 
C) 69.0% 
D) 33.6% 
E) 41.8%

Question 7

If the empirical formula is CH₂, and the molecular weight is equal to 180 ±10, then the molecular formula is ________.

Accepted Answer

A)  C₆H₁₂O6 
B)  C14H21 
C)  C₈H₁₂O₄ 
D)  C13H₂6 
A)  C₆H₁₂O6 
B)  C14H21 
C)  C₈H₁₂O₄ 
D)  C13H₂6

Question 8

The molecular formula for a compound with an empirical formula of CH₂O and a molar mass of 120, is C₃H₆O₃.

Accepted Answer

A) True 
 B)False

Question 9

The number of atoms of a certain mass of any compound may be lower than the number of molecules of the same compound.

Accepted Answer

A) True 
 B)False

Question 10

Which statement is true about the empirical formula?

Accepted Answer

A)  The empirical formula is always different than the molecular formula. 
B)  The empirical formula is always the same as the molecular formula. 
C)  The empirical formula may be different than the molecular formula. 
D)  The empirical formula cannot be determined solely by the % composition. 
A)  The empirical formula is always different than the molecular formula. 
B)  The empirical formula is always the same as the molecular formula. 
C)  The empirical formula may be different than the molecular formula. 
D)  The empirical formula cannot be determined solely by the % composition.

Question 11

One mole of methane has the same mass as one mole of oxygen gas.

Accepted Answer

A) True 
 B)False

Question 12

The molar mass of Ca3(PO₄)2 is ________.

Accepted Answer

A)  310 
B)  279 
C)  246 
D)  215 
A)  310 
B)  279 
C)  246 
D)  215

Question 13

Which of the following compounds has its chlorine composition equal to 83.5%?

Accepted Answer

A)  C₂H₃ClO₂ 
B)  C₁₀H17ClS 
C)  CCl4 
D)  CH₂CL₂ 
A)  C₂H₃ClO₂ 
B)  C₁₀H17ClS 
C)  CCl4 
D)  CH₂CL₂

Question 14

The percent composition of carbon is equal to the percent composition of oxygen in carbon monoxide, CO.

Accepted Answer

A) True 
 B)False

Question 15

What is the mass of hydrogen that will react with 0.203 g of Li to form LiH?

Accepted Answer

A)  0.015 g 
B)  0.030 g 
C)  0.060 g 
D)  0.120 g 
A)  0.015 g 
B)  0.030 g 
C)  0.060 g 
D)  0.120 g

Question 16

Match each compound with its corresponding molecular mass.
-KClO?

Accepted Answer

A) 342 
B) 310 
C) 88 
D) 122.5 
A) 342 
B) 310 
C) 88 
D) 122.5

Question 17

A certain compound is found to contain 1.45 g of Na, 2.05 g of S and 1.5 g of O. Its empirical formula is ________.

Accepted Answer

A)  Na₂SO 
B)  NaS2O 
C)  Na₂S2O₃ 
D)  NaSO₂ 
A)  Na₂SO 
B)  NaS2O 
C)  Na₂S2O₃ 
D)  NaSO₂

Question 18

K₄Fe(CN)6 and AL₂(SO₄)3 have the same number of atoms per formula unit.

Accepted Answer

A) True 
 B)False

Question 19

Which of the following does not contain 3.0 × 1024 atoms?

Accepted Answer

A)  60 g of carbon 
B)  one mole of methane 
C)  two moles of water 
D)  160 g sulfur 
A)  60 g of carbon 
B)  one mole of methane 
C)  two moles of water 
D)  160 g sulfur

Question 20

Match each compound with its corresponding percent of carbon.
-C?H??N?

Accepted Answer

A) 48.6% 
B) 55.6% 
C) 69.0% 
D) 33.6% 
E) 41.8% 
A) 48.6% 
B) 55.6% 
C) 69.0% 
D) 33.6% 
E) 41.8%

A sample of oxygen gas that contains one-half of Avogadro's number of molecules has a mass of ________.

Alkanes have the general molecular formula CnH₂n+2. Thus, when n = 1, the alkane is CH₄, when n = 2, the alkane is C₂H₆ etc. If an alkane has a molar mass between 140 and 150, this alkane is ________.

Which of the following has its empirical formula different than its molecular formula?

The percent yield of an experiment in which 2.0 moles of copper was used and 18 g of water was isolated is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

What is the mass of 0.0500 moles aluminum sulfate?

Match each compound with its corresponding percent of carbon. -C?H₈CL?O

If the empirical formula is CH₂, and the molecular weight is equal to 180 ±10, then the molecular formula is ________.

The molecular formula for a compound with an empirical formula of CH₂O and a molar mass of 120, is C₃H₆O₃.

The number of atoms of a certain mass of any compound may be lower than the number of molecules of the same compound.

Which statement is true about the empirical formula?

One mole of methane has the same mass as one mole of oxygen gas.

The molar mass of Ca₃(PO₄)₂ is ________.

Which of the following compounds has its chlorine composition equal to 83.5%?

The percent composition of carbon is equal to the percent composition of oxygen in carbon monoxide, CO.

What is the mass of hydrogen that will react with 0.203 g of Li to form LiH?

Match each compound with its corresponding molecular mass. -KClO?

A certain compound is found to contain 1.45 g of Na, 2.05 g of S and 1.5 g of O. Its empirical formula is ________.

K₄Fe(CN)₆ and AL₂(SO₄)₃ have the same number of atoms per formula unit.

Which of the following does not contain 3.0 × 10²⁴ atoms?

Match each compound with its corresponding percent of carbon. -C?H??N?

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

A sample of oxygen gas that contains one-half of Avogadro's number of molecules has a mass of ________.

Alkanes have the general molecular formula CnH₂n+2. Thus, when n = 1, the alkane is CH₄, when n = 2, the alkane is C₂H₆ etc. If an alkane has a molar mass between 140 and 150, this alkane is ________.

Which of the following has its empirical formula different than its molecular formula?

The percent yield of an experiment in which 2.0 moles of copper was used and 18 g of water was isolated is ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

What is the mass of 0.0500 moles aluminum sulfate?

Match each compound with its corresponding percent of carbon. -C?H8CL?O

If the empirical formula is CH₂, and the molecular weight is equal to 180 ±10, then the molecular formula is ________.

The molecular formula for a compound with an empirical formula of CH₂O and a molar mass of 120, is C₃H₆O₃.

The number of atoms of a certain mass of any compound may be lower than the number of molecules of the same compound.

Which statement is true about the empirical formula?

One mole of methane has the same mass as one mole of oxygen gas.

The molar mass of Ca3(PO₄)2 is ________.

Which of the following compounds has its chlorine composition equal to 83.5%?

The percent composition of carbon is equal to the percent composition of oxygen in carbon monoxide, CO.

What is the mass of hydrogen that will react with 0.203 g of Li to form LiH?

Match each compound with its corresponding molecular mass. -KClO?

A certain compound is found to contain 1.45 g of Na, 2.05 g of S and 1.5 g of O. Its empirical formula is ________.

K₄Fe(CN)6 and AL₂(SO₄)3 have the same number of atoms per formula unit.

Which of the following does not contain 3.0 × 1024 atoms?

Match each compound with its corresponding percent of carbon. -C?H??N?

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

Match each compound with its corresponding percent of carbon. -C?H₈CL?O

The molar mass of Ca₃(PO₄)₂ is ________.

K₄Fe(CN)₆ and AL₂(SO₄)₃ have the same number of atoms per formula unit.

Which of the following does not contain 3.0 × 10²⁴ atoms?