Question 1

Which of the following has the largest percent by mass of carbon?

Accepted Answer

A)   CaCO3
B)   CO2
C)   CH4
D)   NaHCO3E) None of the above
F) All of the above

Question 2

A 2.35-mole sample of H2O2 weighs

Accepted Answer

A)   79.9 g
B)   2.35 g
C)   36.4 g
D)   42.3 g
E)   42.3 amuF) A) and B)
G) A) and C)

Question 3

Which represents the greatest mass?

Accepted Answer

A)   1.0 mol Rb
B)   1.0 mol Ti
C)   1.0 mol Fe
D)   1.0 mol Al
E)   all the sameF) A) and C)
G) A) and E)

Question 4

Convert: 4.13 mol PCl5 = ___________ molecules PCl5

Accepted Answer

A)   2.49 *1024
B)   6.86 * 10-24
C)   1.46 *1023
D)   1.19 * 1022
E)   none of theseF) A) and B)
G) B) and D)

Question 5

The mole can be defined as the number equal to the number of oxygen atoms in 32.00 g of oxygen.

Accepted Answer

A) True 
 B)False

Question 6

Vinegar contains carbon, hydrogen, and oxygen with percent masses of 40.01% C and 6.70% H. If the molar mass of vinegar is about 60 g/mol, what is its molecular formula?

Accepted Answer

A)   CH2O
B)   C3H7O3
C)   C3H8O
D)   C2H20O
E)   C2H4O2F) A) and C)
G) B) and C)

Question 7

What is the percent (by mass)  of carbon in glucose, C6H12O6.

Accepted Answer

A)   40.0 %
B)   53.3 %
C)   25.0 %
D)   6.7 %
E)   none of theseF) All of the above
G) C) and E)

Question 8

How many grams of fluorine are contained in 5 molecules of boron trifluoride?

Accepted Answer

A)   23 g" class="answers-bank-image d-inline" rel="preload" > g
B)   23 g" class="answers-bank-image d-inline" rel="preload" > g
C)   23 g" class="answers-bank-image d-inline" rel="preload" > g
D)   23 g" class="answers-bank-image d-inline" rel="preload" > g
E)   6.022 * 1023 gF) A) and E)
G) B) and C)

Question 9

The mass percent of hydrogen in NH4Br.

Accepted Answer

A)   4.12 %
B)   1.03 %
C)   5.0 %
D)   16.5 %
E)   none of theseF) A) and E)
G) A) and B)

Question 10

The molar mass of ammonium phosphate is

Accepted Answer

A)   149.09 g/mol
B)   113.01 g/mol
C)   302.95 g/mol
D)   165.09 g/mol
E)   133.09 g/molF) B) and C)
G) B) and E) A

Question 11

Consider equal mole samples of dinitrogen monoxide, aluminum nitrate, and potassium cyanide. Rank these from least to greatest number of nitrogen atoms in each sample.

Accepted Answer

A)   potassium cyanide, aluminum nitrate, dinitrogen monoxide
B)   aluminum nitrate, dinitrogen monoxide, potassium cyanide
C)   potassium cyanide, dinitrogen monoxide, aluminum nitrate
D)   aluminum nitrate, potassium cyanide, dinitrogen monoxide
E)   dinitrogen monoxide, aluminum nitrate, potassium cyanideF) B) and C)
G) A) and D)

Question 12

The empirical formula for acetic acid is CH2O. Its molar mass is 60 g/mol. The molecular formula is

Accepted Answer

A)   CH2O
B)   C2H4O2
C)   C2H6O
D)   C2HO2
E)   none of the aboveF) A) and B)
G) A) and E)

Question 13

How many moles of phosphorus are present in 80.0 g of phosphorus?

Accepted Answer

A)   0.387 mol
B)   2.58 mol
C)    mol
D)    mol
E)   none of theseF) A) and B)
G) All of the above

Question 14

A 1.50-mol sample of Zr represents how many atoms?

Accepted Answer

A)   9.03 * 1023 atoms
B)   2.49 *10-24 atoms
C)   4.01 *1023 atoms
D)   8.24 * 1025 atoms
E)   1.64 *10-2 atomsF) A) and D)
G) C) and D)

Question 15

Convert: 0.205 mol Ca(OH) 2 = ___________ g Ca(OH) 2

Accepted Answer

A)   15.2
B)   2.77 *10-3
C)   11.7
D)   361
E)   none of theseF) All of the above
G) B) and C)

Question 16

Calculate the number of moles of Cl2 molecules in a sample that contains 2 molecules in a sample that contains   molecules of Cl2. A)    mol B)    mol C)    mol D)  122.6 mol E)  none of these" class="answers-bank-image d-inline" rel="preload" > molecules of Cl2.

Accepted Answer

A)   2 molecules in a sample that contains   molecules of Cl2. 
A)     mol 
B)     mol 
C)     mol 
D)   122.6 mol 
E)   none of these" class="answers-bank-image d-inline" rel="preload" > mol
B)   2 molecules in a sample that contains   molecules of Cl2. 
A)     mol 
B)     mol 
C)     mol 
D)   122.6 mol 
E)   none of these" class="answers-bank-image d-inline" rel="preload" > mol
C)   2 molecules in a sample that contains   molecules of Cl2. 
A)     mol 
B)     mol 
C)     mol 
D)   122.6 mol 
E)   none of these" class="answers-bank-image d-inline" rel="preload" > mol
D)   122.6 mol
E)   none of theseF) D) and E)
G) C) and D) D

Question 17

Calculate the number of moles in 2.28 g Rb2C2O4.

Accepted Answer

A)   2C2O4. 
A)     mol 
B)   113.6 mol 
C)     mol 
D)     mol 
E)     mol" class="answers-bank-image d-inline" rel="preload" > mol
B)   113.6 mol
C)   2C2O4. 
A)     mol 
B)   113.6 mol 
C)     mol 
D)     mol 
E)     mol" class="answers-bank-image d-inline" rel="preload" > mol
D)   2C2O4. 
A)     mol 
B)   113.6 mol 
C)     mol 
D)     mol 
E)     mol" class="answers-bank-image d-inline" rel="preload" > mol
E)   2C2O4. 
A)     mol 
B)   113.6 mol 
C)     mol 
D)     mol 
E)     mol" class="answers-bank-image d-inline" rel="preload" > molF) C) and D)
G) B) and E)

Question 18

A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen (by mass) . Calculate the empirical formula.

Accepted Answer

A)   CH2O
B)   C2H2O
C)   CH4O
D)   C3H6O3
E)   C2HO2F) All of the above
G) C) and E)

Question 19

What is the molar mass of C3H6O3?

Accepted Answer

A)   90.09 g/mol
B)   94.08 g/mol
C)   54.06 g/mol
D)   84.03 g/mol
E)   none of theseF) A) and B)
G) A) and C)

Question 20

How many atoms of phosphorus are present in 40.8 g of phosphorus?

Accepted Answer

A)    atoms
B)    atoms
C)    atoms
D)    atoms
E)   1.32 atomsF) C) and D)
G) A) and C) A

Exam 8: Chemical Composition

Which of the following has the largest percent by mass of carbon?

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A 2.35-mole sample of H2O2 weighs

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Which represents the greatest mass?

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Convert: 4.13 mol PCl5 = ___________ molecules PCl5

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The mole can be defined as the number equal to the number of oxygen atoms in 32.00 g of oxygen.

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Vinegar contains carbon, hydrogen, and oxygen with percent masses of 40.01% C and 6.70% H. If the molar mass of vinegar is about 60 g/mol, what is its molecular formula?

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What is the percent (by mass) of carbon in glucose, C6H12O6.

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How many grams of fluorine are contained in 5 molecules of boron trifluoride?

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The mass percent of hydrogen in NH4Br.

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The molar mass of ammonium phosphate is

Correct AnswerverifiedA

Consider equal mole samples of dinitrogen monoxide, aluminum nitrate, and potassium cyanide. Rank these from least to greatest number of nitrogen atoms in each sample.

Correct AnswerverifiedShow Answer

The empirical formula for acetic acid is CH2O. Its molar mass is 60 g/mol. The molecular formula is

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How many moles of phosphorus are present in 80.0 g of phosphorus?

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A 1.50-mol sample of Zr represents how many atoms?

Correct AnswerverifiedShow Answer

Convert: 0.205 mol Ca(OH) 2 = ___________ g Ca(OH) 2

Correct AnswerverifiedShow Answer

Calculate the number of moles of Cl2 molecules in a sample that contains molecules of Cl2.

Correct AnswerverifiedD

Calculate the number of moles in 2.28 g Rb2C2O4.

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A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen (by mass) . Calculate the empirical formula.

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What is the molar mass of C3H6O3?

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How many atoms of phosphorus are present in 40.8 g of phosphorus?

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A 2.35-mole sample of H₂O₂ weighs

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Convert: 4.13 mol PCl₅ = ___________ molecules PCl₅

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What is the percent (by mass) of carbon in glucose, C₆H₁₂O₆.

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The mass percent of hydrogen in NH₄Br.

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A

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The empirical formula for acetic acid is CH₂O. Its molar mass is 60 g/mol. The molecular formula is

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Convert: 0.205 mol Ca(OH) ₂ = ___________ g Ca(OH) ₂

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Calculate the number of moles of Cl₂ molecules in a sample that contains molecules of Cl₂.

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Calculate the number of moles in 2.28 g Rb₂C₂O₄.

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What is the molar mass of C₃H₆O₃?

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A