Question 1

What is the mass percent of oxygen in barium perchlorate?

Accepted Answer

A)  4.7%
B)  8.5%
C)  23.4%
D)  38.1%
E)  19.0%

Question 2

What is the percent sodium in sodium carbonate?

Accepted Answer

A)  43.4%
B)  11.3%
C)  45.3%
D)  27.7%
E)  21.7%

Question 3

Determine the empirical formula of a compound that contains 1.409 moles of P and 3.52 moles of O in a particular sample.

Accepted Answer

A)  PO2
B)  PO3
C)  P2O6
D)  P2O5
E)  P2O3

Question 4

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

Question 5

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

Accepted Answer

A)  4.0 × 102 g
B)  25.0 g
C)  17.0 g
D)  4.00 × 10−2 g
E)  2.50 × 10−3 g

Question 6

Calculate the mass of 3.00 moles of CF2Cl2.

Accepted Answer

A)  3.00 g
B)  174 g
C)  363 g
D)  1.81 × 1024 g
E)  40.3

Question 7

Determine the mass of hydrogen (in grams)  that contains 5.08 × 1015 hydrogen atoms.

Accepted Answer

A)  5.12 × 1015 g
B)  3.06 × 1039 g
C)  3.06 × 10−9 g
D)  8.50 × 10−9 g
E)  8.5 × 1015 g

Question 8

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain.Calculate the mass in grams of 3.65 × 1020 molecules of sulfur trioxide.

Accepted Answer

A)  6.06 × 10−4 g
B)  2.91 × 10−2 g
C)  4.85 × 10−2 g
D)  20.6 g
E)  1650 g

Question 9

What is the mass of 7.80 × 1018 carbon atoms? (NA = 6.022 × 1023 mol−1)

Accepted Answer

A)  1.30 × 10−5 g
B)  6.43 × 103 g
C)  7.80 × 1018 g
D)  1.56 × 10−4 g
E)  12.01 g

Question 10

Which of the following is the empirical formula for hexane, C6H14?

Accepted Answer

A)  C12H28
B)  C6H14
C)  C3H7
D)  CH2.3
E)  C0.43H

Question 11

Determine the mass of Sr(C2H3O2) 2 that contains 2.780 Χ 1023 atoms of carbon.

Accepted Answer

A)  205.7 g
B)  57.19 g
C)  46.16 g
D)  94.96 g
E)  23.74 g

Question 12

Which of the following is a molecular formula for a compound with an empirical formula of CH2O and a molar mass of 150.g/mol?

Accepted Answer

A)  C7H18O3
B)  C5H10O5
C)  C3H6O3
D)  CH2O
E)  None of the answers is correct.

Question 13

How many moles are present in 17.4 g of lead?

Accepted Answer

A)  0.0994 moles
B)  1.05 × 1025 moles
C)  0.0840 moles
D)  10.06 moles
E)  11.9 moles

Question 14

How many atoms are in 7.12 mol of gold, Au?

Accepted Answer

A)  1.18 × 10−23 atoms
B)  4.29 × 1024 atoms
C)  8.46 × 1022 atoms
D)  4.70 × 1024 atoms
E)  3.34 × 1026 atoms

Question 15

Aluminum sulfate, Al2(SO4) 3, is used in tanning leather, purifying water, and the manufacture of antiperspirants.Calculate its molecular or formula mass.

Accepted Answer

A)  450.06 amu
B)  342.17 amu
C)  315.15 amu
D)  278.02 amu
E)  74.98 amu

Question 16

Calculate the formula mass of (NH4) 3AsO4.

Accepted Answer

A)  417.80 amu
B)  193.05 amu
C)  165.02 amu
D)  156.96 amu
E)  108.96 amu

Question 17

What is the mass of 0.0250 mol of P2O5?

Accepted Answer

A)  35.5 g
B)  5676 g
C)  0.0250 g
D)  1.51 × 1022 g
E)  3.55 g

Question 18

Household sugar, sucrose, has the molecular formula C12H22O11.What is the % of carbon in sucrose, by mass?

Accepted Answer

A)  26.7%
B)  33.3%
C)  41.4%
D)  42.1%
E)  51.4%

Question 19

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.

Question 20

Which of the following substances contains the greatest mass of carbon?

Accepted Answer

A)  100 g CH4
B)  100 g C2H4
C)  100 g CCl4
D)  100 g CH2Cl2
E)  100 g CO2

Exam 5: The Mole and Chemical Formulas

What is the mass of 7.80 × 1018 carbon atoms? (NA = 6.022 × 1023 mol−1)

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Calculate the mass of 3.00 moles of CF2Cl2.

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Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain.Calculate the mass in grams of 3.65 × 1020 molecules of sulfur trioxide.

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Determine the empirical formula of a compound that contains 1.409 moles of P and 3.52 moles of O in a particular sample.

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What is the mass of 0.0250 mol of P2O5?

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How many atoms are in 7.12 mol of gold, Au?

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Which of the following is the empirical formula for hexane, C6H14?

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

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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.

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Household sugar, sucrose, has the molecular formula C12H22O11.What is the % of carbon in sucrose, by mass?

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Calculate the formula mass of (NH4) 3AsO4.

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How many moles are present in 17.4 g of lead?

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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?

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Which of the following substances contains the greatest mass of carbon?

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What is the percent sodium in sodium carbonate?

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Determine the mass of hydrogen (in grams) that contains 5.08 × 1015 hydrogen atoms.

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Aluminum sulfate, Al2(SO4) 3, is used in tanning leather, purifying water, and the manufacture of antiperspirants.Calculate its molecular or formula mass.

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What is the mass percent of oxygen in barium perchlorate?

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Determine the mass of Sr(C2H3O2) 2 that contains 2.780 Χ 1023 atoms of carbon.

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Which of the following is a molecular formula for a compound with an empirical formula of CH2O and a molar mass of 150.g/mol?

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What is the mass of 7.80 × 10¹⁸ carbon atoms? (N_A = 6.022 × 10²³ mol⁻¹)

Correct Answer
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Calculate the mass of 3.00 moles of CF₂Cl₂.

Correct Answer
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Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain.Calculate the mass in grams of 3.65 × 10²⁰ molecules of sulfur trioxide.

Correct Answer
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What is the mass of 0.0250 mol of P₂O₅?

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Which of the following is the empirical formula for hexane, C₆H₁₄?

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Household sugar, sucrose, has the molecular formula C₁₂H₂₂O₁₁.What is the % of carbon in sucrose, by mass?

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Calculate the formula mass of (NH₄) ₃AsO₄.

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Determine the mass of hydrogen (in grams) that contains 5.08 × 10¹⁵ hydrogen atoms.

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Aluminum sulfate, Al₂(SO₄) ₃, is used in tanning leather, purifying water, and the manufacture of antiperspirants.Calculate its molecular or formula mass.

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Determine the mass of Sr(C₂H₃O₂) ₂ that contains 2.780 Χ 10²³ atoms of carbon.

Correct Answer
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Which of the following is a molecular formula for a compound with an empirical formula of CH₂O and a molar mass of 150.g/mol?

Correct Answer
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