Question 1

There are ________ hydrogen atoms in 25 molecules of C4H4S2.

Accepted Answer

A)  25
B)  3.8 × 1024
C)  6.0 × 1025
D)  100
E)  1.5 × 1025F) B) and C)
G) C) and D)

Question 2

There are ________ oxygen atoms in 30 molecules of C20H42S3O2.

Accepted Answer

A)  6.0 × 1023
B)  1.8 × 1025
C)  3.6 × 1025
D)  1.2 × 1024
E)  60F) D) and E)
G) A) and C)

Question 3

How many moles of lithium phosphate (Li3PO4) are contained in 66.6 g of lithium phosphate?

Accepted Answer

A)  0.575
B)  7710
C)  1.11 × 10-22
D)  4.01 × 1025
E)  116F) A) and D)
G) B) and E)

Question 4

Write the balanced equation for the reaction that occurs when methanol,CH3OH (l) ,is burned in air. What is the coefficient of methanol in the balanced equation?

Accepted Answer

A)  1
B)  2
C)  3
D)  4
E)  3/2F) B) and E)
G) None of the above

Question 5

One mole of ________ contains the smallest number of atoms.

Accepted Answer

A)  S8
B)  C10H8
C)  Al2(SO4) 3
D)  Na3PO4
E)  NaClF) A) and E)
G) All of the above

Question 6

Which of the following are decomposition reactions?
1. CH4 (g)  + O2 (g)   →\rightarrow→  CO2 (g)  + H2O (l)  
2. CaO (s)  + CO2 (g)   →\rightarrow→ CaCO3 (s) 
3. Mg (s)  + O2(g)   →\rightarrow→  MgO (s)  
4. PbCO3 (s)   →\rightarrow→  PbO (s)  + CO2 (g)

Accepted Answer

A)   1, 2, and 3
B)   4 only
C)   1, 2, 3, and 4
D)   2 and 3
E)   2, 3, and 4 F) D) and E)
G) A) and E)

Question 7

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) 
How many moles of N2 are needed to react with 0.550 mol of lithium?

Accepted Answer

A)  3.30
B)  0.550
C)  0.183
D)  1.65
E)  0.0917F) C) and D)
G) B) and E)

Question 8

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO3 (s) → PbO (s) + CO2 (g) 
How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?

Accepted Answer

A)  0.41
B)  2.50
C)  0.00936
D)  2.09
E)  2.61F) B) and C)
G) D) and E)

Question 9

How many grams of phenol (C6H5OH) are contained in 5.50 mol of phenol?

Accepted Answer

A)  518
B)  0.0584
C)  9.14 × 10-24
D)  3.31 × 1024
E)  94.1F) A) and E)
G) A) and C)

Question 10

A compound contains 38.7% K,13.9% N,and 47.4% O by mass.What is the empirical formula of the compound?

Accepted Answer

A)  KNO3
B)  K2N2O3
C)  KNO2
D)  K2NO3
E)  K4NO5F) D) and E)
G) A) and B)

Question 11

When the following equation is balanced,the coefficient of H2SO4 is ________. H2SO4 (aq) + NaOH (aq) → Na2SO4 (aq) + H2O (l)

Accepted Answer

A)  1
B)  2
C)  3
D)  4
E)  0.5F) C) and E)
G) A) and B)

Question 12

A 1.038 g sample of unknown containing C,H,and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis.Determine the empirical formula of the compound.

Accepted Answer

A)  C3H3O
B)  C6H6O
C)  CH3O
D)  C6H6O2
E)  C2H6O2F) A) and C)
G) A) and D)

Question 13

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s) + 3F2 (g) → SF6 (g) 
In a particular experiment,the percent yield is 83.1%. This means that in this experiment,a 4.50 g sample of fluorine yields ________ g of SF6 .

Accepted Answer

A)  9.58
B)  3.74
C)  4.79
D)  43.1
E)  14.4F) D) and E)
G) A) and B)

Question 14

When the following equation is balanced,the coefficient of sulfur dioxide is ________. PbS (s) + O2 (g) → PbO (s) + SO2 (g)

Accepted Answer

A)  5
B)  1
C)  3
D)  2
E)  4F) A) and D)
G) B) and E)

Question 15

Balance the following reaction and determine the coefficient of H2O. CO (g) + H2 (g) → H2O (g) + CH4 (g)

Accepted Answer

A)  1
B)  2
C)  3
D)  4
E)  0F) B) and D)
G) A) and B)

Question 16

1 mole of which of the following will contain the largest number of atoms?

Accepted Answer

A)  sodium
B)  magnesium
C)  mercury
D)  neon
E)  1 mole of any element will contain the same number of atoms.F) B) and D)
G) C) and E)

Question 17

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s) + 3O2 (g) → 2Al2O3 (s) 
The maximum amount of Al2O3 that can be produced from 5.0 g of Al and 5.0 g of O2 is ________ g.

Accepted Answer

A)  19
B)  4.7
C)  9.4
D)  11
E)  2.5F) A) and B)
G) All of the above

Question 18

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2) as shown in the unbalanced reaction below: CaC2 (s) + H2O (g) → Ca(OH) 2 (s) + C2H2 (g) 
How many grams of H2O are required to completely react with 82.4 g of CaC2.

Accepted Answer

A)  1.29
B)  11.6
C)  46.3
D)  23.2
E)  18.0F) B) and C)
G) C) and D)

Question 19

There are ________ mol of carbon atoms in 5 mol of dimethylsulfoxide (C2H6SO) .

Accepted Answer

A)  2
B)  5
C)  10
D)  12
E)  50F) B) and C)
G) All of the above

Question 20

A compound contains 40.0% C,6.71% H,and 53.29% O by mass.The molecular weight of the compound is 60.05 amu.The molecular formula of this compound is ________.

Accepted Answer

A)  C2H4O2
B)  CH2O
C)  C2H3O4
D)  C2H2O4
E)  CHO2F) A) and D)
G) C) and E)

Exam 3: Chemical Reactions and Reaction Stoichiometry

How many grams of phenol (C6H5OH) are contained in 5.50 mol of phenol?

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Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s) + 3O2 (g) → 2Al2O3 (s) The maximum amount of Al2O3 that can be produced from 5.0 g of Al and 5.0 g of O2 is ________ g.

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A 1.038 g sample of unknown containing C,H,and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis.Determine the empirical formula of the compound.

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A compound contains 38.7% K,13.9% N,and 47.4% O by mass.What is the empirical formula of the compound?

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Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2) as shown in the unbalanced reaction below: CaC2 (s) + H2O (g) → Ca(OH) 2 (s) + C2H2 (g) How many grams of H2O are required to completely react with 82.4 g of CaC2.

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Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO3 (s) → PbO (s) + CO2 (g) How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?

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Which of the following are decomposition reactions? 1. CH4 (g) + O2 (g) →\rightarrow→ CO2 (g) + H2O (l) 2. CaO (s) + CO2 (g) →\rightarrow→ CaCO3 (s) 3. Mg (s) + O2(g) →\rightarrow→ MgO (s) 4. PbCO3 (s) →\rightarrow→ PbO (s) + CO2 (g)

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When the following equation is balanced,the coefficient of H2SO4 is ________. H2SO4 (aq) + NaOH (aq) → Na2SO4 (aq) + H2O (l)

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There are ________ hydrogen atoms in 25 molecules of C4H4S2.

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Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of N2 are needed to react with 0.550 mol of lithium?

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There are ________ mol of carbon atoms in 5 mol of dimethylsulfoxide (C2H6SO) .

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A compound contains 40.0% C,6.71% H,and 53.29% O by mass.The molecular weight of the compound is 60.05 amu.The molecular formula of this compound is ________.

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When the following equation is balanced,the coefficient of sulfur dioxide is ________. PbS (s) + O2 (g) → PbO (s) + SO2 (g)

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Write the balanced equation for the reaction that occurs when methanol,CH3OH (l) ,is burned in air. What is the coefficient of methanol in the balanced equation?

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How many moles of lithium phosphate (Li3PO4) are contained in 66.6 g of lithium phosphate?

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One mole of ________ contains the smallest number of atoms.

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There are ________ oxygen atoms in 30 molecules of C20H42S3O2.

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Balance the following reaction and determine the coefficient of H2O. CO (g) + H2 (g) → H2O (g) + CH4 (g)

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Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s) + 3F2 (g) → SF6 (g) In a particular experiment,the percent yield is 83.1%. This means that in this experiment,a 4.50 g sample of fluorine yields ________ g of SF6 .

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1 mole of which of the following will contain the largest number of atoms?

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How many grams of phenol (C₆H₅OH) are contained in 5.50 mol of phenol?

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Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide: 4Al (s) + 3O₂ (g) → 2Al₂O₃ (s) The maximum amount of Al₂O₃ that can be produced from 5.0 g of Al and 5.0 g of O₂is ________ g.

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A 1.038 g sample of unknown containing C,H,and O yielded 2.48 g of CO₂ and 0.510 g of H₂O during combustion analysis.Determine the empirical formula of the compound.

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Calcium carbide (CaC₂) reacts with water to produce acetylene (C₂H₂) as shown in the unbalanced reaction below: CaC₂ (s) + H₂O (g) → Ca(OH) ₂ (s) + C₂H₂ (g) How many grams of H₂O are required to completely react with 82.4 g of CaC₂.

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Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO₃ (s) → PbO (s) + CO₂(g) How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?

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Which of the following are decomposition reactions? 1. CH₄ (g) + O₂ (g) $\rightarrow$ CO₂ (g) + H₂O (l) 2. CaO (s) + CO₂(g) $\rightarrow$ CaCO₃ (s) 3. Mg (s) + O₂(g) $\rightarrow$ MgO (s) 4. PbCO₃ (s) $\rightarrow$ PbO (s) + CO₂ (g)

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When the following equation is balanced,the coefficient of H₂SO₄ is ________. H₂SO₄(aq) + NaOH (aq) → Na₂SO₄(aq) + H₂O (l)

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There are ________ hydrogen atoms in 25 molecules of C₄H₄S₂.

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Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of N₂are needed to react with 0.550 mol of lithium?

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There are ________ mol of carbon atoms in 5 mol of dimethylsulfoxide (C₂H₆SO) .

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When the following equation is balanced,the coefficient of sulfur dioxide is ________. PbS (s) + O₂(g) → PbO (s) + SO₂(g)

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Write the balanced equation for the reaction that occurs when methanol,CH₃OH (l) ,is burned in air. What is the coefficient of methanol in the balanced equation?

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How many moles of lithium phosphate (Li₃PO₄) are contained in 66.6 g of lithium phosphate?

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There are ________ oxygen atoms in 30 molecules of C₂₀H₄₂S₃O₂.

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Balance the following reaction and determine the coefficient of H₂O. CO (g) + H₂(g) → H₂O (g) + CH₄(g)

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Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride: S (s) + 3F₂(g) → SF₆(g) In a particular experiment,the percent yield is 83.1%. This means that in this experiment,a 4.50 g sample of fluorine yields ________ g of SF_{6 .}

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